merge(third_party/git): Merge squashed git subtree at v2.23.0 r/373

Merge commit '1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5' as 'third_party/git'

23 files changed, 9267 insertions, 0 deletions

diff --git a/third_party/git/perl/.gitignore b/third_party/git/perl/.gitignore
new file mode 100644
index 000000000000..84c048a73cc2
--- /dev/null
+++ b/third_party/git/perl/.gitignore
@@ -0,0 +1 @@
+/build/
diff --git a/third_party/git/perl/FromCPAN/.gitattributes b/third_party/git/perl/FromCPAN/.gitattributes
new file mode 100644
index 000000000000..8b64fc5e227a
--- /dev/null
+++ b/third_party/git/perl/FromCPAN/.gitattributes
@@ -0,0 +1 @@
+/Error.pm whitespace=-blank-at-eof
diff --git a/third_party/git/perl/FromCPAN/Error.pm b/third_party/git/perl/FromCPAN/Error.pm
new file mode 100644
index 000000000000..8b95e2d73d0f
--- /dev/null
+++ b/third_party/git/perl/FromCPAN/Error.pm
@@ -0,0 +1,1040 @@
+# Error.pm
+#
+# Copyright (c) 1997-8 Graham Barr <gbarr@ti.com>. All rights reserved.
+# This program is free software; you can redistribute it and/or
+# modify it under the same terms as Perl itself.
+#
+# Based on my original Error.pm, and Exceptions.pm by Peter Seibel
+# <peter@weblogic.com> and adapted by Jesse Glick <jglick@sig.bsh.com>.
+#
+# but modified ***significantly***
+
+package Error;
+
+use strict;
+use warnings;
+
+use vars qw($VERSION);
+use 5.004;
+
+$VERSION = "0.17025";
+
+use overload (
+	'""'	   =>	'stringify',
+	'0+'	   =>	'value',
+	'bool'     =>	sub { return 1; },
+	'fallback' =>	1
+);
+
+$Error::Depth = 0;	# Depth to pass to caller()
+$Error::Debug = 0;	# Generate verbose stack traces
+@Error::STACK = ();	# Clause stack for try
+$Error::THROWN = undef;	# last error thrown, a workaround until die $ref works
+
+my $LAST;		# Last error created
+my %ERROR;		# Last error associated with package
+
+sub _throw_Error_Simple
+{
+    my $args = shift;
+    return Error::Simple->new($args->{'text'});
+}
+
+$Error::ObjectifyCallback = \&_throw_Error_Simple;
+
+
+# Exported subs are defined in Error::subs
+
+use Scalar::Util ();
+
+sub import {
+    shift;
+    my @tags = @_;
+    local $Exporter::ExportLevel = $Exporter::ExportLevel + 1;
+
+    @tags = grep {
+       if( $_ eq ':warndie' ) {
+          Error::WarnDie->import();
+          0;
+       }
+       else {
+          1;
+       }
+    } @tags;
+
+    Error::subs->import(@tags);
+}
+
+# I really want to use last for the name of this method, but it is a keyword
+# which prevent the syntax  last Error
+
+sub prior {
+    shift; # ignore
+
+    return $LAST unless @_;
+
+    my $pkg = shift;
+    return exists $ERROR{$pkg} ? $ERROR{$pkg} : undef
+	unless ref($pkg);
+
+    my $obj = $pkg;
+    my $err = undef;
+    if($obj->isa('HASH')) {
+	$err = $obj->{'__Error__'}
+	    if exists $obj->{'__Error__'};
+    }
+    elsif($obj->isa('GLOB')) {
+	$err = ${*$obj}{'__Error__'}
+	    if exists ${*$obj}{'__Error__'};
+    }
+
+    $err;
+}
+
+sub flush {
+    shift; #ignore
+
+    unless (@_) {
+       $LAST = undef;
+       return;
+    }
+
+    my $pkg = shift;
+    return unless ref($pkg);
+
+    undef $ERROR{$pkg} if defined $ERROR{$pkg};
+}
+
+# Return as much information as possible about where the error
+# happened. The -stacktrace element only exists if $Error::DEBUG
+# was set when the error was created
+
+sub stacktrace {
+    my $self = shift;
+
+    return $self->{'-stacktrace'}
+	if exists $self->{'-stacktrace'};
+
+    my $text = exists $self->{'-text'} ? $self->{'-text'} : "Died";
+
+    $text .= sprintf(" at %s line %d.\n", $self->file, $self->line)
+	unless($text =~ /\n$/s);
+
+    $text;
+}
+
+
+sub associate {
+    my $err = shift;
+    my $obj = shift;
+
+    return unless ref($obj);
+
+    if($obj->isa('HASH')) {
+	$obj->{'__Error__'} = $err;
+    }
+    elsif($obj->isa('GLOB')) {
+	${*$obj}{'__Error__'} = $err;
+    }
+    $obj = ref($obj);
+    $ERROR{ ref($obj) } = $err;
+
+    return;
+}
+
+
+sub new {
+    my $self = shift;
+    my($pkg,$file,$line) = caller($Error::Depth);
+
+    my $err = bless {
+	'-package' => $pkg,
+	'-file'    => $file,
+	'-line'    => $line,
+	@_
+    }, $self;
+
+    $err->associate($err->{'-object'})
+	if(exists $err->{'-object'});
+
+    # To always create a stacktrace would be very inefficient, so
+    # we only do it if $Error::Debug is set
+
+    if($Error::Debug) {
+	require Carp;
+	local $Carp::CarpLevel = $Error::Depth;
+	my $text = defined($err->{'-text'}) ? $err->{'-text'} : "Error";
+	my $trace = Carp::longmess($text);
+	# Remove try calls from the trace
+	$trace =~ s/(\n\s+\S+__ANON__[^\n]+)?\n\s+eval[^\n]+\n\s+Error::subs::try[^\n]+(?=\n)//sog;
+	$trace =~ s/(\n\s+\S+__ANON__[^\n]+)?\n\s+eval[^\n]+\n\s+Error::subs::run_clauses[^\n]+\n\s+Error::subs::try[^\n]+(?=\n)//sog;
+	$err->{'-stacktrace'} = $trace
+    }
+
+    $@ = $LAST = $ERROR{$pkg} = $err;
+}
+
+# Throw an error. this contains some very gory code.
+
+sub throw {
+    my $self = shift;
+    local $Error::Depth = $Error::Depth + 1;
+
+    # if we are not rethrow-ing then create the object to throw
+    $self = $self->new(@_) unless ref($self);
+
+    die $Error::THROWN = $self;
+}
+
+# syntactic sugar for
+#
+#    die with Error( ... );
+
+sub with {
+    my $self = shift;
+    local $Error::Depth = $Error::Depth + 1;
+
+    $self->new(@_);
+}
+
+# syntactic sugar for
+#
+#    record Error( ... ) and return;
+
+sub record {
+    my $self = shift;
+    local $Error::Depth = $Error::Depth + 1;
+
+    $self->new(@_);
+}
+
+# catch clause for
+#
+# try { ... } catch CLASS with { ... }
+
+sub catch {
+    my $pkg = shift;
+    my $code = shift;
+    my $clauses = shift || {};
+    my $catch = $clauses->{'catch'} ||= [];
+
+    unshift @$catch,  $pkg, $code;
+
+    $clauses;
+}
+
+# Object query methods
+
+sub object {
+    my $self = shift;
+    exists $self->{'-object'} ? $self->{'-object'} : undef;
+}
+
+sub file {
+    my $self = shift;
+    exists $self->{'-file'} ? $self->{'-file'} : undef;
+}
+
+sub line {
+    my $self = shift;
+    exists $self->{'-line'} ? $self->{'-line'} : undef;
+}
+
+sub text {
+    my $self = shift;
+    exists $self->{'-text'} ? $self->{'-text'} : undef;
+}
+
+# overload methods
+
+sub stringify {
+    my $self = shift;
+    defined $self->{'-text'} ? $self->{'-text'} : "Died";
+}
+
+sub value {
+    my $self = shift;
+    exists $self->{'-value'} ? $self->{'-value'} : undef;
+}
+
+package Error::Simple;
+
+use vars qw($VERSION);
+
+$VERSION = "0.17025";
+
+@Error::Simple::ISA = qw(Error);
+
+sub new {
+    my $self  = shift;
+    my $text  = "" . shift;
+    my $value = shift;
+    my(@args) = ();
+
+    local $Error::Depth = $Error::Depth + 1;
+
+    @args = ( -file => $1, -line => $2)
+	if($text =~ s/\s+at\s+(\S+)\s+line\s+(\d+)(?:,\s*<[^>]*>\s+line\s+\d+)?\.?\n?$//s);
+    push(@args, '-value', 0 + $value)
+	if defined($value);
+
+    $self->SUPER::new(-text => $text, @args);
+}
+
+sub stringify {
+    my $self = shift;
+    my $text = $self->SUPER::stringify;
+    $text .= sprintf(" at %s line %d.\n", $self->file, $self->line)
+	unless($text =~ /\n$/s);
+    $text;
+}
+
+##########################################################################
+##########################################################################
+
+# Inspired by code from Jesse Glick <jglick@sig.bsh.com> and
+# Peter Seibel <peter@weblogic.com>
+
+package Error::subs;
+
+use Exporter ();
+use vars qw(@EXPORT_OK @ISA %EXPORT_TAGS);
+
+@EXPORT_OK   = qw(try with finally except otherwise);
+%EXPORT_TAGS = (try => \@EXPORT_OK);
+
+@ISA = qw(Exporter);
+
+sub run_clauses ($$$\@) {
+    my($clauses,$err,$wantarray,$result) = @_;
+    my $code = undef;
+
+    $err = $Error::ObjectifyCallback->({'text' =>$err}) unless ref($err);
+
+    CATCH: {
+
+	# catch
+	my $catch;
+	if(defined($catch = $clauses->{'catch'})) {
+	    my $i = 0;
+
+	    CATCHLOOP:
+	    for( ; $i < @$catch ; $i += 2) {
+		my $pkg = $catch->[$i];
+		unless(defined $pkg) {
+		    #except
+		    splice(@$catch,$i,2,$catch->[$i+1]->($err));
+		    $i -= 2;
+		    next CATCHLOOP;
+		}
+		elsif(Scalar::Util::blessed($err) && $err->isa($pkg)) {
+		    $code = $catch->[$i+1];
+		    while(1) {
+			my $more = 0;
+			local($Error::THROWN, $@);
+			my $ok = eval {
+			    $@ = $err;
+			    if($wantarray) {
+				@{$result} = $code->($err,\$more);
+			    }
+			    elsif(defined($wantarray)) {
+			        @{$result} = ();
+				$result->[0] = $code->($err,\$more);
+			    }
+			    else {
+				$code->($err,\$more);
+			    }
+			    1;
+			};
+			if( $ok ) {
+			    next CATCHLOOP if $more;
+			    undef $err;
+			}
+			else {
+			    $err = $@ || $Error::THROWN;
+				$err = $Error::ObjectifyCallback->({'text' =>$err})
+					unless ref($err);
+			}
+			last CATCH;
+		    };
+		}
+	    }
+	}
+
+	# otherwise
+	my $owise;
+	if(defined($owise = $clauses->{'otherwise'})) {
+	    my $code = $clauses->{'otherwise'};
+	    my $more = 0;
+        local($Error::THROWN, $@);
+	    my $ok = eval {
+		$@ = $err;
+		if($wantarray) {
+		    @{$result} = $code->($err,\$more);
+		}
+		elsif(defined($wantarray)) {
+		    @{$result} = ();
+		    $result->[0] = $code->($err,\$more);
+		}
+		else {
+		    $code->($err,\$more);
+		}
+		1;
+	    };
+	    if( $ok ) {
+		undef $err;
+	    }
+	    else {
+		$err = $@ || $Error::THROWN;
+
+		$err = $Error::ObjectifyCallback->({'text' =>$err})
+			unless ref($err);
+	    }
+	}
+    }
+    $err;
+}
+
+sub try (&;$) {
+    my $try = shift;
+    my $clauses = @_ ? shift : {};
+    my $ok = 0;
+    my $err = undef;
+    my @result = ();
+
+    unshift @Error::STACK, $clauses;
+
+    my $wantarray = wantarray();
+
+    do {
+	local $Error::THROWN = undef;
+	local $@ = undef;
+
+	$ok = eval {
+	    if($wantarray) {
+		@result = $try->();
+	    }
+	    elsif(defined $wantarray) {
+		$result[0] = $try->();
+	    }
+	    else {
+		$try->();
+	    }
+	    1;
+	};
+
+	$err = $@ || $Error::THROWN
+	    unless $ok;
+    };
+
+    shift @Error::STACK;
+
+    $err = run_clauses($clauses,$err,wantarray,@result)
+    unless($ok);
+
+    $clauses->{'finally'}->()
+	if(defined($clauses->{'finally'}));
+
+    if (defined($err))
+    {
+        if (Scalar::Util::blessed($err) && $err->can('throw'))
+        {
+            throw $err;
+        }
+        else
+        {
+            die $err;
+        }
+    }
+
+    wantarray ? @result : $result[0];
+}
+
+# Each clause adds a sub to the list of clauses. The finally clause is
+# always the last, and the otherwise clause is always added just before
+# the finally clause.
+#
+# All clauses, except the finally clause, add a sub which takes one argument
+# this argument will be the error being thrown. The sub will return a code ref
+# if that clause can handle that error, otherwise undef is returned.
+#
+# The otherwise clause adds a sub which unconditionally returns the users
+# code reference, this is why it is forced to be last.
+#
+# The catch clause is defined in Error.pm, as the syntax causes it to
+# be called as a method
+
+sub with (&;$) {
+    @_
+}
+
+sub finally (&) {
+    my $code = shift;
+    my $clauses = { 'finally' => $code };
+    $clauses;
+}
+
+# The except clause is a block which returns a hashref or a list of
+# key-value pairs, where the keys are the classes and the values are subs.
+
+sub except (&;$) {
+    my $code = shift;
+    my $clauses = shift || {};
+    my $catch = $clauses->{'catch'} ||= [];
+
+    my $sub = sub {
+	my $ref;
+	my(@array) = $code->($_[0]);
+	if(@array == 1 && ref($array[0])) {
+	    $ref = $array[0];
+	    $ref = [ %$ref ]
+		if(UNIVERSAL::isa($ref,'HASH'));
+	}
+	else {
+	    $ref = \@array;
+	}
+	@$ref
+    };
+
+    unshift @{$catch}, undef, $sub;
+
+    $clauses;
+}
+
+sub otherwise (&;$) {
+    my $code = shift;
+    my $clauses = shift || {};
+
+    if(exists $clauses->{'otherwise'}) {
+	require Carp;
+	Carp::croak("Multiple otherwise clauses");
+    }
+
+    $clauses->{'otherwise'} = $code;
+
+    $clauses;
+}
+
+1;
+
+package Error::WarnDie;
+
+sub gen_callstack($)
+{
+    my ( $start ) = @_;
+
+    require Carp;
+    local $Carp::CarpLevel = $start;
+    my $trace = Carp::longmess("");
+    # Remove try calls from the trace
+    $trace =~ s/(\n\s+\S+__ANON__[^\n]+)?\n\s+eval[^\n]+\n\s+Error::subs::try[^\n]+(?=\n)//sog;
+    $trace =~ s/(\n\s+\S+__ANON__[^\n]+)?\n\s+eval[^\n]+\n\s+Error::subs::run_clauses[^\n]+\n\s+Error::subs::try[^\n]+(?=\n)//sog;
+    my @callstack = split( m/\n/, $trace );
+    return @callstack;
+}
+
+my $old_DIE;
+my $old_WARN;
+
+sub DEATH
+{
+    my ( $e ) = @_;
+
+    local $SIG{__DIE__} = $old_DIE if( defined $old_DIE );
+
+    die @_ if $^S;
+
+    my ( $etype, $message, $location, @callstack );
+    if ( ref($e) && $e->isa( "Error" ) ) {
+        $etype = "exception of type " . ref( $e );
+        $message = $e->text;
+        $location = $e->file . ":" . $e->line;
+        @callstack = split( m/\n/, $e->stacktrace );
+    }
+    else {
+        # Don't apply subsequent layer of message formatting
+        die $e if( $e =~ m/^\nUnhandled perl error caught at toplevel:\n\n/ );
+        $etype = "perl error";
+        my $stackdepth = 0;
+        while( caller( $stackdepth ) =~ m/^Error(?:$|::)/ ) {
+            $stackdepth++
+        }
+
+        @callstack = gen_callstack( $stackdepth + 1 );
+
+        $message = "$e";
+        chomp $message;
+
+        if ( $message =~ s/ at (.*?) line (\d+)\.$// ) {
+            $location = $1 . ":" . $2;
+        }
+        else {
+            my @caller = caller( $stackdepth );
+            $location = $caller[1] . ":" . $caller[2];
+        }
+    }
+
+    shift @callstack;
+    # Do it this way in case there are no elements; we don't print a spurious \n
+    my $callstack = join( "", map { "$_\n"} @callstack );
+
+    die "\nUnhandled $etype caught at toplevel:\n\n  $message\n\nThrown from: $location\n\nFull stack trace:\n\n$callstack\n";
+}
+
+sub TAXES
+{
+    my ( $message ) = @_;
+
+    local $SIG{__WARN__} = $old_WARN if( defined $old_WARN );
+
+    $message =~ s/ at .*? line \d+\.$//;
+    chomp $message;
+
+    my @callstack = gen_callstack( 1 );
+    my $location = shift @callstack;
+
+    # $location already starts in a leading space
+    $message .= $location;
+
+    # Do it this way in case there are no elements; we don't print a spurious \n
+    my $callstack = join( "", map { "$_\n"} @callstack );
+
+    warn "$message:\n$callstack";
+}
+
+sub import
+{
+    $old_DIE  = $SIG{__DIE__};
+    $old_WARN = $SIG{__WARN__};
+
+    $SIG{__DIE__}  = \&DEATH;
+    $SIG{__WARN__} = \&TAXES;
+}
+
+1;
+
+__END__
+
+=head1 NAME
+
+Error - Error/exception handling in an OO-ish way
+
+=head1 WARNING
+
+Using the "Error" module is B<no longer recommended> due to the black-magical
+nature of its syntactic sugar, which often tends to break. Its maintainers
+have stopped actively writing code that uses it, and discourage people
+from doing so. See the "SEE ALSO" section below for better recommendations.
+
+=head1 SYNOPSIS
+
+    use Error qw(:try);
+
+    throw Error::Simple( "A simple error");
+
+    sub xyz {
+        ...
+	record Error::Simple("A simple error")
+	    and return;
+    }
+
+    unlink($file) or throw Error::Simple("$file: $!",$!);
+
+    try {
+	do_some_stuff();
+	die "error!" if $condition;
+	throw Error::Simple "Oops!" if $other_condition;
+    }
+    catch Error::IO with {
+	my $E = shift;
+	print STDERR "File ", $E->{'-file'}, " had a problem\n";
+    }
+    except {
+	my $E = shift;
+	my $general_handler=sub {send_message $E->{-description}};
+	return {
+	    UserException1 => $general_handler,
+	    UserException2 => $general_handler
+	};
+    }
+    otherwise {
+	print STDERR "Well I don't know what to say\n";
+    }
+    finally {
+	close_the_garage_door_already(); # Should be reliable
+    }; # Don't forget the trailing ; or you might be surprised
+
+=head1 DESCRIPTION
+
+The C<Error> package provides two interfaces. Firstly C<Error> provides
+a procedural interface to exception handling. Secondly C<Error> is a
+base class for errors/exceptions that can either be thrown, for
+subsequent catch, or can simply be recorded.
+
+Errors in the class C<Error> should not be thrown directly, but the
+user should throw errors from a sub-class of C<Error>.
+
+=head1 PROCEDURAL INTERFACE
+
+C<Error> exports subroutines to perform exception handling. These will
+be exported if the C<:try> tag is used in the C<use> line.
+
+=over 4
+
+=item try BLOCK CLAUSES
+
+C<try> is the main subroutine called by the user. All other subroutines
+exported are clauses to the try subroutine.
+
+The BLOCK will be evaluated and, if no error is throw, try will return
+the result of the block.
+
+C<CLAUSES> are the subroutines below, which describe what to do in the
+event of an error being thrown within BLOCK.
+
+=item catch CLASS with BLOCK
+
+This clauses will cause all errors that satisfy C<$err-E<gt>isa(CLASS)>
+to be caught and handled by evaluating C<BLOCK>.
+
+C<BLOCK> will be passed two arguments. The first will be the error
+being thrown. The second is a reference to a scalar variable. If this
+variable is set by the catch block then, on return from the catch
+block, try will continue processing as if the catch block was never
+found. The error will also be available in C<$@>.
+
+To propagate the error the catch block may call C<$err-E<gt>throw>
+
+If the scalar reference by the second argument is not set, and the
+error is not thrown. Then the current try block will return with the
+result from the catch block.
+
+=item except BLOCK
+
+When C<try> is looking for a handler, if an except clause is found
+C<BLOCK> is evaluated. The return value from this block should be a
+HASHREF or a list of key-value pairs, where the keys are class names
+and the values are CODE references for the handler of errors of that
+type.
+
+=item otherwise BLOCK
+
+Catch any error by executing the code in C<BLOCK>
+
+When evaluated C<BLOCK> will be passed one argument, which will be the
+error being processed. The error will also be available in C<$@>.
+
+Only one otherwise block may be specified per try block
+
+=item finally BLOCK
+
+Execute the code in C<BLOCK> either after the code in the try block has
+successfully completed, or if the try block throws an error then
+C<BLOCK> will be executed after the handler has completed.
+
+If the handler throws an error then the error will be caught, the
+finally block will be executed and the error will be re-thrown.
+
+Only one finally block may be specified per try block
+
+=back
+
+=head1 COMPATIBILITY
+
+L<Moose> exports a keyword called C<with> which clashes with Error's. This
+example returns a prototype mismatch error:
+
+    package MyTest;
+
+    use warnings;
+    use Moose;
+    use Error qw(:try);
+
+(Thanks to C<maik.hentsche@amd.com> for the report.).
+
+=head1 CLASS INTERFACE
+
+=head2 CONSTRUCTORS
+
+The C<Error> object is implemented as a HASH. This HASH is initialized
+with the arguments that are passed to it's constructor. The elements
+that are used by, or are retrievable by the C<Error> class are listed
+below, other classes may add to these.
+
+	-file
+	-line
+	-text
+	-value
+	-object
+
+If C<-file> or C<-line> are not specified in the constructor arguments
+then these will be initialized with the file name and line number where
+the constructor was called from.
+
+If the error is associated with an object then the object should be
+passed as the C<-object> argument. This will allow the C<Error> package
+to associate the error with the object.
+
+The C<Error> package remembers the last error created, and also the
+last error associated with a package. This could either be the last
+error created by a sub in that package, or the last error which passed
+an object blessed into that package as the C<-object> argument.
+
+=over 4
+
+=item Error->new()
+
+See the Error::Simple documentation.
+
+=item throw ( [ ARGS ] )
+
+Create a new C<Error> object and throw an error, which will be caught
+by a surrounding C<try> block, if there is one. Otherwise it will cause
+the program to exit.
+
+C<throw> may also be called on an existing error to re-throw it.
+
+=item with ( [ ARGS ] )
+
+Create a new C<Error> object and returns it. This is defined for
+syntactic sugar, eg
+
+    die with Some::Error ( ... );
+
+=item record ( [ ARGS ] )
+
+Create a new C<Error> object and returns it. This is defined for
+syntactic sugar, eg
+
+    record Some::Error ( ... )
+	and return;
+
+=back
+
+=head2 STATIC METHODS
+
+=over 4
+
+=item prior ( [ PACKAGE ] )
+
+Return the last error created, or the last error associated with
+C<PACKAGE>
+
+=item flush ( [ PACKAGE ] )
+
+Flush the last error created, or the last error associated with
+C<PACKAGE>.It is necessary to clear the error stack before exiting the
+package or uncaught errors generated using C<record> will be reported.
+
+     $Error->flush;
+
+=cut
+
+=back
+
+=head2 OBJECT METHODS
+
+=over 4
+
+=item stacktrace
+
+If the variable C<$Error::Debug> was non-zero when the error was
+created, then C<stacktrace> returns a string created by calling
+C<Carp::longmess>. If the variable was zero the C<stacktrace> returns
+the text of the error appended with the filename and line number of
+where the error was created, providing the text does not end with a
+newline.
+
+=item object
+
+The object this error was associated with
+
+=item file
+
+The file where the constructor of this error was called from
+
+=item line
+
+The line where the constructor of this error was called from
+
+=item text
+
+The text of the error
+
+=item $err->associate($obj)
+
+Associates an error with an object to allow error propagation. I.e:
+
+    $ber->encode(...) or
+        return Error->prior($ber)->associate($ldap);
+
+=back
+
+=head2 OVERLOAD METHODS
+
+=over 4
+
+=item stringify
+
+A method that converts the object into a string. This method may simply
+return the same as the C<text> method, or it may append more
+information. For example the file name and line number.
+
+By default this method returns the C<-text> argument that was passed to
+the constructor, or the string C<"Died"> if none was given.
+
+=item value
+
+A method that will return a value that can be associated with the
+error. For example if an error was created due to the failure of a
+system call, then this may return the numeric value of C<$!> at the
+time.
+
+By default this method returns the C<-value> argument that was passed
+to the constructor.
+
+=back
+
+=head1 PRE-DEFINED ERROR CLASSES
+
+=head2 Error::Simple
+
+This class can be used to hold simple error strings and values. It's
+constructor takes two arguments. The first is a text value, the second
+is a numeric value. These values are what will be returned by the
+overload methods.
+
+If the text value ends with C<at file line 1> as $@ strings do, then
+this information will be used to set the C<-file> and C<-line> arguments
+of the error object.
+
+This class is used internally if an eval'd block die's with an error
+that is a plain string. (Unless C<$Error::ObjectifyCallback> is modified)
+
+
+=head1 $Error::ObjectifyCallback
+
+This variable holds a reference to a subroutine that converts errors that
+are plain strings to objects. It is used by Error.pm to convert textual
+errors to objects, and can be overridden by the user.
+
+It accepts a single argument which is a hash reference to named parameters.
+Currently the only named parameter passed is C<'text'> which is the text
+of the error, but others may be available in the future.
+
+For example the following code will cause Error.pm to throw objects of the
+class MyError::Bar by default:
+
+    sub throw_MyError_Bar
+    {
+        my $args = shift;
+        my $err = MyError::Bar->new();
+        $err->{'MyBarText'} = $args->{'text'};
+        return $err;
+    }
+
+    {
+        local $Error::ObjectifyCallback = \&throw_MyError_Bar;
+
+        # Error handling here.
+    }
+
+=cut
+
+=head1 MESSAGE HANDLERS
+
+C<Error> also provides handlers to extend the output of the C<warn()> perl
+function, and to handle the printing of a thrown C<Error> that is not caught
+or otherwise handled. These are not installed by default, but are requested
+using the C<:warndie> tag in the C<use> line.
+
+ use Error qw( :warndie );
+
+These new error handlers are installed in C<$SIG{__WARN__}> and
+C<$SIG{__DIE__}>. If these handlers are already defined when the tag is
+imported, the old values are stored, and used during the new code. Thus, to
+arrange for custom handling of warnings and errors, you will need to perform
+something like the following:
+
+ BEGIN {
+   $SIG{__WARN__} = sub {
+     print STDERR "My special warning handler: $_[0]"
+   };
+ }
+
+ use Error qw( :warndie );
+
+Note that setting C<$SIG{__WARN__}> after the C<:warndie> tag has been
+imported will overwrite the handler that C<Error> provides. If this cannot be
+avoided, then the tag can be explicitly C<import>ed later
+
+ use Error;
+
+ $SIG{__WARN__} = ...;
+
+ import Error qw( :warndie );
+
+=head2 EXAMPLE
+
+The C<__DIE__> handler turns messages such as
+
+ Can't call method "foo" on an undefined value at examples/warndie.pl line 16.
+
+into
+
+ Unhandled perl error caught at toplevel:
+
+   Can't call method "foo" on an undefined value
+
+ Thrown from: examples/warndie.pl:16
+
+ Full stack trace:
+
+         main::inner('undef') called at examples/warndie.pl line 20
+         main::outer('undef') called at examples/warndie.pl line 23
+
+=cut
+
+=head1 SEE ALSO
+
+See L<Exception::Class> for a different module providing Object-Oriented
+exception handling, along with a convenient syntax for declaring hierarchies
+for them. It doesn't provide Error's syntactic sugar of C<try { ... }>,
+C<catch { ... }>, etc. which may be a good thing or a bad thing based
+on what you want. (Because Error's syntactic sugar tends to break.)
+
+L<Error::Exception> aims to combine L<Error> and L<Exception::Class>
+"with correct stringification".
+
+L<TryCatch> and L<Try::Tiny> are similar in concept to Error.pm only providing
+a syntax that hopefully breaks less.
+
+=head1 KNOWN BUGS
+
+None, but that does not mean there are not any.
+
+=head1 AUTHORS
+
+Graham Barr <gbarr@pobox.com>
+
+The code that inspired me to write this was originally written by
+Peter Seibel <peter@weblogic.com> and adapted by Jesse Glick
+<jglick@sig.bsh.com>.
+
+C<:warndie> handlers added by Paul Evans <leonerd@leonerd.org.uk>
+
+=head1 MAINTAINER
+
+Shlomi Fish, L<http://www.shlomifish.org/> .
+
+=head1 PAST MAINTAINERS
+
+Arun Kumar U <u_arunkumar@yahoo.com>
+
+=head1 COPYRIGHT
+
+Copyright (c) 1997-8  Graham Barr. All rights reserved.
+This program is free software; you can redistribute it and/or modify it
+under the same terms as Perl itself.
+
+=cut
diff --git a/third_party/git/perl/FromCPAN/Mail/Address.pm b/third_party/git/perl/FromCPAN/Mail/Address.pm
new file mode 100644
index 000000000000..683d490b2b0b
--- /dev/null
+++ b/third_party/git/perl/FromCPAN/Mail/Address.pm
@@ -0,0 +1,280 @@
+# Copyrights 1995-2018 by [Mark Overmeer].
+#  For other contributors see ChangeLog.
+# See the manual pages for details on the licensing terms.
+# Pod stripped from pm file by OODoc 2.02.
+# This code is part of the bundle MailTools.  Meta-POD processed with
+# OODoc into POD and HTML manual-pages.  See README.md for Copyright.
+# Licensed under the same terms as Perl itself.
+
+package Mail::Address;
+use vars '$VERSION';
+$VERSION = '2.20';
+
+use strict;
+
+use Carp;
+
+# use locale;   removed in version 1.78, because it causes taint problems
+
+sub Version { our $VERSION }
+
+
+
+# given a comment, attempt to extract a person's name
+sub _extract_name
+{   # This function can be called as method as well
+    my $self = @_ && ref $_[0] ? shift : undef;
+
+    local $_ = shift
+        or return '';
+
+    # Using encodings, too hard. See Mail::Message::Field::Full.
+    return '' if m/\=\?.*?\?\=/;
+
+    # trim whitespace
+    s/^\s+//;
+    s/\s+$//;
+    s/\s+/ /;
+
+    # Disregard numeric names (e.g. 123456.1234@compuserve.com)
+    return "" if /^[\d ]+$/;
+
+    s/^\((.*)\)$/$1/; # remove outermost parenthesis
+    s/^"(.*)"$/$1/;   # remove outer quotation marks
+    s/\(.*?\)//g;     # remove minimal embedded comments
+    s/\\//g;          # remove all escapes
+    s/^"(.*)"$/$1/;   # remove internal quotation marks
+    s/^([^\s]+) ?, ?(.*)$/$2 $1/; # reverse "Last, First M." if applicable
+    s/,.*//;
+
+    # Change casing only when the name contains only upper or only
+    # lower cased characters.
+    unless( m/[A-Z]/ && m/[a-z]/ )
+    {   # Set the case of the name to first char upper rest lower
+        s/\b(\w+)/\L\u$1/igo;  # Upcase first letter on name
+        s/\bMc(\w)/Mc\u$1/igo; # Scottish names such as 'McLeod'
+        s/\bo'(\w)/O'\u$1/igo; # Irish names such as 'O'Malley, O'Reilly'
+        s/\b(x*(ix)?v*(iv)?i*)\b/\U$1/igo; # Roman numerals, eg 'Level III Support'
+    }
+
+    # some cleanup
+    s/\[[^\]]*\]//g;
+    s/(^[\s'"]+|[\s'"]+$)//g;
+    s/\s{2,}/ /g;
+
+    $_;
+}
+
+sub _tokenise
+{   local $_ = join ',', @_;
+    my (@words,$snippet,$field);
+
+    s/\A\s+//;
+    s/[\r\n]+/ /g;
+
+    while ($_ ne '')
+    {   $field = '';
+        if(s/^\s*\(/(/ )    # (...)
+        {   my $depth = 0;
+
+     PAREN: while(s/^(\(([^\(\)\\]|\\.)*)//)
+            {   $field .= $1;
+                $depth++;
+                while(s/^(([^\(\)\\]|\\.)*\)\s*)//)
+                {   $field .= $1;
+                    last PAREN unless --$depth;
+	            $field .= $1 if s/^(([^\(\)\\]|\\.)+)//;
+                }
+            }
+
+            carp "Unmatched () '$field' '$_'"
+                if $depth;
+
+            $field =~ s/\s+\Z//;
+            push @words, $field;
+
+            next;
+        }
+
+        if( s/^("(?:[^"\\]+|\\.)*")\s*//       # "..."
+         || s/^(\[(?:[^\]\\]+|\\.)*\])\s*//    # [...]
+         || s/^([^\s()<>\@,;:\\".[\]]+)\s*//
+         || s/^([()<>\@,;:\\".[\]])\s*//
+          )
+        {   push @words, $1;
+            next;
+        }
+
+        croak "Unrecognised line: $_";
+    }
+
+    push @words, ",";
+    \@words;
+}
+
+sub _find_next
+{   my ($idx, $tokens, $len) = @_;
+
+    while($idx < $len)
+    {   my $c = $tokens->[$idx];
+        return $c if $c eq ',' || $c eq ';' || $c eq '<';
+        $idx++;
+    }
+
+    "";
+}
+
+sub _complete
+{   my ($class, $phrase, $address, $comment) = @_;
+
+    @$phrase || @$comment || @$address
+       or return undef;
+
+    my $o = $class->new(join(" ",@$phrase), join("",@$address), join(" ",@$comment));
+    @$phrase = @$address = @$comment = ();
+    $o;
+}
+
+#------------
+
+sub new(@)
+{   my $class = shift;
+    bless [@_], $class;
+}
+
+
+sub parse(@)
+{   my $class = shift;
+    my @line  = grep {defined} @_;
+    my $line  = join '', @line;
+
+    my (@phrase, @comment, @address, @objs);
+    my ($depth, $idx) = (0, 0);
+
+    my $tokens  = _tokenise @line;
+    my $len     = @$tokens;
+    my $next    = _find_next $idx, $tokens, $len;
+
+    local $_;
+    for(my $idx = 0; $idx < $len; $idx++)
+    {   $_ = $tokens->[$idx];
+
+        if(substr($_,0,1) eq '(') { push @comment, $_ }
+        elsif($_ eq '<')    { $depth++ }
+        elsif($_ eq '>')    { $depth-- if $depth }
+        elsif($_ eq ',' || $_ eq ';')
+        {   warn "Unmatched '<>' in $line" if $depth;
+            my $o = $class->_complete(\@phrase, \@address, \@comment);
+            push @objs, $o if defined $o;
+            $depth = 0;
+            $next = _find_next $idx+1, $tokens, $len;
+        }
+        elsif($depth)       { push @address, $_ }
+        elsif($next eq '<') { push @phrase,  $_ }
+        elsif( /^[.\@:;]$/ || !@address || $address[-1] =~ /^[.\@:;]$/ )
+        {   push @address, $_ }
+        else
+        {   warn "Unmatched '<>' in $line" if $depth;
+            my $o = $class->_complete(\@phrase, \@address, \@comment);
+            push @objs, $o if defined $o;
+            $depth = 0;
+            push @address, $_;
+        }
+    }
+    @objs;
+}
+
+#------------
+
+sub phrase  { shift->set_or_get(0, @_) }
+sub address { shift->set_or_get(1, @_) }
+sub comment { shift->set_or_get(2, @_) }
+
+sub set_or_get($)
+{   my ($self, $i) = (shift, shift);
+    @_ or return $self->[$i];
+
+    my $val = $self->[$i];
+    $self->[$i] = shift if @_;
+    $val;
+}
+
+
+my $atext = '[\-\w !#$%&\'*+/=?^`{|}~]';
+sub format
+{   my @addrs;
+
+    foreach (@_)
+    {   my ($phrase, $email, $comment) = @$_;
+        my @addr;
+
+        if(defined $phrase && length $phrase)
+        {   push @addr
+              , $phrase =~ /^(?:\s*$atext\s*)+$/o ? $phrase
+              : $phrase =~ /(?<!\\)"/             ? $phrase
+              :                                    qq("$phrase");
+
+            push @addr, "<$email>"
+                if defined $email && length $email;
+        }
+        elsif(defined $email && length $email)
+        {   push @addr, $email;
+        }
+
+        if(defined $comment && $comment =~ /\S/)
+        {   $comment =~ s/^\s*\(?/(/;
+            $comment =~ s/\)?\s*$/)/;
+        }
+
+        push @addr, $comment
+            if defined $comment && length $comment;
+
+        push @addrs, join(" ", @addr)
+            if @addr;
+    }
+
+    join ", ", @addrs;
+}
+
+#------------
+
+sub name
+{   my $self   = shift;
+    my $phrase = $self->phrase;
+    my $addr   = $self->address;
+
+    $phrase    = $self->comment
+        unless defined $phrase && length $phrase;
+
+    my $name   = $self->_extract_name($phrase);
+
+    # first.last@domain address
+    if($name eq '' && $addr =~ /([^\%\.\@_]+([\._][^\%\.\@_]+)+)[\@\%]/)
+    {   ($name  = $1) =~ s/[\._]+/ /g;
+	$name   = _extract_name $name;
+    }
+
+    if($name eq '' && $addr =~ m#/g=#i)    # X400 style address
+    {   my ($f) = $addr =~ m#g=([^/]*)#i;
+	my ($l) = $addr =~ m#s=([^/]*)#i;
+	$name   = _extract_name "$f $l";
+    }
+
+    length $name ? $name : undef;
+}
+
+
+sub host
+{   my $addr = shift->address || '';
+    my $i    = rindex $addr, '@';
+    $i >= 0 ? substr($addr, $i+1) : undef;
+}
+
+
+sub user
+{   my $addr = shift->address || '';
+    my $i    = rindex $addr, '@';
+    $i >= 0 ? substr($addr,0,$i) : $addr;
+}
+
+1;
diff --git a/third_party/git/perl/Git.pm b/third_party/git/perl/Git.pm
new file mode 100644
index 000000000000..62c472e0ce41
--- /dev/null
+++ b/third_party/git/perl/Git.pm
@@ -0,0 +1,1730 @@
+=head1 NAME
+
+Git - Perl interface to the Git version control system
+
+=cut
+
+
+package Git;
+
+use 5.008;
+use strict;
+use warnings;
+
+use File::Temp ();
+use File::Spec ();
+
+BEGIN {
+
+our ($VERSION, @ISA, @EXPORT, @EXPORT_OK);
+
+# Totally unstable API.
+$VERSION = '0.01';
+
+
+=head1 SYNOPSIS
+
+  use Git;
+
+  my $version = Git::command_oneline('version');
+
+  git_cmd_try { Git::command_noisy('update-server-info') }
+              '%s failed w/ code %d';
+
+  my $repo = Git->repository (Directory => '/srv/git/cogito.git');
+
+
+  my @revs = $repo->command('rev-list', '--since=last monday', '--all');
+
+  my ($fh, $c) = $repo->command_output_pipe('rev-list', '--since=last monday', '--all');
+  my $lastrev = <$fh>; chomp $lastrev;
+  $repo->command_close_pipe($fh, $c);
+
+  my $lastrev = $repo->command_oneline( [ 'rev-list', '--all' ],
+                                        STDERR => 0 );
+
+  my $sha1 = $repo->hash_and_insert_object('file.txt');
+  my $tempfile = tempfile();
+  my $size = $repo->cat_blob($sha1, $tempfile);
+
+=cut
+
+
+require Exporter;
+
+@ISA = qw(Exporter);
+
+@EXPORT = qw(git_cmd_try);
+
+# Methods which can be called as standalone functions as well:
+@EXPORT_OK = qw(command command_oneline command_noisy
+                command_output_pipe command_input_pipe command_close_pipe
+                command_bidi_pipe command_close_bidi_pipe
+                version exec_path html_path hash_object git_cmd_try
+                remote_refs prompt
+                get_tz_offset get_record
+                credential credential_read credential_write
+                temp_acquire temp_is_locked temp_release temp_reset temp_path
+                unquote_path);
+
+
+=head1 DESCRIPTION
+
+This module provides Perl scripts easy way to interface the Git version control
+system. The modules have an easy and well-tested way to call arbitrary Git
+commands; in the future, the interface will also provide specialized methods
+for doing easily operations which are not totally trivial to do over
+the generic command interface.
+
+While some commands can be executed outside of any context (e.g. 'version'
+or 'init'), most operations require a repository context, which in practice
+means getting an instance of the Git object using the repository() constructor.
+(In the future, we will also get a new_repository() constructor.) All commands
+called as methods of the object are then executed in the context of the
+repository.
+
+Part of the "repository state" is also information about path to the attached
+working copy (unless you work with a bare repository). You can also navigate
+inside of the working copy using the C<wc_chdir()> method. (Note that
+the repository object is self-contained and will not change working directory
+of your process.)
+
+TODO: In the future, we might also do
+
+	my $remoterepo = $repo->remote_repository (Name => 'cogito', Branch => 'master');
+	$remoterepo ||= Git->remote_repository ('http://git.or.cz/cogito.git/');
+	my @refs = $remoterepo->refs();
+
+Currently, the module merely wraps calls to external Git tools. In the future,
+it will provide a much faster way to interact with Git by linking directly
+to libgit. This should be completely opaque to the user, though (performance
+increase notwithstanding).
+
+=cut
+
+
+use Carp qw(carp croak); # but croak is bad - throw instead
+use Git::LoadCPAN::Error qw(:try);
+use Cwd qw(abs_path cwd);
+use IPC::Open2 qw(open2);
+use Fcntl qw(SEEK_SET SEEK_CUR);
+use Time::Local qw(timegm);
+}
+
+
+=head1 CONSTRUCTORS
+
+=over 4
+
+=item repository ( OPTIONS )
+
+=item repository ( DIRECTORY )
+
+=item repository ()
+
+Construct a new repository object.
+C<OPTIONS> are passed in a hash like fashion, using key and value pairs.
+Possible options are:
+
+B<Repository> - Path to the Git repository.
+
+B<WorkingCopy> - Path to the associated working copy; not strictly required
+as many commands will happily crunch on a bare repository.
+
+B<WorkingSubdir> - Subdirectory in the working copy to work inside.
+Just left undefined if you do not want to limit the scope of operations.
+
+B<Directory> - Path to the Git working directory in its usual setup.
+The C<.git> directory is searched in the directory and all the parent
+directories; if found, C<WorkingCopy> is set to the directory containing
+it and C<Repository> to the C<.git> directory itself. If no C<.git>
+directory was found, the C<Directory> is assumed to be a bare repository,
+C<Repository> is set to point at it and C<WorkingCopy> is left undefined.
+If the C<$GIT_DIR> environment variable is set, things behave as expected
+as well.
+
+You should not use both C<Directory> and either of C<Repository> and
+C<WorkingCopy> - the results of that are undefined.
+
+Alternatively, a directory path may be passed as a single scalar argument
+to the constructor; it is equivalent to setting only the C<Directory> option
+field.
+
+Calling the constructor with no options whatsoever is equivalent to
+calling it with C<< Directory => '.' >>. In general, if you are building
+a standard porcelain command, simply doing C<< Git->repository() >> should
+do the right thing and setup the object to reflect exactly where the user
+is right now.
+
+=cut
+
+sub repository {
+	my $class = shift;
+	my @args = @_;
+	my %opts = ();
+	my $self;
+
+	if (defined $args[0]) {
+		if ($#args % 2 != 1) {
+			# Not a hash.
+			$#args == 0 or throw Error::Simple("bad usage");
+			%opts = ( Directory => $args[0] );
+		} else {
+			%opts = @args;
+		}
+	}
+
+	if (not defined $opts{Repository} and not defined $opts{WorkingCopy}
+		and not defined $opts{Directory}) {
+		$opts{Directory} = '.';
+	}
+
+	if (defined $opts{Directory}) {
+		-d $opts{Directory} or throw Error::Simple("Directory not found: $opts{Directory} $!");
+
+		my $search = Git->repository(WorkingCopy => $opts{Directory});
+		my $dir;
+		try {
+			$dir = $search->command_oneline(['rev-parse', '--git-dir'],
+			                                STDERR => 0);
+		} catch Git::Error::Command with {
+			$dir = undef;
+		};
+
+		if ($dir) {
+			File::Spec->file_name_is_absolute($dir) or $dir = $opts{Directory} . '/' . $dir;
+			$opts{Repository} = abs_path($dir);
+
+			# If --git-dir went ok, this shouldn't die either.
+			my $prefix = $search->command_oneline('rev-parse', '--show-prefix');
+			$dir = abs_path($opts{Directory}) . '/';
+			if ($prefix) {
+				if (substr($dir, -length($prefix)) ne $prefix) {
+					throw Error::Simple("rev-parse confused me - $dir does not have trailing $prefix");
+				}
+				substr($dir, -length($prefix)) = '';
+			}
+			$opts{WorkingCopy} = $dir;
+			$opts{WorkingSubdir} = $prefix;
+
+		} else {
+			# A bare repository? Let's see...
+			$dir = $opts{Directory};
+
+			unless (-d "$dir/refs" and -d "$dir/objects" and -e "$dir/HEAD") {
+				# Mimic git-rev-parse --git-dir error message:
+				throw Error::Simple("fatal: Not a git repository: $dir");
+			}
+			my $search = Git->repository(Repository => $dir);
+			try {
+				$search->command('symbolic-ref', 'HEAD');
+			} catch Git::Error::Command with {
+				# Mimic git-rev-parse --git-dir error message:
+				throw Error::Simple("fatal: Not a git repository: $dir");
+			}
+
+			$opts{Repository} = abs_path($dir);
+		}
+
+		delete $opts{Directory};
+	}
+
+	$self = { opts => \%opts };
+	bless $self, $class;
+}
+
+=back
+
+=head1 METHODS
+
+=over 4
+
+=item command ( COMMAND [, ARGUMENTS... ] )
+
+=item command ( [ COMMAND, ARGUMENTS... ], { Opt => Val ... } )
+
+Execute the given Git C<COMMAND> (specify it without the 'git-'
+prefix), optionally with the specified extra C<ARGUMENTS>.
+
+The second more elaborate form can be used if you want to further adjust
+the command execution. Currently, only one option is supported:
+
+B<STDERR> - How to deal with the command's error output. By default (C<undef>)
+it is delivered to the caller's C<STDERR>. A false value (0 or '') will cause
+it to be thrown away. If you want to process it, you can get it in a filehandle
+you specify, but you must be extremely careful; if the error output is not
+very short and you want to read it in the same process as where you called
+C<command()>, you are set up for a nice deadlock!
+
+The method can be called without any instance or on a specified Git repository
+(in that case the command will be run in the repository context).
+
+In scalar context, it returns all the command output in a single string
+(verbatim).
+
+In array context, it returns an array containing lines printed to the
+command's stdout (without trailing newlines).
+
+In both cases, the command's stdin and stderr are the same as the caller's.
+
+=cut
+
+sub command {
+	my ($fh, $ctx) = command_output_pipe(@_);
+
+	if (not defined wantarray) {
+		# Nothing to pepper the possible exception with.
+		_cmd_close($ctx, $fh);
+
+	} elsif (not wantarray) {
+		local $/;
+		my $text = <$fh>;
+		try {
+			_cmd_close($ctx, $fh);
+		} catch Git::Error::Command with {
+			# Pepper with the output:
+			my $E = shift;
+			$E->{'-outputref'} = \$text;
+			throw $E;
+		};
+		return $text;
+
+	} else {
+		my @lines = <$fh>;
+		defined and chomp for @lines;
+		try {
+			_cmd_close($ctx, $fh);
+		} catch Git::Error::Command with {
+			my $E = shift;
+			$E->{'-outputref'} = \@lines;
+			throw $E;
+		};
+		return @lines;
+	}
+}
+
+
+=item command_oneline ( COMMAND [, ARGUMENTS... ] )
+
+=item command_oneline ( [ COMMAND, ARGUMENTS... ], { Opt => Val ... } )
+
+Execute the given C<COMMAND> in the same way as command()
+does but always return a scalar string containing the first line
+of the command's standard output.
+
+=cut
+
+sub command_oneline {
+	my ($fh, $ctx) = command_output_pipe(@_);
+
+	my $line = <$fh>;
+	defined $line and chomp $line;
+	try {
+		_cmd_close($ctx, $fh);
+	} catch Git::Error::Command with {
+		# Pepper with the output:
+		my $E = shift;
+		$E->{'-outputref'} = \$line;
+		throw $E;
+	};
+	return $line;
+}
+
+
+=item command_output_pipe ( COMMAND [, ARGUMENTS... ] )
+
+=item command_output_pipe ( [ COMMAND, ARGUMENTS... ], { Opt => Val ... } )
+
+Execute the given C<COMMAND> in the same way as command()
+does but return a pipe filehandle from which the command output can be
+read.
+
+The function can return C<($pipe, $ctx)> in array context.
+See C<command_close_pipe()> for details.
+
+=cut
+
+sub command_output_pipe {
+	_command_common_pipe('-|', @_);
+}
+
+
+=item command_input_pipe ( COMMAND [, ARGUMENTS... ] )
+
+=item command_input_pipe ( [ COMMAND, ARGUMENTS... ], { Opt => Val ... } )
+
+Execute the given C<COMMAND> in the same way as command_output_pipe()
+does but return an input pipe filehandle instead; the command output
+is not captured.
+
+The function can return C<($pipe, $ctx)> in array context.
+See C<command_close_pipe()> for details.
+
+=cut
+
+sub command_input_pipe {
+	_command_common_pipe('|-', @_);
+}
+
+
+=item command_close_pipe ( PIPE [, CTX ] )
+
+Close the C<PIPE> as returned from C<command_*_pipe()>, checking
+whether the command finished successfully. The optional C<CTX> argument
+is required if you want to see the command name in the error message,
+and it is the second value returned by C<command_*_pipe()> when
+called in array context. The call idiom is:
+
+	my ($fh, $ctx) = $r->command_output_pipe('status');
+	while (<$fh>) { ... }
+	$r->command_close_pipe($fh, $ctx);
+
+Note that you should not rely on whatever actually is in C<CTX>;
+currently it is simply the command name but in future the context might
+have more complicated structure.
+
+=cut
+
+sub command_close_pipe {
+	my ($self, $fh, $ctx) = _maybe_self(@_);
+	$ctx ||= '<unknown>';
+	_cmd_close($ctx, $fh);
+}
+
+=item command_bidi_pipe ( COMMAND [, ARGUMENTS... ] )
+
+Execute the given C<COMMAND> in the same way as command_output_pipe()
+does but return both an input pipe filehandle and an output pipe filehandle.
+
+The function will return C<($pid, $pipe_in, $pipe_out, $ctx)>.
+See C<command_close_bidi_pipe()> for details.
+
+=cut
+
+sub command_bidi_pipe {
+	my ($pid, $in, $out);
+	my ($self) = _maybe_self(@_);
+	local %ENV = %ENV;
+	my $cwd_save = undef;
+	if ($self) {
+		shift;
+		$cwd_save = cwd();
+		_setup_git_cmd_env($self);
+	}
+	$pid = open2($in, $out, 'git', @_);
+	chdir($cwd_save) if $cwd_save;
+	return ($pid, $in, $out, join(' ', @_));
+}
+
+=item command_close_bidi_pipe ( PID, PIPE_IN, PIPE_OUT [, CTX] )
+
+Close the C<PIPE_IN> and C<PIPE_OUT> as returned from C<command_bidi_pipe()>,
+checking whether the command finished successfully. The optional C<CTX>
+argument is required if you want to see the command name in the error message,
+and it is the fourth value returned by C<command_bidi_pipe()>.  The call idiom
+is:
+
+	my ($pid, $in, $out, $ctx) = $r->command_bidi_pipe('cat-file --batch-check');
+	print $out "000000000\n";
+	while (<$in>) { ... }
+	$r->command_close_bidi_pipe($pid, $in, $out, $ctx);
+
+Note that you should not rely on whatever actually is in C<CTX>;
+currently it is simply the command name but in future the context might
+have more complicated structure.
+
+C<PIPE_IN> and C<PIPE_OUT> may be C<undef> if they have been closed prior to
+calling this function.  This may be useful in a query-response type of
+commands where caller first writes a query and later reads response, eg:
+
+	my ($pid, $in, $out, $ctx) = $r->command_bidi_pipe('cat-file --batch-check');
+	print $out "000000000\n";
+	close $out;
+	while (<$in>) { ... }
+	$r->command_close_bidi_pipe($pid, $in, undef, $ctx);
+
+This idiom may prevent potential dead locks caused by data sent to the output
+pipe not being flushed and thus not reaching the executed command.
+
+=cut
+
+sub command_close_bidi_pipe {
+	local $?;
+	my ($self, $pid, $in, $out, $ctx) = _maybe_self(@_);
+	_cmd_close($ctx, (grep { defined } ($in, $out)));
+	waitpid $pid, 0;
+	if ($? >> 8) {
+		throw Git::Error::Command($ctx, $? >>8);
+	}
+}
+
+
+=item command_noisy ( COMMAND [, ARGUMENTS... ] )
+
+Execute the given C<COMMAND> in the same way as command() does but do not
+capture the command output - the standard output is not redirected and goes
+to the standard output of the caller application.
+
+While the method is called command_noisy(), you might want to as well use
+it for the most silent Git commands which you know will never pollute your
+stdout but you want to avoid the overhead of the pipe setup when calling them.
+
+The function returns only after the command has finished running.
+
+=cut
+
+sub command_noisy {
+	my ($self, $cmd, @args) = _maybe_self(@_);
+	_check_valid_cmd($cmd);
+
+	my $pid = fork;
+	if (not defined $pid) {
+		throw Error::Simple("fork failed: $!");
+	} elsif ($pid == 0) {
+		_cmd_exec($self, $cmd, @args);
+	}
+	if (waitpid($pid, 0) > 0 and $?>>8 != 0) {
+		throw Git::Error::Command(join(' ', $cmd, @args), $? >> 8);
+	}
+}
+
+
+=item version ()
+
+Return the Git version in use.
+
+=cut
+
+sub version {
+	my $verstr = command_oneline('--version');
+	$verstr =~ s/^git version //;
+	$verstr;
+}
+
+
+=item exec_path ()
+
+Return path to the Git sub-command executables (the same as
+C<git --exec-path>). Useful mostly only internally.
+
+=cut
+
+sub exec_path { command_oneline('--exec-path') }
+
+
+=item html_path ()
+
+Return path to the Git html documentation (the same as
+C<git --html-path>). Useful mostly only internally.
+
+=cut
+
+sub html_path { command_oneline('--html-path') }
+
+
+=item get_tz_offset ( TIME )
+
+Return the time zone offset from GMT in the form +/-HHMM where HH is
+the number of hours from GMT and MM is the number of minutes.  This is
+the equivalent of what strftime("%z", ...) would provide on a GNU
+platform.
+
+If TIME is not supplied, the current local time is used.
+
+=cut
+
+sub get_tz_offset {
+	# some systems don't handle or mishandle %z, so be creative.
+	my $t = shift || time;
+	my @t = localtime($t);
+	$t[5] += 1900;
+	my $gm = timegm(@t);
+	my $sign = qw( + + - )[ $gm <=> $t ];
+	return sprintf("%s%02d%02d", $sign, (gmtime(abs($t - $gm)))[2,1]);
+}
+
+=item get_record ( FILEHANDLE, INPUT_RECORD_SEPARATOR )
+
+Read one record from FILEHANDLE delimited by INPUT_RECORD_SEPARATOR,
+removing any trailing INPUT_RECORD_SEPARATOR.
+
+=cut
+
+sub get_record {
+	my ($fh, $rs) = @_;
+	local $/ = $rs;
+	my $rec = <$fh>;
+	chomp $rec if defined $rec;
+	$rec;
+}
+
+=item prompt ( PROMPT , ISPASSWORD  )
+
+Query user C<PROMPT> and return answer from user.
+
+Honours GIT_ASKPASS and SSH_ASKPASS environment variables for querying
+the user. If no *_ASKPASS variable is set or an error occoured,
+the terminal is tried as a fallback.
+If C<ISPASSWORD> is set and true, the terminal disables echo.
+
+=cut
+
+sub prompt {
+	my ($prompt, $isPassword) = @_;
+	my $ret;
+	if (exists $ENV{'GIT_ASKPASS'}) {
+		$ret = _prompt($ENV{'GIT_ASKPASS'}, $prompt);
+	}
+	if (!defined $ret && exists $ENV{'SSH_ASKPASS'}) {
+		$ret = _prompt($ENV{'SSH_ASKPASS'}, $prompt);
+	}
+	if (!defined $ret) {
+		print STDERR $prompt;
+		STDERR->flush;
+		if (defined $isPassword && $isPassword) {
+			require Term::ReadKey;
+			Term::ReadKey::ReadMode('noecho');
+			$ret = '';
+			while (defined(my $key = Term::ReadKey::ReadKey(0))) {
+				last if $key =~ /[\012\015]/; # \n\r
+				$ret .= $key;
+			}
+			Term::ReadKey::ReadMode('restore');
+			print STDERR "\n";
+			STDERR->flush;
+		} else {
+			chomp($ret = <STDIN>);
+		}
+	}
+	return $ret;
+}
+
+sub _prompt {
+	my ($askpass, $prompt) = @_;
+	return unless length $askpass;
+	$prompt =~ s/\n/ /g;
+	my $ret;
+	open my $fh, "-|", $askpass, $prompt or return;
+	$ret = <$fh>;
+	$ret =~ s/[\015\012]//g; # strip \r\n, chomp does not work on all systems (i.e. windows) as expected
+	close ($fh);
+	return $ret;
+}
+
+=item repo_path ()
+
+Return path to the git repository. Must be called on a repository instance.
+
+=cut
+
+sub repo_path { $_[0]->{opts}->{Repository} }
+
+
+=item wc_path ()
+
+Return path to the working copy. Must be called on a repository instance.
+
+=cut
+
+sub wc_path { $_[0]->{opts}->{WorkingCopy} }
+
+
+=item wc_subdir ()
+
+Return path to the subdirectory inside of a working copy. Must be called
+on a repository instance.
+
+=cut
+
+sub wc_subdir { $_[0]->{opts}->{WorkingSubdir} ||= '' }
+
+
+=item wc_chdir ( SUBDIR )
+
+Change the working copy subdirectory to work within. The C<SUBDIR> is
+relative to the working copy root directory (not the current subdirectory).
+Must be called on a repository instance attached to a working copy
+and the directory must exist.
+
+=cut
+
+sub wc_chdir {
+	my ($self, $subdir) = @_;
+	$self->wc_path()
+		or throw Error::Simple("bare repository");
+
+	-d $self->wc_path().'/'.$subdir
+		or throw Error::Simple("subdir not found: $subdir $!");
+	# Of course we will not "hold" the subdirectory so anyone
+	# can delete it now and we will never know. But at least we tried.
+
+	$self->{opts}->{WorkingSubdir} = $subdir;
+}
+
+
+=item config ( VARIABLE )
+
+Retrieve the configuration C<VARIABLE> in the same manner as C<config>
+does. In scalar context requires the variable to be set only one time
+(exception is thrown otherwise), in array context returns allows the
+variable to be set multiple times and returns all the values.
+
+=cut
+
+sub config {
+	return _config_common({}, @_);
+}
+
+
+=item config_bool ( VARIABLE )
+
+Retrieve the bool configuration C<VARIABLE>. The return value
+is usable as a boolean in perl (and C<undef> if it's not defined,
+of course).
+
+=cut
+
+sub config_bool {
+	my $val = scalar _config_common({'kind' => '--bool'}, @_);
+
+	# Do not rewrite this as return (defined $val && $val eq 'true')
+	# as some callers do care what kind of falsehood they receive.
+	if (!defined $val) {
+		return undef;
+	} else {
+		return $val eq 'true';
+	}
+}
+
+
+=item config_path ( VARIABLE )
+
+Retrieve the path configuration C<VARIABLE>. The return value
+is an expanded path or C<undef> if it's not defined.
+
+=cut
+
+sub config_path {
+	return _config_common({'kind' => '--path'}, @_);
+}
+
+
+=item config_int ( VARIABLE )
+
+Retrieve the integer configuration C<VARIABLE>. The return value
+is simple decimal number.  An optional value suffix of 'k', 'm',
+or 'g' in the config file will cause the value to be multiplied
+by 1024, 1048576 (1024^2), or 1073741824 (1024^3) prior to output.
+It would return C<undef> if configuration variable is not defined.
+
+=cut
+
+sub config_int {
+	return scalar _config_common({'kind' => '--int'}, @_);
+}
+
+# Common subroutine to implement bulk of what the config* family of methods
+# do. This currently wraps command('config') so it is not so fast.
+sub _config_common {
+	my ($opts) = shift @_;
+	my ($self, $var) = _maybe_self(@_);
+
+	try {
+		my @cmd = ('config', $opts->{'kind'} ? $opts->{'kind'} : ());
+		unshift @cmd, $self if $self;
+		if (wantarray) {
+			return command(@cmd, '--get-all', $var);
+		} else {
+			return command_oneline(@cmd, '--get', $var);
+		}
+	} catch Git::Error::Command with {
+		my $E = shift;
+		if ($E->value() == 1) {
+			# Key not found.
+			return;
+		} else {
+			throw $E;
+		}
+	};
+}
+
+=item get_colorbool ( NAME )
+
+Finds if color should be used for NAMEd operation from the configuration,
+and returns boolean (true for "use color", false for "do not use color").
+
+=cut
+
+sub get_colorbool {
+	my ($self, $var) = @_;
+	my $stdout_to_tty = (-t STDOUT) ? "true" : "false";
+	my $use_color = $self->command_oneline('config', '--get-colorbool',
+					       $var, $stdout_to_tty);
+	return ($use_color eq 'true');
+}
+
+=item get_color ( SLOT, COLOR )
+
+Finds color for SLOT from the configuration, while defaulting to COLOR,
+and returns the ANSI color escape sequence:
+
+	print $repo->get_color("color.interactive.prompt", "underline blue white");
+	print "some text";
+	print $repo->get_color("", "normal");
+
+=cut
+
+sub get_color {
+	my ($self, $slot, $default) = @_;
+	my $color = $self->command_oneline('config', '--get-color', $slot, $default);
+	if (!defined $color) {
+		$color = "";
+	}
+	return $color;
+}
+
+=item remote_refs ( REPOSITORY [, GROUPS [, REFGLOBS ] ] )
+
+This function returns a hashref of refs stored in a given remote repository.
+The hash is in the format C<refname =\> hash>. For tags, the C<refname> entry
+contains the tag object while a C<refname^{}> entry gives the tagged objects.
+
+C<REPOSITORY> has the same meaning as the appropriate C<git-ls-remote>
+argument; either a URL or a remote name (if called on a repository instance).
+C<GROUPS> is an optional arrayref that can contain 'tags' to return all the
+tags and/or 'heads' to return all the heads. C<REFGLOB> is an optional array
+of strings containing a shell-like glob to further limit the refs returned in
+the hash; the meaning is again the same as the appropriate C<git-ls-remote>
+argument.
+
+This function may or may not be called on a repository instance. In the former
+case, remote names as defined in the repository are recognized as repository
+specifiers.
+
+=cut
+
+sub remote_refs {
+	my ($self, $repo, $groups, $refglobs) = _maybe_self(@_);
+	my @args;
+	if (ref $groups eq 'ARRAY') {
+		foreach (@$groups) {
+			if ($_ eq 'heads') {
+				push (@args, '--heads');
+			} elsif ($_ eq 'tags') {
+				push (@args, '--tags');
+			} else {
+				# Ignore unknown groups for future
+				# compatibility
+			}
+		}
+	}
+	push (@args, $repo);
+	if (ref $refglobs eq 'ARRAY') {
+		push (@args, @$refglobs);
+	}
+
+	my @self = $self ? ($self) : (); # Ultra trickery
+	my ($fh, $ctx) = Git::command_output_pipe(@self, 'ls-remote', @args);
+	my %refs;
+	while (<$fh>) {
+		chomp;
+		my ($hash, $ref) = split(/\t/, $_, 2);
+		$refs{$ref} = $hash;
+	}
+	Git::command_close_pipe(@self, $fh, $ctx);
+	return \%refs;
+}
+
+
+=item ident ( TYPE | IDENTSTR )
+
+=item ident_person ( TYPE | IDENTSTR | IDENTARRAY )
+
+This suite of functions retrieves and parses ident information, as stored
+in the commit and tag objects or produced by C<var GIT_type_IDENT> (thus
+C<TYPE> can be either I<author> or I<committer>; case is insignificant).
+
+The C<ident> method retrieves the ident information from C<git var>
+and either returns it as a scalar string or as an array with the fields parsed.
+Alternatively, it can take a prepared ident string (e.g. from the commit
+object) and just parse it.
+
+C<ident_person> returns the person part of the ident - name and email;
+it can take the same arguments as C<ident> or the array returned by C<ident>.
+
+The synopsis is like:
+
+	my ($name, $email, $time_tz) = ident('author');
+	"$name <$email>" eq ident_person('author');
+	"$name <$email>" eq ident_person($name);
+	$time_tz =~ /^\d+ [+-]\d{4}$/;
+
+=cut
+
+sub ident {
+	my ($self, $type) = _maybe_self(@_);
+	my $identstr;
+	if (lc $type eq lc 'committer' or lc $type eq lc 'author') {
+		my @cmd = ('var', 'GIT_'.uc($type).'_IDENT');
+		unshift @cmd, $self if $self;
+		$identstr = command_oneline(@cmd);
+	} else {
+		$identstr = $type;
+	}
+	if (wantarray) {
+		return $identstr =~ /^(.*) <(.*)> (\d+ [+-]\d{4})$/;
+	} else {
+		return $identstr;
+	}
+}
+
+sub ident_person {
+	my ($self, @ident) = _maybe_self(@_);
+	$#ident == 0 and @ident = $self ? $self->ident($ident[0]) : ident($ident[0]);
+	return "$ident[0] <$ident[1]>";
+}
+
+=item hash_object ( TYPE, FILENAME )
+
+Compute the SHA1 object id of the given C<FILENAME> considering it is
+of the C<TYPE> object type (C<blob>, C<commit>, C<tree>).
+
+The method can be called without any instance or on a specified Git repository,
+it makes zero difference.
+
+The function returns the SHA1 hash.
+
+=cut
+
+# TODO: Support for passing FILEHANDLE instead of FILENAME
+sub hash_object {
+	my ($self, $type, $file) = _maybe_self(@_);
+	command_oneline('hash-object', '-t', $type, $file);
+}
+
+
+=item hash_and_insert_object ( FILENAME )
+
+Compute the SHA1 object id of the given C<FILENAME> and add the object to the
+object database.
+
+The function returns the SHA1 hash.
+
+=cut
+
+# TODO: Support for passing FILEHANDLE instead of FILENAME
+sub hash_and_insert_object {
+	my ($self, $filename) = @_;
+
+	carp "Bad filename \"$filename\"" if $filename =~ /[\r\n]/;
+
+	$self->_open_hash_and_insert_object_if_needed();
+	my ($in, $out) = ($self->{hash_object_in}, $self->{hash_object_out});
+
+	unless (print $out $filename, "\n") {
+		$self->_close_hash_and_insert_object();
+		throw Error::Simple("out pipe went bad");
+	}
+
+	chomp(my $hash = <$in>);
+	unless (defined($hash)) {
+		$self->_close_hash_and_insert_object();
+		throw Error::Simple("in pipe went bad");
+	}
+
+	return $hash;
+}
+
+sub _open_hash_and_insert_object_if_needed {
+	my ($self) = @_;
+
+	return if defined($self->{hash_object_pid});
+
+	($self->{hash_object_pid}, $self->{hash_object_in},
+	 $self->{hash_object_out}, $self->{hash_object_ctx}) =
+		$self->command_bidi_pipe(qw(hash-object -w --stdin-paths --no-filters));
+}
+
+sub _close_hash_and_insert_object {
+	my ($self) = @_;
+
+	return unless defined($self->{hash_object_pid});
+
+	my @vars = map { 'hash_object_' . $_ } qw(pid in out ctx);
+
+	command_close_bidi_pipe(@$self{@vars});
+	delete @$self{@vars};
+}
+
+=item cat_blob ( SHA1, FILEHANDLE )
+
+Prints the contents of the blob identified by C<SHA1> to C<FILEHANDLE> and
+returns the number of bytes printed.
+
+=cut
+
+sub cat_blob {
+	my ($self, $sha1, $fh) = @_;
+
+	$self->_open_cat_blob_if_needed();
+	my ($in, $out) = ($self->{cat_blob_in}, $self->{cat_blob_out});
+
+	unless (print $out $sha1, "\n") {
+		$self->_close_cat_blob();
+		throw Error::Simple("out pipe went bad");
+	}
+
+	my $description = <$in>;
+	if ($description =~ / missing$/) {
+		carp "$sha1 doesn't exist in the repository";
+		return -1;
+	}
+
+	if ($description !~ /^[0-9a-fA-F]{40}(?:[0-9a-fA-F]{24})? \S+ (\d+)$/) {
+		carp "Unexpected result returned from git cat-file";
+		return -1;
+	}
+
+	my $size = $1;
+
+	my $blob;
+	my $bytesLeft = $size;
+
+	while (1) {
+		last unless $bytesLeft;
+
+		my $bytesToRead = $bytesLeft < 1024 ? $bytesLeft : 1024;
+		my $read = read($in, $blob, $bytesToRead);
+		unless (defined($read)) {
+			$self->_close_cat_blob();
+			throw Error::Simple("in pipe went bad");
+		}
+		unless (print $fh $blob) {
+			$self->_close_cat_blob();
+			throw Error::Simple("couldn't write to passed in filehandle");
+		}
+		$bytesLeft -= $read;
+	}
+
+	# Skip past the trailing newline.
+	my $newline;
+	my $read = read($in, $newline, 1);
+	unless (defined($read)) {
+		$self->_close_cat_blob();
+		throw Error::Simple("in pipe went bad");
+	}
+	unless ($read == 1 && $newline eq "\n") {
+		$self->_close_cat_blob();
+		throw Error::Simple("didn't find newline after blob");
+	}
+
+	return $size;
+}
+
+sub _open_cat_blob_if_needed {
+	my ($self) = @_;
+
+	return if defined($self->{cat_blob_pid});
+
+	($self->{cat_blob_pid}, $self->{cat_blob_in},
+	 $self->{cat_blob_out}, $self->{cat_blob_ctx}) =
+		$self->command_bidi_pipe(qw(cat-file --batch));
+}
+
+sub _close_cat_blob {
+	my ($self) = @_;
+
+	return unless defined($self->{cat_blob_pid});
+
+	my @vars = map { 'cat_blob_' . $_ } qw(pid in out ctx);
+
+	command_close_bidi_pipe(@$self{@vars});
+	delete @$self{@vars};
+}
+
+
+=item credential_read( FILEHANDLE )
+
+Reads credential key-value pairs from C<FILEHANDLE>.  Reading stops at EOF or
+when an empty line is encountered.  Each line must be of the form C<key=value>
+with a non-empty key.  Function returns hash with all read values.  Any white
+space (other than new-line character) is preserved.
+
+=cut
+
+sub credential_read {
+	my ($self, $reader) = _maybe_self(@_);
+	my %credential;
+	while (<$reader>) {
+		chomp;
+		if ($_ eq '') {
+			last;
+		} elsif (!/^([^=]+)=(.*)$/) {
+			throw Error::Simple("unable to parse git credential data:\n$_");
+		}
+		$credential{$1} = $2;
+	}
+	return %credential;
+}
+
+=item credential_write( FILEHANDLE, CREDENTIAL_HASHREF )
+
+Writes credential key-value pairs from hash referenced by
+C<CREDENTIAL_HASHREF> to C<FILEHANDLE>.  Keys and values cannot contain
+new-lines or NUL bytes characters, and key cannot contain equal signs nor be
+empty (if they do Error::Simple is thrown).  Any white space is preserved.  If
+value for a key is C<undef>, it will be skipped.
+
+If C<'url'> key exists it will be written first.  (All the other key-value
+pairs are written in sorted order but you should not depend on that).  Once
+all lines are written, an empty line is printed.
+
+=cut
+
+sub credential_write {
+	my ($self, $writer, $credential) = _maybe_self(@_);
+	my ($key, $value);
+
+	# Check if $credential is valid prior to writing anything
+	while (($key, $value) = each %$credential) {
+		if (!defined $key || !length $key) {
+			throw Error::Simple("credential key empty or undefined");
+		} elsif ($key =~ /[=\n\0]/) {
+			throw Error::Simple("credential key contains invalid characters: $key");
+		} elsif (defined $value && $value =~ /[\n\0]/) {
+			throw Error::Simple("credential value for key=$key contains invalid characters: $value");
+		}
+	}
+
+	for $key (sort {
+		# url overwrites other fields, so it must come first
+		return -1 if $a eq 'url';
+		return  1 if $b eq 'url';
+		return $a cmp $b;
+	} keys %$credential) {
+		if (defined $credential->{$key}) {
+			print $writer $key, '=', $credential->{$key}, "\n";
+		}
+	}
+	print $writer "\n";
+}
+
+sub _credential_run {
+	my ($self, $credential, $op) = _maybe_self(@_);
+	my ($pid, $reader, $writer, $ctx) = command_bidi_pipe('credential', $op);
+
+	credential_write $writer, $credential;
+	close $writer;
+
+	if ($op eq "fill") {
+		%$credential = credential_read $reader;
+	}
+	if (<$reader>) {
+		throw Error::Simple("unexpected output from git credential $op response:\n$_\n");
+	}
+
+	command_close_bidi_pipe($pid, $reader, undef, $ctx);
+}
+
+=item credential( CREDENTIAL_HASHREF [, OPERATION ] )
+
+=item credential( CREDENTIAL_HASHREF, CODE )
+
+Executes C<git credential> for a given set of credentials and specified
+operation.  In both forms C<CREDENTIAL_HASHREF> needs to be a reference to
+a hash which stores credentials.  Under certain conditions the hash can
+change.
+
+In the first form, C<OPERATION> can be C<'fill'>, C<'approve'> or C<'reject'>,
+and function will execute corresponding C<git credential> sub-command.  If
+it's omitted C<'fill'> is assumed.  In case of C<'fill'> the values stored in
+C<CREDENTIAL_HASHREF> will be changed to the ones returned by the C<git
+credential fill> command.  The usual usage would look something like:
+
+	my %cred = (
+		'protocol' => 'https',
+		'host' => 'example.com',
+		'username' => 'bob'
+	);
+	Git::credential \%cred;
+	if (try_to_authenticate($cred{'username'}, $cred{'password'})) {
+		Git::credential \%cred, 'approve';
+		... do more stuff ...
+	} else {
+		Git::credential \%cred, 'reject';
+	}
+
+In the second form, C<CODE> needs to be a reference to a subroutine.  The
+function will execute C<git credential fill> to fill the provided credential
+hash, then call C<CODE> with C<CREDENTIAL_HASHREF> as the sole argument.  If
+C<CODE>'s return value is defined, the function will execute C<git credential
+approve> (if return value yields true) or C<git credential reject> (if return
+value is false).  If the return value is undef, nothing at all is executed;
+this is useful, for example, if the credential could neither be verified nor
+rejected due to an unrelated network error.  The return value is the same as
+what C<CODE> returns.  With this form, the usage might look as follows:
+
+	if (Git::credential {
+		'protocol' => 'https',
+		'host' => 'example.com',
+		'username' => 'bob'
+	}, sub {
+		my $cred = shift;
+		return !!try_to_authenticate($cred->{'username'},
+		                             $cred->{'password'});
+	}) {
+		... do more stuff ...
+	}
+
+=cut
+
+sub credential {
+	my ($self, $credential, $op_or_code) = (_maybe_self(@_), 'fill');
+
+	if ('CODE' eq ref $op_or_code) {
+		_credential_run $credential, 'fill';
+		my $ret = $op_or_code->($credential);
+		if (defined $ret) {
+			_credential_run $credential, $ret ? 'approve' : 'reject';
+		}
+		return $ret;
+	} else {
+		_credential_run $credential, $op_or_code;
+	}
+}
+
+{ # %TEMP_* Lexical Context
+
+my (%TEMP_FILEMAP, %TEMP_FILES);
+
+=item temp_acquire ( NAME )
+
+Attempts to retrieve the temporary file mapped to the string C<NAME>. If an
+associated temp file has not been created this session or was closed, it is
+created, cached, and set for autoflush and binmode.
+
+Internally locks the file mapped to C<NAME>. This lock must be released with
+C<temp_release()> when the temp file is no longer needed. Subsequent attempts
+to retrieve temporary files mapped to the same C<NAME> while still locked will
+cause an error. This locking mechanism provides a weak guarantee and is not
+threadsafe. It does provide some error checking to help prevent temp file refs
+writing over one another.
+
+In general, the L<File::Handle> returned should not be closed by consumers as
+it defeats the purpose of this caching mechanism. If you need to close the temp
+file handle, then you should use L<File::Temp> or another temp file faculty
+directly. If a handle is closed and then requested again, then a warning will
+issue.
+
+=cut
+
+sub temp_acquire {
+	my $temp_fd = _temp_cache(@_);
+
+	$TEMP_FILES{$temp_fd}{locked} = 1;
+	$temp_fd;
+}
+
+=item temp_is_locked ( NAME )
+
+Returns true if the internal lock created by a previous C<temp_acquire()>
+call with C<NAME> is still in effect.
+
+When temp_acquire is called on a C<NAME>, it internally locks the temporary
+file mapped to C<NAME>.  That lock will not be released until C<temp_release()>
+is called with either the original C<NAME> or the L<File::Handle> that was
+returned from the original call to temp_acquire.
+
+Subsequent attempts to call C<temp_acquire()> with the same C<NAME> will fail
+unless there has been an intervening C<temp_release()> call for that C<NAME>
+(or its corresponding L<File::Handle> that was returned by the original
+C<temp_acquire()> call).
+
+If true is returned by C<temp_is_locked()> for a C<NAME>, an attempt to
+C<temp_acquire()> the same C<NAME> will cause an error unless
+C<temp_release> is first called on that C<NAME> (or its corresponding
+L<File::Handle> that was returned by the original C<temp_acquire()> call).
+
+=cut
+
+sub temp_is_locked {
+	my ($self, $name) = _maybe_self(@_);
+	my $temp_fd = \$TEMP_FILEMAP{$name};
+
+	defined $$temp_fd && $$temp_fd->opened && $TEMP_FILES{$$temp_fd}{locked};
+}
+
+=item temp_release ( NAME )
+
+=item temp_release ( FILEHANDLE )
+
+Releases a lock acquired through C<temp_acquire()>. Can be called either with
+the C<NAME> mapping used when acquiring the temp file or with the C<FILEHANDLE>
+referencing a locked temp file.
+
+Warns if an attempt is made to release a file that is not locked.
+
+The temp file will be truncated before being released. This can help to reduce
+disk I/O where the system is smart enough to detect the truncation while data
+is in the output buffers. Beware that after the temp file is released and
+truncated, any operations on that file may fail miserably until it is
+re-acquired. All contents are lost between each release and acquire mapped to
+the same string.
+
+=cut
+
+sub temp_release {
+	my ($self, $temp_fd, $trunc) = _maybe_self(@_);
+
+	if (exists $TEMP_FILEMAP{$temp_fd}) {
+		$temp_fd = $TEMP_FILES{$temp_fd};
+	}
+	unless ($TEMP_FILES{$temp_fd}{locked}) {
+		carp "Attempt to release temp file '",
+			$temp_fd, "' that has not been locked";
+	}
+	temp_reset($temp_fd) if $trunc and $temp_fd->opened;
+
+	$TEMP_FILES{$temp_fd}{locked} = 0;
+	undef;
+}
+
+sub _temp_cache {
+	my ($self, $name) = _maybe_self(@_);
+
+	my $temp_fd = \$TEMP_FILEMAP{$name};
+	if (defined $$temp_fd and $$temp_fd->opened) {
+		if ($TEMP_FILES{$$temp_fd}{locked}) {
+			throw Error::Simple("Temp file with moniker '" .
+				$name . "' already in use");
+		}
+	} else {
+		if (defined $$temp_fd) {
+			# then we're here because of a closed handle.
+			carp "Temp file '", $name,
+				"' was closed. Opening replacement.";
+		}
+		my $fname;
+
+		my $tmpdir;
+		if (defined $self) {
+			$tmpdir = $self->repo_path();
+		}
+
+		my $n = $name;
+		$n =~ s/\W/_/g; # no strange chars
+
+		($$temp_fd, $fname) = File::Temp::tempfile(
+			"Git_${n}_XXXXXX", UNLINK => 1, DIR => $tmpdir,
+			) or throw Error::Simple("couldn't open new temp file");
+
+		$$temp_fd->autoflush;
+		binmode $$temp_fd;
+		$TEMP_FILES{$$temp_fd}{fname} = $fname;
+	}
+	$$temp_fd;
+}
+
+=item temp_reset ( FILEHANDLE )
+
+Truncates and resets the position of the C<FILEHANDLE>.
+
+=cut
+
+sub temp_reset {
+	my ($self, $temp_fd) = _maybe_self(@_);
+
+	truncate $temp_fd, 0
+		or throw Error::Simple("couldn't truncate file");
+	sysseek($temp_fd, 0, SEEK_SET) and seek($temp_fd, 0, SEEK_SET)
+		or throw Error::Simple("couldn't seek to beginning of file");
+	sysseek($temp_fd, 0, SEEK_CUR) == 0 and tell($temp_fd) == 0
+		or throw Error::Simple("expected file position to be reset");
+}
+
+=item temp_path ( NAME )
+
+=item temp_path ( FILEHANDLE )
+
+Returns the filename associated with the given tempfile.
+
+=cut
+
+sub temp_path {
+	my ($self, $temp_fd) = _maybe_self(@_);
+
+	if (exists $TEMP_FILEMAP{$temp_fd}) {
+		$temp_fd = $TEMP_FILEMAP{$temp_fd};
+	}
+	$TEMP_FILES{$temp_fd}{fname};
+}
+
+sub END {
+	unlink values %TEMP_FILEMAP if %TEMP_FILEMAP;
+}
+
+} # %TEMP_* Lexical Context
+
+=item prefix_lines ( PREFIX, STRING [, STRING... ])
+
+Prefixes lines in C<STRING> with C<PREFIX>.
+
+=cut
+
+sub prefix_lines {
+	my $prefix = shift;
+	my $string = join("\n", @_);
+	$string =~ s/^/$prefix/mg;
+	return $string;
+}
+
+=item unquote_path ( PATH )
+
+Unquote a quoted path containing c-escapes as returned by ls-files etc.
+when not using -z or when parsing the output of diff -u.
+
+=cut
+
+{
+	my %cquote_map = (
+		"a" => chr(7),
+		"b" => chr(8),
+		"t" => chr(9),
+		"n" => chr(10),
+		"v" => chr(11),
+		"f" => chr(12),
+		"r" => chr(13),
+		"\\" => "\\",
+		"\042" => "\042",
+	);
+
+	sub unquote_path {
+		local ($_) = @_;
+		my ($retval, $remainder);
+		if (!/^\042(.*)\042$/) {
+			return $_;
+		}
+		($_, $retval) = ($1, "");
+		while (/^([^\\]*)\\(.*)$/) {
+			$remainder = $2;
+			$retval .= $1;
+			for ($remainder) {
+				if (/^([0-3][0-7][0-7])(.*)$/) {
+					$retval .= chr(oct($1));
+					$_ = $2;
+					last;
+				}
+				if (/^([\\\042abtnvfr])(.*)$/) {
+					$retval .= $cquote_map{$1};
+					$_ = $2;
+					last;
+				}
+				# This is malformed
+				throw Error::Simple("invalid quoted path $_[0]");
+			}
+			$_ = $remainder;
+		}
+		$retval .= $_;
+		return $retval;
+	}
+}
+
+=item get_comment_line_char ( )
+
+Gets the core.commentchar configuration value.
+The value falls-back to '#' if core.commentchar is set to 'auto'.
+
+=cut
+
+sub get_comment_line_char {
+	my $comment_line_char = config("core.commentchar") || '#';
+	$comment_line_char = '#' if ($comment_line_char eq 'auto');
+	$comment_line_char = '#' if (length($comment_line_char) != 1);
+	return $comment_line_char;
+}
+
+=item comment_lines ( STRING [, STRING... ])
+
+Comments lines following core.commentchar configuration.
+
+=cut
+
+sub comment_lines {
+	my $comment_line_char = get_comment_line_char;
+	return prefix_lines("$comment_line_char ", @_);
+}
+
+=back
+
+=head1 ERROR HANDLING
+
+All functions are supposed to throw Perl exceptions in case of errors.
+See the L<Error> module on how to catch those. Most exceptions are mere
+L<Error::Simple> instances.
+
+However, the C<command()>, C<command_oneline()> and C<command_noisy()>
+functions suite can throw C<Git::Error::Command> exceptions as well: those are
+thrown when the external command returns an error code and contain the error
+code as well as access to the captured command's output. The exception class
+provides the usual C<stringify> and C<value> (command's exit code) methods and
+in addition also a C<cmd_output> method that returns either an array or a
+string with the captured command output (depending on the original function
+call context; C<command_noisy()> returns C<undef>) and $<cmdline> which
+returns the command and its arguments (but without proper quoting).
+
+Note that the C<command_*_pipe()> functions cannot throw this exception since
+it has no idea whether the command failed or not. You will only find out
+at the time you C<close> the pipe; if you want to have that automated,
+use C<command_close_pipe()>, which can throw the exception.
+
+=cut
+
+{
+	package Git::Error::Command;
+
+	@Git::Error::Command::ISA = qw(Error);
+
+	sub new {
+		my $self = shift;
+		my $cmdline = '' . shift;
+		my $value = 0 + shift;
+		my $outputref = shift;
+		my(@args) = ();
+
+		local $Error::Depth = $Error::Depth + 1;
+
+		push(@args, '-cmdline', $cmdline);
+		push(@args, '-value', $value);
+		push(@args, '-outputref', $outputref);
+
+		$self->SUPER::new(-text => 'command returned error', @args);
+	}
+
+	sub stringify {
+		my $self = shift;
+		my $text = $self->SUPER::stringify;
+		$self->cmdline() . ': ' . $text . ': ' . $self->value() . "\n";
+	}
+
+	sub cmdline {
+		my $self = shift;
+		$self->{'-cmdline'};
+	}
+
+	sub cmd_output {
+		my $self = shift;
+		my $ref = $self->{'-outputref'};
+		defined $ref or undef;
+		if (ref $ref eq 'ARRAY') {
+			return @$ref;
+		} else { # SCALAR
+			return $$ref;
+		}
+	}
+}
+
+=over 4
+
+=item git_cmd_try { CODE } ERRMSG
+
+This magical statement will automatically catch any C<Git::Error::Command>
+exceptions thrown by C<CODE> and make your program die with C<ERRMSG>
+on its lips; the message will have %s substituted for the command line
+and %d for the exit status. This statement is useful mostly for producing
+more user-friendly error messages.
+
+In case of no exception caught the statement returns C<CODE>'s return value.
+
+Note that this is the only auto-exported function.
+
+=cut
+
+sub git_cmd_try(&$) {
+	my ($code, $errmsg) = @_;
+	my @result;
+	my $err;
+	my $array = wantarray;
+	try {
+		if ($array) {
+			@result = &$code;
+		} else {
+			$result[0] = &$code;
+		}
+	} catch Git::Error::Command with {
+		my $E = shift;
+		$err = $errmsg;
+		$err =~ s/\%s/$E->cmdline()/ge;
+		$err =~ s/\%d/$E->value()/ge;
+		# We can't croak here since Error.pm would mangle
+		# that to Error::Simple.
+	};
+	$err and croak $err;
+	return $array ? @result : $result[0];
+}
+
+
+=back
+
+=head1 COPYRIGHT
+
+Copyright 2006 by Petr Baudis E<lt>pasky@suse.czE<gt>.
+
+This module is free software; it may be used, copied, modified
+and distributed under the terms of the GNU General Public Licence,
+either version 2, or (at your option) any later version.
+
+=cut
+
+
+# Take raw method argument list and return ($obj, @args) in case
+# the method was called upon an instance and (undef, @args) if
+# it was called directly.
+sub _maybe_self {
+	UNIVERSAL::isa($_[0], 'Git') ? @_ : (undef, @_);
+}
+
+# Check if the command id is something reasonable.
+sub _check_valid_cmd {
+	my ($cmd) = @_;
+	$cmd =~ /^[a-z0-9A-Z_-]+$/ or throw Error::Simple("bad command: $cmd");
+}
+
+# Common backend for the pipe creators.
+sub _command_common_pipe {
+	my $direction = shift;
+	my ($self, @p) = _maybe_self(@_);
+	my (%opts, $cmd, @args);
+	if (ref $p[0]) {
+		($cmd, @args) = @{shift @p};
+		%opts = ref $p[0] ? %{$p[0]} : @p;
+	} else {
+		($cmd, @args) = @p;
+	}
+	_check_valid_cmd($cmd);
+
+	my $fh;
+	if ($^O eq 'MSWin32') {
+		# ActiveState Perl
+		#defined $opts{STDERR} and
+		#	warn 'ignoring STDERR option - running w/ ActiveState';
+		$direction eq '-|' or
+			die 'input pipe for ActiveState not implemented';
+		# the strange construction with *ACPIPE is just to
+		# explain the tie below that we want to bind to
+		# a handle class, not scalar. It is not known if
+		# it is something specific to ActiveState Perl or
+		# just a Perl quirk.
+		tie (*ACPIPE, 'Git::activestate_pipe', $cmd, @args);
+		$fh = *ACPIPE;
+
+	} else {
+		my $pid = open($fh, $direction);
+		if (not defined $pid) {
+			throw Error::Simple("open failed: $!");
+		} elsif ($pid == 0) {
+			if ($opts{STDERR}) {
+				open (STDERR, '>&', $opts{STDERR})
+					or die "dup failed: $!";
+			} elsif (defined $opts{STDERR}) {
+				open (STDERR, '>', '/dev/null')
+					or die "opening /dev/null failed: $!";
+			}
+			_cmd_exec($self, $cmd, @args);
+		}
+	}
+	return wantarray ? ($fh, join(' ', $cmd, @args)) : $fh;
+}
+
+# When already in the subprocess, set up the appropriate state
+# for the given repository and execute the git command.
+sub _cmd_exec {
+	my ($self, @args) = @_;
+	_setup_git_cmd_env($self);
+	_execv_git_cmd(@args);
+	die qq[exec "@args" failed: $!];
+}
+
+# set up the appropriate state for git command
+sub _setup_git_cmd_env {
+	my $self = shift;
+	if ($self) {
+		$self->repo_path() and $ENV{'GIT_DIR'} = $self->repo_path();
+		$self->repo_path() and $self->wc_path()
+			and $ENV{'GIT_WORK_TREE'} = $self->wc_path();
+		$self->wc_path() and chdir($self->wc_path());
+		$self->wc_subdir() and chdir($self->wc_subdir());
+	}
+}
+
+# Execute the given Git command ($_[0]) with arguments ($_[1..])
+# by searching for it at proper places.
+sub _execv_git_cmd { exec('git', @_); }
+
+# Close pipe to a subprocess.
+sub _cmd_close {
+	my $ctx = shift @_;
+	foreach my $fh (@_) {
+		if (close $fh) {
+			# nop
+		} elsif ($!) {
+			# It's just close, no point in fatalities
+			carp "error closing pipe: $!";
+		} elsif ($? >> 8) {
+			# The caller should pepper this.
+			throw Git::Error::Command($ctx, $? >> 8);
+		}
+		# else we might e.g. closed a live stream; the command
+		# dying of SIGPIPE would drive us here.
+	}
+}
+
+
+sub DESTROY {
+	my ($self) = @_;
+	$self->_close_hash_and_insert_object();
+	$self->_close_cat_blob();
+}
+
+
+# Pipe implementation for ActiveState Perl.
+
+package Git::activestate_pipe;
+
+sub TIEHANDLE {
+	my ($class, @params) = @_;
+	# FIXME: This is probably horrible idea and the thing will explode
+	# at the moment you give it arguments that require some quoting,
+	# but I have no ActiveState clue... --pasky
+	# Let's just hope ActiveState Perl does at least the quoting
+	# correctly.
+	my @data = qx{git @params};
+	bless { i => 0, data => \@data }, $class;
+}
+
+sub READLINE {
+	my $self = shift;
+	if ($self->{i} >= scalar @{$self->{data}}) {
+		return undef;
+	}
+	my $i = $self->{i};
+	if (wantarray) {
+		$self->{i} = $#{$self->{'data'}} + 1;
+		return splice(@{$self->{'data'}}, $i);
+	}
+	$self->{i} = $i + 1;
+	return $self->{'data'}->[ $i ];
+}
+
+sub CLOSE {
+	my $self = shift;
+	delete $self->{data};
+	delete $self->{i};
+}
+
+sub EOF {
+	my $self = shift;
+	return ($self->{i} >= scalar @{$self->{data}});
+}
+
+
+1; # Famous last words
diff --git a/third_party/git/perl/Git/I18N.pm b/third_party/git/perl/Git/I18N.pm
new file mode 100644
index 000000000000..bfb4fb67a13f
--- /dev/null
+++ b/third_party/git/perl/Git/I18N.pm
@@ -0,0 +1,115 @@
+package Git::I18N;
+use 5.008;
+use strict;
+use warnings;
+BEGIN {
+	require Exporter;
+	if ($] < 5.008003) {
+		*import = \&Exporter::import;
+	} else {
+		# Exporter 5.57 which supports this invocation was
+		# released with perl 5.8.3
+		Exporter->import('import');
+	}
+}
+
+our @EXPORT = qw(__ __n N__);
+our @EXPORT_OK = @EXPORT;
+
+sub __bootstrap_locale_messages {
+	our $TEXTDOMAIN = 'git';
+	our $TEXTDOMAINDIR ||= $ENV{GIT_TEXTDOMAINDIR} || '@@LOCALEDIR@@';
+
+	require POSIX;
+	POSIX->import(qw(setlocale));
+	# Non-core prerequisite module
+	require Locale::Messages;
+	Locale::Messages->import(qw(:locale_h :libintl_h));
+
+	setlocale(LC_MESSAGES(), '');
+	setlocale(LC_CTYPE(), '');
+	textdomain($TEXTDOMAIN);
+	bindtextdomain($TEXTDOMAIN => $TEXTDOMAINDIR);
+
+	return;
+}
+
+BEGIN
+{
+	# Used by our test script to see if it should test fallbacks or
+	# not.
+	our $__HAS_LIBRARY = 1;
+
+	local $@;
+	eval {
+		__bootstrap_locale_messages();
+		*__ = \&Locale::Messages::gettext;
+		*__n = \&Locale::Messages::ngettext;
+		1;
+	} or do {
+		# Tell test.pl that we couldn't load the gettext library.
+		$Git::I18N::__HAS_LIBRARY = 0;
+
+		# Just a fall-through no-op
+		*__ = sub ($) { $_[0] };
+		*__n = sub ($$$) { $_[2] == 1 ? $_[0] : $_[1] };
+	};
+
+	sub N__($) { return shift; }
+}
+
+1;
+
+__END__
+
+=head1 NAME
+
+Git::I18N - Perl interface to Git's Gettext localizations
+
+=head1 SYNOPSIS
+
+	use Git::I18N;
+
+	print __("Welcome to Git!\n");
+
+	printf __("The following error occurred: %s\n"), $error;
+
+	printf __n("committed %d file\n", "committed %d files\n", $files), $files;
+
+
+=head1 DESCRIPTION
+
+Git's internal Perl interface to gettext via L<Locale::Messages>. If
+L<Locale::Messages> can't be loaded (it's not a core module) we
+provide stub passthrough fallbacks.
+
+This is a distilled interface to gettext, see C<info '(gettext)Perl'>
+for the full interface. This module implements only a small part of
+it.
+
+=head1 FUNCTIONS
+
+=head2 __($)
+
+L<Locale::Messages>'s gettext function if all goes well, otherwise our
+passthrough fallback function.
+
+=head2 __n($$$)
+
+L<Locale::Messages>'s ngettext function or passthrough fallback function.
+
+=head2 N__($)
+
+No-operation that only returns its argument. Use this if you want xgettext to
+extract the text to the pot template but do not want to trigger retrival of the
+translation at run time.
+
+=head1 AUTHOR
+
+E<AElig>var ArnfjE<ouml>rE<eth> Bjarmason <avarab@gmail.com>
+
+=head1 COPYRIGHT
+
+Copyright 2010 E<AElig>var ArnfjE<ouml>rE<eth> Bjarmason <avarab@gmail.com>
+
+=cut
diff --git a/third_party/git/perl/Git/IndexInfo.pm b/third_party/git/perl/Git/IndexInfo.pm
new file mode 100644
index 000000000000..a43108c98544
--- /dev/null
+++ b/third_party/git/perl/Git/IndexInfo.pm
@@ -0,0 +1,33 @@
+package Git::IndexInfo;
+use strict;
+use warnings;
+use Git qw/command_input_pipe command_close_pipe/;
+
+sub new {
+	my ($class) = @_;
+	my ($gui, $ctx) = command_input_pipe(qw/update-index -z --index-info/);
+	bless { gui => $gui, ctx => $ctx, nr => 0}, $class;
+}
+
+sub remove {
+	my ($self, $path) = @_;
+	if (print { $self->{gui} } '0 ', 0 x 40, "\t", $path, "\0") {
+		return ++$self->{nr};
+	}
+	undef;
+}
+
+sub update {
+	my ($self, $mode, $hash, $path) = @_;
+	if (print { $self->{gui} } $mode, ' ', $hash, "\t", $path, "\0") {
+		return ++$self->{nr};
+	}
+	undef;
+}
+
+sub DESTROY {
+	my ($self) = @_;
+	command_close_pipe($self->{gui}, $self->{ctx});
+}
+
+1;
diff --git a/third_party/git/perl/Git/LoadCPAN.pm b/third_party/git/perl/Git/LoadCPAN.pm
new file mode 100644
index 000000000000..e5585e75e809
--- /dev/null
+++ b/third_party/git/perl/Git/LoadCPAN.pm
@@ -0,0 +1,104 @@
+package Git::LoadCPAN;
+use 5.008;
+use strict;
+use warnings;
+
+=head1 NAME
+
+Git::LoadCPAN - Wrapper for loading modules from the CPAN (OS) or Git's own copy
+
+=head1 DESCRIPTION
+
+The Perl code in Git depends on some modules from the CPAN, but we
+don't want to make those a hard requirement for anyone building from
+source.
+
+Therefore the L<Git::LoadCPAN> namespace shipped with Git contains
+wrapper modules like C<Git::LoadCPAN::Module::Name> that will first
+attempt to load C<Module::Name> from the OS, and if that doesn't work
+will fall back on C<FromCPAN::Module::Name> shipped with Git itself.
+
+Usually distributors will not ship with Git's Git::FromCPAN tree at
+all via the C<NO_PERL_CPAN_FALLBACKS> option, preferring to use their
+own packaging of CPAN modules instead.
+
+This module is only intended to be used for code shipping in the
+C<git.git> repository. Use it for anything else at your peril!
+
+=cut
+
+# NO_PERL_CPAN_FALLBACKS_STR evades the sed search-replace from the
+# Makefile, and allows for detecting whether the module is loaded from
+# perl/Git as opposed to perl/build/Git, which is useful for one-off
+# testing without having Error.pm et al installed.
+use constant NO_PERL_CPAN_FALLBACKS_STR => '@@' . 'NO_PERL_CPAN_FALLBACKS' . '@@';
+use constant NO_PERL_CPAN_FALLBACKS => (
+	q[@@NO_PERL_CPAN_FALLBACKS@@] ne ''
+	and
+	q[@@NO_PERL_CPAN_FALLBACKS@@] ne NO_PERL_CPAN_FALLBACKS_STR
+);
+
+sub import {
+	shift;
+	my $caller = caller;
+	my %args = @_;
+	my $module = exists $args{module} ? delete $args{module} : die "BUG: Expected 'module' parameter!";
+	my $import = exists $args{import} ? delete $args{import} : die "BUG: Expected 'import' parameter!";
+	die "BUG: Too many arguments!" if keys %args;
+
+	# Foo::Bar to Foo/Bar.pm
+	my $package_pm = $module;
+	$package_pm =~ s[::][/]g;
+	$package_pm .= '.pm';
+
+	eval {
+		require $package_pm;
+		1;
+	} or do {
+		my $error = $@ || "Zombie Error";
+
+		if (NO_PERL_CPAN_FALLBACKS) {
+			chomp(my $error = sprintf <<'THEY_PROMISED', $module);
+BUG: The '%s' module is not here, but NO_PERL_CPAN_FALLBACKS was set!
+
+Git needs this Perl module from the CPAN, and will by default ship
+with a copy of it. This Git was built with NO_PERL_CPAN_FALLBACKS,
+meaning that whoever built it promised to provide this module.
+
+You're seeing this error because they broke that promise, and we can't
+load our fallback version, since we were asked not to install it.
+
+If you're seeing this error and didn't package Git yourself the
+package you're using is broken, or your system is broken. This error
+won't appear if Git is built without NO_PERL_CPAN_FALLBACKS (instead
+we'll use our fallback version of the module).
+THEY_PROMISED
+			die $error;
+		}
+
+		my $Git_LoadCPAN_pm_path = $INC{"Git/LoadCPAN.pm"} || die "BUG: Should have our own path from %INC!";
+
+		require File::Basename;
+		my $Git_LoadCPAN_pm_root = File::Basename::dirname($Git_LoadCPAN_pm_path) || die "BUG: Can't figure out lib/Git dirname from '$Git_LoadCPAN_pm_path'!";
+
+		require File::Spec;
+		my $Git_pm_FromCPAN_root = File::Spec->catdir($Git_LoadCPAN_pm_root, '..', 'FromCPAN');
+		die "BUG: '$Git_pm_FromCPAN_root' should be a directory!" unless -d $Git_pm_FromCPAN_root;
+
+		local @INC = ($Git_pm_FromCPAN_root, @INC);
+		require $package_pm;
+	};
+
+	if ($import) {
+		no strict 'refs';
+		*{"${caller}::import"} = sub {
+			shift;
+			use strict 'refs';
+			unshift @_, $module;
+			goto &{"${module}::import"};
+		};
+		use strict 'refs';
+	}
+}
+
+1;
diff --git a/third_party/git/perl/Git/LoadCPAN/Error.pm b/third_party/git/perl/Git/LoadCPAN/Error.pm
new file mode 100644
index 000000000000..c6d2c45d808b
--- /dev/null
+++ b/third_party/git/perl/Git/LoadCPAN/Error.pm
@@ -0,0 +1,10 @@
+package Git::LoadCPAN::Error;
+use 5.008;
+use strict;
+use warnings;
+use Git::LoadCPAN (
+	module => 'Error',
+	import => 1,
+);
+
+1;
diff --git a/third_party/git/perl/Git/LoadCPAN/Mail/Address.pm b/third_party/git/perl/Git/LoadCPAN/Mail/Address.pm
new file mode 100644
index 000000000000..f70a4f064c3c
--- /dev/null
+++ b/third_party/git/perl/Git/LoadCPAN/Mail/Address.pm
@@ -0,0 +1,10 @@
+package Git::LoadCPAN::Mail::Address;
+use 5.008;
+use strict;
+use warnings;
+use Git::LoadCPAN (
+	module => 'Mail::Address',
+	import => 0,
+);
+
+1;
diff --git a/third_party/git/perl/Git/Packet.pm b/third_party/git/perl/Git/Packet.pm
new file mode 100644
index 000000000000..b75738bed4b5
--- /dev/null
+++ b/third_party/git/perl/Git/Packet.pm
@@ -0,0 +1,173 @@
+package Git::Packet;
+use 5.008;
+use strict;
+use warnings;
+BEGIN {
+	require Exporter;
+	if ($] < 5.008003) {
+		*import = \&Exporter::import;
+	} else {
+		# Exporter 5.57 which supports this invocation was
+		# released with perl 5.8.3
+		Exporter->import('import');
+	}
+}
+
+our @EXPORT = qw(
+			packet_compare_lists
+			packet_bin_read
+			packet_txt_read
+			packet_key_val_read
+			packet_bin_write
+			packet_txt_write
+			packet_flush
+			packet_initialize
+			packet_read_capabilities
+			packet_read_and_check_capabilities
+			packet_check_and_write_capabilities
+		);
+our @EXPORT_OK = @EXPORT;
+
+sub packet_compare_lists {
+	my ($expect, @result) = @_;
+	my $ix;
+	if (scalar @$expect != scalar @result) {
+		return undef;
+	}
+	for ($ix = 0; $ix < $#result; $ix++) {
+		if ($expect->[$ix] ne $result[$ix]) {
+			return undef;
+		}
+	}
+	return 1;
+}
+
+sub packet_bin_read {
+	my $buffer;
+	my $bytes_read = read STDIN, $buffer, 4;
+	if ( $bytes_read == 0 ) {
+		# EOF - Git stopped talking to us!
+		return ( -1, "" );
+	} elsif ( $bytes_read != 4 ) {
+		die "invalid packet: '$buffer'";
+	}
+	my $pkt_size = hex($buffer);
+	if ( $pkt_size == 0 ) {
+		return ( 1, "" );
+	} elsif ( $pkt_size > 4 ) {
+		my $content_size = $pkt_size - 4;
+		$bytes_read = read STDIN, $buffer, $content_size;
+		if ( $bytes_read != $content_size ) {
+			die "invalid packet ($content_size bytes expected; $bytes_read bytes read)";
+		}
+		return ( 0, $buffer );
+	} else {
+		die "invalid packet size: $pkt_size";
+	}
+}
+
+sub remove_final_lf_or_die {
+	my $buf = shift;
+	if ( $buf =~ s/\n$// ) {
+		return $buf;
+	}
+	die "A non-binary line MUST be terminated by an LF.\n"
+	    . "Received: '$buf'";
+}
+
+sub packet_txt_read {
+	my ( $res, $buf ) = packet_bin_read();
+	if ( $res != -1 and $buf ne '' ) {
+		$buf = remove_final_lf_or_die($buf);
+	}
+	return ( $res, $buf );
+}
+
+# Read a text packet, expecting that it is in the form "key=value" for
+# the given $key.  An EOF does not trigger any error and is reported
+# back to the caller (like packet_txt_read() does).  Die if the "key"
+# part of "key=value" does not match the given $key, or the value part
+# is empty.
+sub packet_key_val_read {
+	my ( $key ) = @_;
+	my ( $res, $buf ) = packet_txt_read();
+	if ( $res == -1 or ( $buf =~ s/^$key=// and $buf ne '' ) ) {
+		return ( $res, $buf );
+	}
+	die "bad $key: '$buf'";
+}
+
+sub packet_bin_write {
+	my $buf = shift;
+	print STDOUT sprintf( "%04x", length($buf) + 4 );
+	print STDOUT $buf;
+	STDOUT->flush();
+}
+
+sub packet_txt_write {
+	packet_bin_write( $_[0] . "\n" );
+}
+
+sub packet_flush {
+	print STDOUT sprintf( "%04x", 0 );
+	STDOUT->flush();
+}
+
+sub packet_initialize {
+	my ($name, $version) = @_;
+
+	packet_compare_lists([0, $name . "-client"], packet_txt_read()) ||
+		die "bad initialize";
+	packet_compare_lists([0, "version=" . $version], packet_txt_read()) ||
+		die "bad version";
+	packet_compare_lists([1, ""], packet_bin_read()) ||
+		die "bad version end";
+
+	packet_txt_write( $name . "-server" );
+	packet_txt_write( "version=" . $version );
+	packet_flush();
+}
+
+sub packet_read_capabilities {
+	my @cap;
+	while (1) {
+		my ( $res, $buf ) = packet_bin_read();
+		if ( $res == -1 ) {
+			die "unexpected EOF when reading capabilities";
+		}
+		return ( $res, @cap ) if ( $res != 0 );
+		$buf = remove_final_lf_or_die($buf);
+		unless ( $buf =~ s/capability=// ) {
+			die "bad capability buf: '$buf'";
+		}
+		push @cap, $buf;
+	}
+}
+
+# Read remote capabilities and check them against capabilities we require
+sub packet_read_and_check_capabilities {
+	my @required_caps = @_;
+	my ($res, @remote_caps) = packet_read_capabilities();
+	my %remote_caps = map { $_ => 1 } @remote_caps;
+	foreach (@required_caps) {
+		unless (exists($remote_caps{$_})) {
+			die "required '$_' capability not available from remote" ;
+		}
+	}
+	return %remote_caps;
+}
+
+# Check our capabilities we want to advertise against the remote ones
+# and then advertise our capabilities
+sub packet_check_and_write_capabilities {
+	my ($remote_caps, @our_caps) = @_;
+	foreach (@our_caps) {
+		unless (exists($remote_caps->{$_})) {
+			die "our capability '$_' is not available from remote"
+		}
+		packet_txt_write( "capability=" . $_ );
+	}
+	packet_flush();
+}
+
+1;
diff --git a/third_party/git/perl/Git/SVN.pm b/third_party/git/perl/Git/SVN.pm
new file mode 100644
index 000000000000..76b29659057d
--- /dev/null
+++ b/third_party/git/perl/Git/SVN.pm
@@ -0,0 +1,2553 @@
+package Git::SVN;
+use strict;
+use warnings;
+use Fcntl qw/:DEFAULT :seek/;
+use constant rev_map_fmt => 'NH40';
+use vars qw/$_no_metadata
+            $_repack $_repack_flags $_use_svm_props $_head
+            $_use_svnsync_props $no_reuse_existing
+	    $_use_log_author $_add_author_from $_localtime/;
+use Carp qw/croak/;
+use File::Path qw/mkpath/;
+use IPC::Open3;
+use Memoize;  # core since 5.8.0, Jul 2002
+use POSIX qw(:signal_h);
+use Time::Local;
+
+use Git qw(
+    command
+    command_oneline
+    command_noisy
+    command_output_pipe
+    command_close_pipe
+    get_tz_offset
+);
+use Git::SVN::Utils qw(
+	fatal
+	can_compress
+	join_paths
+	canonicalize_path
+	canonicalize_url
+	add_path_to_url
+);
+
+my $memo_backend;
+our $_follow_parent  = 1;
+our $_minimize_url   = 'unset';
+our $default_repo_id = 'svn';
+our $default_ref_id  = $ENV{GIT_SVN_ID} || 'git-svn';
+
+my ($_gc_nr, $_gc_period);
+
+# properties that we do not log:
+my %SKIP_PROP;
+BEGIN {
+	%SKIP_PROP = map { $_ => 1 } qw/svn:wc:ra_dav:version-url
+	                                svn:special svn:executable
+	                                svn:entry:committed-rev
+	                                svn:entry:last-author
+	                                svn:entry:uuid
+	                                svn:entry:committed-date/;
+
+	# some options are read globally, but can be overridden locally
+	# per [svn-remote "..."] section.  Command-line options will *NOT*
+	# override options set in an [svn-remote "..."] section
+	no strict 'refs';
+	for my $option (qw/follow_parent no_metadata use_svm_props
+			   use_svnsync_props/) {
+		my $key = $option;
+		$key =~ tr/_//d;
+		my $prop = "-$option";
+		*$option = sub {
+			my ($self) = @_;
+			return $self->{$prop} if exists $self->{$prop};
+			my $k = "svn-remote.$self->{repo_id}.$key";
+			eval { command_oneline(qw/config --get/, $k) };
+			if ($@) {
+				$self->{$prop} = ${"Git::SVN::_$option"};
+			} else {
+				my $v = command_oneline(qw/config --bool/,$k);
+				$self->{$prop} = $v eq 'false' ? 0 : 1;
+			}
+			return $self->{$prop};
+		}
+	}
+}
+
+
+my (%LOCKFILES, %INDEX_FILES);
+END {
+	unlink keys %LOCKFILES if %LOCKFILES;
+	unlink keys %INDEX_FILES if %INDEX_FILES;
+}
+
+sub resolve_local_globs {
+	my ($url, $fetch, $glob_spec) = @_;
+	return unless defined $glob_spec;
+	my $ref = $glob_spec->{ref};
+	my $path = $glob_spec->{path};
+	foreach (command(qw#for-each-ref --format=%(refname) refs/#)) {
+		next unless m#^$ref->{regex}$#;
+		my $p = $1;
+		my $pathname = desanitize_refname($path->full_path($p));
+		my $refname = desanitize_refname($ref->full_path($p));
+		if (my $existing = $fetch->{$pathname}) {
+			if ($existing ne $refname) {
+				die "Refspec conflict:\n",
+				    "existing: $existing\n",
+				    " globbed: $refname\n";
+			}
+			my $u = (::cmt_metadata("$refname"))[0];
+			if (!defined($u)) {
+				warn
+"W: $refname: no associated commit metadata from SVN, skipping\n";
+				next;
+			}
+			$u =~ s!^\Q$url\E(/|$)!! or die
+			  "$refname: '$url' not found in '$u'\n";
+			if ($pathname ne $u) {
+				warn "W: Refspec glob conflict ",
+				     "(ref: $refname):\n",
+				     "expected path: $pathname\n",
+				     "    real path: $u\n",
+				     "Continuing ahead with $u\n";
+				next;
+			}
+		} else {
+			$fetch->{$pathname} = $refname;
+		}
+	}
+}
+
+sub parse_revision_argument {
+	my ($base, $head) = @_;
+	if (!defined $::_revision || $::_revision eq 'BASE:HEAD') {
+		return ($base, $head);
+	}
+	return ($1, $2) if ($::_revision =~ /^(\d+):(\d+)$/);
+	return ($::_revision, $::_revision) if ($::_revision =~ /^\d+$/);
+	return ($head, $head) if ($::_revision eq 'HEAD');
+	return ($base, $1) if ($::_revision =~ /^BASE:(\d+)$/);
+	return ($1, $head) if ($::_revision =~ /^(\d+):HEAD$/);
+	die "revision argument: $::_revision not understood by git-svn\n";
+}
+
+sub fetch_all {
+	my ($repo_id, $remotes) = @_;
+	if (ref $repo_id) {
+		my $gs = $repo_id;
+		$repo_id = undef;
+		$repo_id = $gs->{repo_id};
+	}
+	$remotes ||= read_all_remotes();
+	my $remote = $remotes->{$repo_id} or
+	             die "[svn-remote \"$repo_id\"] unknown\n";
+	my $fetch = $remote->{fetch};
+	my $url = $remote->{url} or die "svn-remote.$repo_id.url not defined\n";
+	my (@gs, @globs);
+	my $ra = Git::SVN::Ra->new($url);
+	my $uuid = $ra->get_uuid;
+	my $head = $ra->get_latest_revnum;
+
+	# ignore errors, $head revision may not even exist anymore
+	eval { $ra->get_log("", $head, 0, 1, 0, 1, sub { $head = $_[1] }) };
+	warn "W: $@\n" if $@;
+
+	my $base = defined $fetch ? $head : 0;
+
+	# read the max revs for wildcard expansion (branches/*, tags/*)
+	foreach my $t (qw/branches tags/) {
+		defined $remote->{$t} or next;
+		push @globs, @{$remote->{$t}};
+
+		my $max_rev = eval { tmp_config(qw/--int --get/,
+		                         "svn-remote.$repo_id.${t}-maxRev") };
+		if (defined $max_rev && ($max_rev < $base)) {
+			$base = $max_rev;
+		} elsif (!defined $max_rev) {
+			$base = 0;
+		}
+	}
+
+	if ($fetch) {
+		foreach my $p (sort keys %$fetch) {
+			my $gs = Git::SVN->new($fetch->{$p}, $repo_id, $p);
+			my $lr = $gs->rev_map_max;
+			if (defined $lr) {
+				$base = $lr if ($lr < $base);
+			}
+			push @gs, $gs;
+		}
+	}
+
+	($base, $head) = parse_revision_argument($base, $head);
+	$ra->gs_fetch_loop_common($base, $head, \@gs, \@globs);
+}
+
+sub read_all_remotes {
+	my $r = {};
+	my $use_svm_props = eval { command_oneline(qw/config --bool
+	    svn.useSvmProps/) };
+	$use_svm_props = $use_svm_props eq 'true' if $use_svm_props;
+	my $svn_refspec = qr{\s*(.*?)\s*:\s*(.+?)\s*};
+	foreach (grep { s/^svn-remote\.// } command(qw/config -l/)) {
+		if (m!^(.+)\.fetch=$svn_refspec$!) {
+			my ($remote, $local_ref, $remote_ref) = ($1, $2, $3);
+			die("svn-remote.$remote: remote ref '$remote_ref' "
+			    . "must start with 'refs/'\n")
+				unless $remote_ref =~ m{^refs/};
+			$local_ref = uri_decode($local_ref);
+			$r->{$remote}->{fetch}->{$local_ref} = $remote_ref;
+			$r->{$remote}->{svm} = {} if $use_svm_props;
+		} elsif (m!^(.+)\.usesvmprops=\s*(.*)\s*$!) {
+			$r->{$1}->{svm} = {};
+		} elsif (m!^(.+)\.url=\s*(.*)\s*$!) {
+			$r->{$1}->{url} = canonicalize_url($2);
+		} elsif (m!^(.+)\.pushurl=\s*(.*)\s*$!) {
+			$r->{$1}->{pushurl} = canonicalize_url($2);
+		} elsif (m!^(.+)\.ignore-refs=\s*(.*)\s*$!) {
+			$r->{$1}->{ignore_refs_regex} = $2;
+		} elsif (m!^(.+)\.(branches|tags)=$svn_refspec$!) {
+			my ($remote, $t, $local_ref, $remote_ref) =
+			                                     ($1, $2, $3, $4);
+			die("svn-remote.$remote: remote ref '$remote_ref' ($t) "
+			    . "must start with 'refs/'\n")
+				unless $remote_ref =~ m{^refs/};
+			$local_ref = uri_decode($local_ref);
+
+			require Git::SVN::GlobSpec;
+			my $rs = {
+			    t => $t,
+			    remote => $remote,
+			    path => Git::SVN::GlobSpec->new($local_ref, 1),
+			    ref => Git::SVN::GlobSpec->new($remote_ref, 0) };
+			if (length($rs->{ref}->{right}) != 0) {
+				die "The '*' glob character must be the last ",
+				    "character of '$remote_ref'\n";
+			}
+			push @{ $r->{$remote}->{$t} }, $rs;
+		}
+	}
+
+	map {
+		if (defined $r->{$_}->{svm}) {
+			my $svm;
+			eval {
+				my $section = "svn-remote.$_";
+				$svm = {
+					source => tmp_config('--get',
+					    "$section.svm-source"),
+					replace => tmp_config('--get',
+					    "$section.svm-replace"),
+				}
+			};
+			$r->{$_}->{svm} = $svm;
+		}
+	} keys %$r;
+
+	foreach my $remote (keys %$r) {
+		foreach ( grep { defined $_ }
+			  map { $r->{$remote}->{$_} } qw(branches tags) ) {
+			foreach my $rs ( @$_ ) {
+				$rs->{ignore_refs_regex} =
+				    $r->{$remote}->{ignore_refs_regex};
+			}
+		}
+	}
+
+	$r;
+}
+
+sub init_vars {
+	$_gc_nr = $_gc_period = 1000;
+	if (defined $_repack || defined $_repack_flags) {
+	       warn "Repack options are obsolete; they have no effect.\n";
+	}
+}
+
+sub verify_remotes_sanity {
+	return unless -d $ENV{GIT_DIR};
+	my %seen;
+	foreach (command(qw/config -l/)) {
+		if (m!^svn-remote\.(?:.+)\.fetch=.*:refs/remotes/(\S+)\s*$!) {
+			if ($seen{$1}) {
+				die "Remote ref refs/remote/$1 is tracked by",
+				    "\n  \"$_\"\nand\n  \"$seen{$1}\"\n",
+				    "Please resolve this ambiguity in ",
+				    "your git configuration file before ",
+				    "continuing\n";
+			}
+			$seen{$1} = $_;
+		}
+	}
+}
+
+sub find_existing_remote {
+	my ($url, $remotes) = @_;
+	return undef if $no_reuse_existing;
+	my $existing;
+	foreach my $repo_id (keys %$remotes) {
+		my $u = $remotes->{$repo_id}->{url} or next;
+		next if $u ne $url;
+		$existing = $repo_id;
+		last;
+	}
+	$existing;
+}
+
+sub init_remote_config {
+	my ($self, $url, $no_write) = @_;
+	$url = canonicalize_url($url);
+	my $r = read_all_remotes();
+	my $existing = find_existing_remote($url, $r);
+	if ($existing) {
+		unless ($no_write) {
+			print STDERR "Using existing ",
+				     "[svn-remote \"$existing\"]\n";
+		}
+		$self->{repo_id} = $existing;
+	} elsif ($_minimize_url) {
+		my $min_url = Git::SVN::Ra->new($url)->minimize_url;
+		$existing = find_existing_remote($min_url, $r);
+		if ($existing) {
+			unless ($no_write) {
+				print STDERR "Using existing ",
+					     "[svn-remote \"$existing\"]\n";
+			}
+			$self->{repo_id} = $existing;
+		}
+		if ($min_url ne $url) {
+			unless ($no_write) {
+				print STDERR "Using higher level of URL: ",
+					     "$url => $min_url\n";
+			}
+			my $old_path = $self->path;
+			$url =~ s!^\Q$min_url\E(/|$)!!;
+			$url = join_paths($url, $old_path);
+			$self->path($url);
+			$url = $min_url;
+		}
+	}
+	my $orig_url;
+	if (!$existing) {
+		# verify that we aren't overwriting anything:
+		$orig_url = eval {
+			command_oneline('config', '--get',
+					"svn-remote.$self->{repo_id}.url")
+		};
+		if ($orig_url && ($orig_url ne $url)) {
+			die "svn-remote.$self->{repo_id}.url already set: ",
+			    "$orig_url\nwanted to set to: $url\n";
+		}
+	}
+	my ($xrepo_id, $xpath) = find_ref($self->refname);
+	if (!$no_write && defined $xpath) {
+		die "svn-remote.$xrepo_id.fetch already set to track ",
+		    "$xpath:", $self->refname, "\n";
+	}
+	unless ($no_write) {
+		command_noisy('config',
+			      "svn-remote.$self->{repo_id}.url", $url);
+		my $path = $self->path;
+		$path =~ s{^/}{};
+		$path =~ s{%([0-9A-F]{2})}{chr hex($1)}ieg;
+		$self->path($path);
+		command_noisy('config', '--add',
+			      "svn-remote.$self->{repo_id}.fetch",
+			      $self->path.":".$self->refname);
+	}
+	$self->url($url);
+}
+
+sub find_by_url { # repos_root and, path are optional
+	my ($class, $full_url, $repos_root, $path) = @_;
+
+	$full_url = canonicalize_url($full_url);
+
+	return undef unless defined $full_url;
+	remove_username($full_url);
+	remove_username($repos_root) if defined $repos_root;
+	my $remotes = read_all_remotes();
+	if (defined $full_url && defined $repos_root && !defined $path) {
+		$path = $full_url;
+		$path =~ s#^\Q$repos_root\E(?:/|$)##;
+	}
+	foreach my $repo_id (keys %$remotes) {
+		my $u = $remotes->{$repo_id}->{url} or next;
+		remove_username($u);
+		next if defined $repos_root && $repos_root ne $u;
+
+		my $fetch = $remotes->{$repo_id}->{fetch} || {};
+		foreach my $t (qw/branches tags/) {
+			foreach my $globspec (@{$remotes->{$repo_id}->{$t}}) {
+				resolve_local_globs($u, $fetch, $globspec);
+			}
+		}
+		my $p = $path;
+		my $rwr = rewrite_root({repo_id => $repo_id});
+		my $svm = $remotes->{$repo_id}->{svm}
+			if defined $remotes->{$repo_id}->{svm};
+		unless (defined $p) {
+			$p = $full_url;
+			my $z = $u;
+			my $prefix = '';
+			if ($rwr) {
+				$z = $rwr;
+				remove_username($z);
+			} elsif (defined $svm) {
+				$z = $svm->{source};
+				$prefix = $svm->{replace};
+				$prefix =~ s#^\Q$u\E(?:/|$)##;
+				$prefix =~ s#/$##;
+			}
+			$p =~ s#^\Q$z\E(?:/|$)#$prefix# or next;
+		}
+
+		# remote fetch paths are not URI escaped.  Decode ours
+		# so they match
+		$p = uri_decode($p);
+
+		foreach my $f (keys %$fetch) {
+			next if $f ne $p;
+			return Git::SVN->new($fetch->{$f}, $repo_id, $f);
+		}
+	}
+	undef;
+}
+
+sub init {
+	my ($class, $url, $path, $repo_id, $ref_id, $no_write) = @_;
+	my $self = _new($class, $repo_id, $ref_id, $path);
+	if (defined $url) {
+		$self->init_remote_config($url, $no_write);
+	}
+	$self;
+}
+
+sub find_ref {
+	my ($ref_id) = @_;
+	foreach (command(qw/config -l/)) {
+		next unless m!^svn-remote\.(.+)\.fetch=
+		              \s*(.*?)\s*:\s*(.+?)\s*$!x;
+		my ($repo_id, $path, $ref) = ($1, $2, $3);
+		if ($ref eq $ref_id) {
+			$path = '' if ($path =~ m#^\./?#);
+			return ($repo_id, $path);
+		}
+	}
+	(undef, undef, undef);
+}
+
+sub new {
+	my ($class, $ref_id, $repo_id, $path) = @_;
+	if (defined $ref_id && !defined $repo_id && !defined $path) {
+		($repo_id, $path) = find_ref($ref_id);
+		if (!defined $repo_id) {
+			die "Could not find a \"svn-remote.*.fetch\" key ",
+			    "in the repository configuration matching: ",
+			    "$ref_id\n";
+		}
+	}
+	my $self = _new($class, $repo_id, $ref_id, $path);
+	if (!defined $self->path || !length $self->path) {
+		my $fetch = command_oneline('config', '--get',
+		                            "svn-remote.$repo_id.fetch",
+		                            ":$ref_id\$") or
+		     die "Failed to read \"svn-remote.$repo_id.fetch\" ",
+		         "\":$ref_id\$\" in config\n";
+		my($path) = split(/\s*:\s*/, $fetch);
+		$self->path($path);
+	}
+	{
+		my $path = $self->path;
+		$path =~ s{\A/}{};
+		$path =~ s{/\z}{};
+		$self->path($path);
+	}
+	my $url = command_oneline('config', '--get',
+	                          "svn-remote.$repo_id.url") or
+                  die "Failed to read \"svn-remote.$repo_id.url\" in config\n";
+	$self->url($url);
+	$self->{pushurl} = eval { command_oneline('config', '--get',
+	                          "svn-remote.$repo_id.pushurl") };
+	$self->rebuild;
+	$self;
+}
+
+sub refname {
+	my ($refname) = $_[0]->{ref_id} ;
+
+	# It cannot end with a slash /, we'll throw up on this because
+	# SVN can't have directories with a slash in their name, either:
+	if ($refname =~ m{/$}) {
+		die "ref: '$refname' ends with a trailing slash; this is ",
+		    "not permitted by git or Subversion\n";
+	}
+
+	# It cannot have ASCII control character space, tilde ~, caret ^,
+	# colon :, question-mark ?, asterisk *, space, or open bracket [
+	# anywhere.
+	#
+	# Additionally, % must be escaped because it is used for escaping
+	# and we want our escaped refname to be reversible
+	$refname =~ s{([ \%~\^:\?\*\[\t\\])}{sprintf('%%%02X',ord($1))}eg;
+
+	# no slash-separated component can begin with a dot .
+	# /.* becomes /%2E*
+	$refname =~ s{/\.}{/%2E}g;
+
+	# It cannot have two consecutive dots .. anywhere
+	# .. becomes %2E%2E
+	$refname =~ s{\.\.}{%2E%2E}g;
+
+	# trailing dots and .lock are not allowed
+	# .$ becomes %2E and .lock becomes %2Elock
+	$refname =~ s{\.(?=$|lock$)}{%2E};
+
+	# the sequence @{ is used to access the reflog
+	# @{ becomes %40{
+	$refname =~ s{\@\{}{%40\{}g;
+
+	return $refname;
+}
+
+sub desanitize_refname {
+	my ($refname) = @_;
+	$refname =~ s{%(?:([0-9A-F]{2}))}{chr hex($1)}eg;
+	return $refname;
+}
+
+sub svm_uuid {
+	my ($self) = @_;
+	return $self->{svm}->{uuid} if $self->svm;
+	$self->ra;
+	unless ($self->{svm}) {
+		die "SVM UUID not cached, and reading remotely failed\n";
+	}
+	$self->{svm}->{uuid};
+}
+
+sub svm {
+	my ($self) = @_;
+	return $self->{svm} if $self->{svm};
+	my $svm;
+	# see if we have it in our config, first:
+	eval {
+		my $section = "svn-remote.$self->{repo_id}";
+		$svm = {
+		  source => tmp_config('--get', "$section.svm-source"),
+		  uuid => tmp_config('--get', "$section.svm-uuid"),
+		  replace => tmp_config('--get', "$section.svm-replace"),
+		}
+	};
+	if ($svm && $svm->{source} && $svm->{uuid} && $svm->{replace}) {
+		$self->{svm} = $svm;
+	}
+	$self->{svm};
+}
+
+sub _set_svm_vars {
+	my ($self, $ra) = @_;
+	return $ra if $self->svm;
+
+	my @err = ( "useSvmProps set, but failed to read SVM properties\n",
+		    "(svm:source, svm:uuid) ",
+		    "from the following URLs:\n" );
+	sub read_svm_props {
+		my ($self, $ra, $path, $r) = @_;
+		my $props = ($ra->get_dir($path, $r))[2];
+		my $src = $props->{'svm:source'};
+		my $uuid = $props->{'svm:uuid'};
+		return undef if (!$src || !$uuid);
+
+		chomp($src, $uuid);
+
+		$uuid =~ m{^[0-9a-f\-]{30,}$}i
+		    or die "doesn't look right - svm:uuid is '$uuid'\n";
+
+		# the '!' is used to mark the repos_root!/relative/path
+		$src =~ s{/?!/?}{/};
+		$src =~ s{/+$}{}; # no trailing slashes please
+		# username is of no interest
+		$src =~ s{(^[a-z\+]*://)[^/@]*@}{$1};
+
+		my $replace = add_path_to_url($ra->url, $path);
+
+		my $section = "svn-remote.$self->{repo_id}";
+		tmp_config("$section.svm-source", $src);
+		tmp_config("$section.svm-replace", $replace);
+		tmp_config("$section.svm-uuid", $uuid);
+		$self->{svm} = {
+			source => $src,
+			uuid => $uuid,
+			replace => $replace
+		};
+	}
+
+	my $r = $ra->get_latest_revnum;
+	my $path = $self->path;
+	my %tried;
+	while (length $path) {
+		my $try = add_path_to_url($self->url, $path);
+		unless ($tried{$try}) {
+			return $ra if $self->read_svm_props($ra, $path, $r);
+			$tried{$try} = 1;
+		}
+		$path =~ s#/?[^/]+$##;
+	}
+	die "Path: '$path' should be ''\n" if $path ne '';
+	return $ra if $self->read_svm_props($ra, $path, $r);
+	$tried{ add_path_to_url($self->url, $path) } = 1;
+
+	if ($ra->{repos_root} eq $self->url) {
+		die @err, (map { "  $_\n" } keys %tried), "\n";
+	}
+
+	# nope, make sure we're connected to the repository root:
+	my $ok;
+	my @tried_b;
+	$path = $ra->{svn_path};
+	$ra = Git::SVN::Ra->new($ra->{repos_root});
+	while (length $path) {
+		my $try = add_path_to_url($ra->url, $path);
+		unless ($tried{$try}) {
+			$ok = $self->read_svm_props($ra, $path, $r);
+			last if $ok;
+			$tried{$try} = 1;
+		}
+		$path =~ s#/?[^/]+$##;
+	}
+	die "Path: '$path' should be ''\n" if $path ne '';
+	$ok ||= $self->read_svm_props($ra, $path, $r);
+	$tried{ add_path_to_url($ra->url, $path) } = 1;
+	if (!$ok) {
+		die @err, (map { "  $_\n" } keys %tried), "\n";
+	}
+	Git::SVN::Ra->new($self->url);
+}
+
+sub svnsync {
+	my ($self) = @_;
+	return $self->{svnsync} if $self->{svnsync};
+
+	if ($self->no_metadata) {
+		die "Can't have both 'noMetadata' and ",
+		    "'useSvnsyncProps' options set!\n";
+	}
+	if ($self->rewrite_root) {
+		die "Can't have both 'useSvnsyncProps' and 'rewriteRoot' ",
+		    "options set!\n";
+	}
+	if ($self->rewrite_uuid) {
+		die "Can't have both 'useSvnsyncProps' and 'rewriteUUID' ",
+		    "options set!\n";
+	}
+
+	my $svnsync;
+	# see if we have it in our config, first:
+	eval {
+		my $section = "svn-remote.$self->{repo_id}";
+
+		my $url = tmp_config('--get', "$section.svnsync-url");
+		($url) = ($url =~ m{^([a-z\+]+://\S+)$}) or
+		   die "doesn't look right - svn:sync-from-url is '$url'\n";
+
+		my $uuid = tmp_config('--get', "$section.svnsync-uuid");
+		($uuid) = ($uuid =~ m{^([0-9a-f\-]{30,})$}i) or
+		   die "doesn't look right - svn:sync-from-uuid is '$uuid'\n";
+
+		$svnsync = { url => $url, uuid => $uuid }
+	};
+	if ($svnsync && $svnsync->{url} && $svnsync->{uuid}) {
+		return $self->{svnsync} = $svnsync;
+	}
+
+	my $err = "useSvnsyncProps set, but failed to read " .
+	          "svnsync property: svn:sync-from-";
+	my $rp = $self->ra->rev_proplist(0);
+
+	my $url = $rp->{'svn:sync-from-url'} or die $err . "url\n";
+	($url) = ($url =~ m{^([a-z\+]+://\S+)$}) or
+	           die "doesn't look right - svn:sync-from-url is '$url'\n";
+
+	my $uuid = $rp->{'svn:sync-from-uuid'} or die $err . "uuid\n";
+	($uuid) = ($uuid =~ m{^([0-9a-f\-]{30,})$}i) or
+	           die "doesn't look right - svn:sync-from-uuid is '$uuid'\n";
+
+	my $section = "svn-remote.$self->{repo_id}";
+	tmp_config('--add', "$section.svnsync-uuid", $uuid);
+	tmp_config('--add', "$section.svnsync-url", $url);
+	return $self->{svnsync} = { url => $url, uuid => $uuid };
+}
+
+# this allows us to memoize our SVN::Ra UUID locally and avoid a
+# remote lookup (useful for 'git svn log').
+sub ra_uuid {
+	my ($self) = @_;
+	unless ($self->{ra_uuid}) {
+		my $key = "svn-remote.$self->{repo_id}.uuid";
+		my $uuid = eval { tmp_config('--get', $key) };
+		if (!$@ && $uuid && $uuid =~ /^([a-f\d\-]{30,})$/i) {
+			$self->{ra_uuid} = $uuid;
+		} else {
+			die "ra_uuid called without URL\n" unless $self->url;
+			$self->{ra_uuid} = $self->ra->get_uuid;
+			tmp_config('--add', $key, $self->{ra_uuid});
+		}
+	}
+	$self->{ra_uuid};
+}
+
+sub _set_repos_root {
+	my ($self, $repos_root) = @_;
+	my $k = "svn-remote.$self->{repo_id}.reposRoot";
+	$repos_root ||= $self->ra->{repos_root};
+	tmp_config($k, $repos_root);
+	$repos_root;
+}
+
+sub repos_root {
+	my ($self) = @_;
+	my $k = "svn-remote.$self->{repo_id}.reposRoot";
+	eval { tmp_config('--get', $k) } || $self->_set_repos_root;
+}
+
+sub ra {
+	my ($self) = shift;
+	my $ra = Git::SVN::Ra->new($self->url);
+	$self->_set_repos_root($ra->{repos_root});
+	if ($self->use_svm_props && !$self->{svm}) {
+		if ($self->no_metadata) {
+			die "Can't have both 'noMetadata' and ",
+			    "'useSvmProps' options set!\n";
+		} elsif ($self->use_svnsync_props) {
+			die "Can't have both 'useSvnsyncProps' and ",
+			    "'useSvmProps' options set!\n";
+		}
+		$ra = $self->_set_svm_vars($ra);
+		$self->{-want_revprops} = 1;
+	}
+	$ra;
+}
+
+# prop_walk(PATH, REV, SUB)
+# -------------------------
+# Recursively traverse PATH at revision REV and invoke SUB for each
+# directory that contains a SVN property.  SUB will be invoked as
+# follows:  &SUB(gs, path, props);  where `gs' is this instance of
+# Git::SVN, `path' the path to the directory where the properties
+# `props' were found.  The `path' will be relative to point of checkout,
+# that is, if url://repo/trunk is the current Git branch, and that
+# directory contains a sub-directory `d', SUB will be invoked with `/d/'
+# as `path' (note the trailing `/').
+sub prop_walk {
+	my ($self, $path, $rev, $sub) = @_;
+
+	$path =~ s#^/##;
+	my ($dirent, undef, $props) = $self->ra->get_dir($path, $rev);
+	$path =~ s#^/*#/#g;
+	my $p = $path;
+	# Strip the irrelevant part of the path.
+	$p =~ s#^/+\Q@{[$self->path]}\E(/|$)#/#;
+	# Ensure the path is terminated by a `/'.
+	$p =~ s#/*$#/#;
+
+	# The properties contain all the internal SVN stuff nobody
+	# (usually) cares about.
+	my $interesting_props = 0;
+	foreach (keys %{$props}) {
+		# If it doesn't start with `svn:', it must be a
+		# user-defined property.
+		++$interesting_props and next if $_ !~ /^svn:/;
+		# FIXME: Fragile, if SVN adds new public properties,
+		# this needs to be updated.
+		++$interesting_props if /^svn:(?:ignore|keywords|executable
+		                                 |eol-style|mime-type
+						 |externals|needs-lock)$/x;
+	}
+	&$sub($self, $p, $props) if $interesting_props;
+
+	foreach (sort keys %$dirent) {
+		next if $dirent->{$_}->{kind} != $SVN::Node::dir;
+		$self->prop_walk($self->path . $p . $_, $rev, $sub);
+	}
+}
+
+sub last_rev { ($_[0]->last_rev_commit)[0] }
+sub last_commit { ($_[0]->last_rev_commit)[1] }
+
+# returns the newest SVN revision number and newest commit SHA1
+sub last_rev_commit {
+	my ($self) = @_;
+	if (defined $self->{last_rev} && defined $self->{last_commit}) {
+		return ($self->{last_rev}, $self->{last_commit});
+	}
+	my $c = ::verify_ref($self->refname.'^0');
+	if ($c && !$self->use_svm_props && !$self->no_metadata) {
+		my $rev = (::cmt_metadata($c))[1];
+		if (defined $rev) {
+			($self->{last_rev}, $self->{last_commit}) = ($rev, $c);
+			return ($rev, $c);
+		}
+	}
+	my $map_path = $self->map_path;
+	unless (-e $map_path) {
+		($self->{last_rev}, $self->{last_commit}) = (undef, undef);
+		return (undef, undef);
+	}
+	my ($rev, $commit) = $self->rev_map_max(1);
+	($self->{last_rev}, $self->{last_commit}) = ($rev, $commit);
+	return ($rev, $commit);
+}
+
+sub get_fetch_range {
+	my ($self, $min, $max) = @_;
+	$max ||= $self->ra->get_latest_revnum;
+	$min ||= $self->rev_map_max;
+	(++$min, $max);
+}
+
+sub svn_dir {
+	command_oneline(qw(rev-parse --git-path svn));
+}
+
+sub tmp_config {
+	my (@args) = @_;
+	my $svn_dir = svn_dir();
+	my $old_def_config = "$svn_dir/config";
+	my $config = "$svn_dir/.metadata";
+	if (! -f $config && -f $old_def_config) {
+		rename $old_def_config, $config or
+		       die "Failed rename $old_def_config => $config: $!\n";
+	}
+	my $old_config = $ENV{GIT_CONFIG};
+	$ENV{GIT_CONFIG} = $config;
+	$@ = undef;
+	my @ret = eval {
+		unless (-f $config) {
+			mkfile($config);
+			open my $fh, '>', $config or
+			    die "Can't open $config: $!\n";
+			print $fh "; This file is used internally by ",
+			          "git-svn\n" or die
+				  "Couldn't write to $config: $!\n";
+			print $fh "; You should not have to edit it\n" or
+			      die "Couldn't write to $config: $!\n";
+			close $fh or die "Couldn't close $config: $!\n";
+		}
+		command('config', @args);
+	};
+	my $err = $@;
+	if (defined $old_config) {
+		$ENV{GIT_CONFIG} = $old_config;
+	} else {
+		delete $ENV{GIT_CONFIG};
+	}
+	die $err if $err;
+	wantarray ? @ret : $ret[0];
+}
+
+sub tmp_index_do {
+	my ($self, $sub) = @_;
+	my $old_index = $ENV{GIT_INDEX_FILE};
+	$ENV{GIT_INDEX_FILE} = $self->{index};
+	$@ = undef;
+	my @ret = eval {
+		my ($dir, $base) = ($self->{index} =~ m#^(.*?)/?([^/]+)$#);
+		mkpath([$dir]) unless -d $dir;
+		&$sub;
+	};
+	my $err = $@;
+	if (defined $old_index) {
+		$ENV{GIT_INDEX_FILE} = $old_index;
+	} else {
+		delete $ENV{GIT_INDEX_FILE};
+	}
+	die $err if $err;
+	wantarray ? @ret : $ret[0];
+}
+
+sub assert_index_clean {
+	my ($self, $treeish) = @_;
+
+	$self->tmp_index_do(sub {
+		command_noisy('read-tree', $treeish) unless -e $self->{index};
+		my $x = command_oneline('write-tree');
+		my ($y) = (command(qw/cat-file commit/, $treeish) =~
+		           /^tree ($::sha1)/mo);
+		return if $y eq $x;
+
+		warn "Index mismatch: $y != $x\nrereading $treeish\n";
+		unlink $self->{index} or die "unlink $self->{index}: $!\n";
+		command_noisy('read-tree', $treeish);
+		$x = command_oneline('write-tree');
+		if ($y ne $x) {
+			fatal "trees ($treeish) $y != $x\n",
+			      "Something is seriously wrong...";
+		}
+	});
+}
+
+sub get_commit_parents {
+	my ($self, $log_entry) = @_;
+	my (%seen, @ret, @tmp);
+	# legacy support for 'set-tree'; this is only used by set_tree_cb:
+	if (my $ip = $self->{inject_parents}) {
+		if (my $commit = delete $ip->{$log_entry->{revision}}) {
+			push @tmp, $commit;
+		}
+	}
+	if (my $cur = ::verify_ref($self->refname.'^0')) {
+		push @tmp, $cur;
+	}
+	if (my $ipd = $self->{inject_parents_dcommit}) {
+		if (my $commit = delete $ipd->{$log_entry->{revision}}) {
+			push @tmp, @$commit;
+		}
+	}
+	push @tmp, $_ foreach (@{$log_entry->{parents}}, @tmp);
+	while (my $p = shift @tmp) {
+		next if $seen{$p};
+		$seen{$p} = 1;
+		push @ret, $p;
+	}
+	@ret;
+}
+
+sub rewrite_root {
+	my ($self) = @_;
+	return $self->{-rewrite_root} if exists $self->{-rewrite_root};
+	my $k = "svn-remote.$self->{repo_id}.rewriteRoot";
+	my $rwr = eval { command_oneline(qw/config --get/, $k) };
+	if ($rwr) {
+		$rwr =~ s#/+$##;
+		if ($rwr !~ m#^[a-z\+]+://#) {
+			die "$rwr is not a valid URL (key: $k)\n";
+		}
+	}
+	$self->{-rewrite_root} = $rwr;
+}
+
+sub rewrite_uuid {
+	my ($self) = @_;
+	return $self->{-rewrite_uuid} if exists $self->{-rewrite_uuid};
+	my $k = "svn-remote.$self->{repo_id}.rewriteUUID";
+	my $rwid = eval { command_oneline(qw/config --get/, $k) };
+	if ($rwid) {
+		$rwid =~ s#/+$##;
+		if ($rwid !~ m#^[a-f0-9]{8}-(?:[a-f0-9]{4}-){3}[a-f0-9]{12}$#) {
+			die "$rwid is not a valid UUID (key: $k)\n";
+		}
+	}
+	$self->{-rewrite_uuid} = $rwid;
+}
+
+sub metadata_url {
+	my ($self) = @_;
+	my $url = $self->rewrite_root || $self->url;
+	return canonicalize_url( add_path_to_url( $url, $self->path ) );
+}
+
+sub full_url {
+	my ($self) = @_;
+	return canonicalize_url( add_path_to_url( $self->url, $self->path ) );
+}
+
+sub full_pushurl {
+	my ($self) = @_;
+	if ($self->{pushurl}) {
+		return canonicalize_url( add_path_to_url( $self->{pushurl}, $self->path ) );
+	} else {
+		return $self->full_url;
+	}
+}
+
+sub set_commit_header_env {
+	my ($log_entry) = @_;
+	my %env;
+	foreach my $ned (qw/NAME EMAIL DATE/) {
+		foreach my $ac (qw/AUTHOR COMMITTER/) {
+			$env{"GIT_${ac}_${ned}"} = $ENV{"GIT_${ac}_${ned}"};
+		}
+	}
+
+	$ENV{GIT_AUTHOR_NAME} = $log_entry->{name};
+	$ENV{GIT_AUTHOR_EMAIL} = $log_entry->{email};
+	$ENV{GIT_AUTHOR_DATE} = $ENV{GIT_COMMITTER_DATE} = $log_entry->{date};
+
+	$ENV{GIT_COMMITTER_NAME} = (defined $log_entry->{commit_name})
+						? $log_entry->{commit_name}
+						: $log_entry->{name};
+	$ENV{GIT_COMMITTER_EMAIL} = (defined $log_entry->{commit_email})
+						? $log_entry->{commit_email}
+						: $log_entry->{email};
+	\%env;
+}
+
+sub restore_commit_header_env {
+	my ($env) = @_;
+	foreach my $ned (qw/NAME EMAIL DATE/) {
+		foreach my $ac (qw/AUTHOR COMMITTER/) {
+			my $k = "GIT_${ac}_${ned}";
+			if (defined $env->{$k}) {
+				$ENV{$k} = $env->{$k};
+			} else {
+				delete $ENV{$k};
+			}
+		}
+	}
+}
+
+sub gc {
+	command_noisy('gc', '--auto');
+};
+
+sub do_git_commit {
+	my ($self, $log_entry) = @_;
+	my $lr = $self->last_rev;
+	if (defined $lr && $lr >= $log_entry->{revision}) {
+		die "Last fetched revision of ", $self->refname,
+		    " was r$lr, but we are about to fetch: ",
+		    "r$log_entry->{revision}!\n";
+	}
+	if (my $c = $self->rev_map_get($log_entry->{revision})) {
+		croak "$log_entry->{revision} = $c already exists! ",
+		      "Why are we refetching it?\n";
+	}
+	my $old_env = set_commit_header_env($log_entry);
+	my $tree = $log_entry->{tree};
+	if (!defined $tree) {
+		$tree = $self->tmp_index_do(sub {
+		                            command_oneline('write-tree') });
+	}
+	die "Tree is not a valid sha1: $tree\n" if $tree !~ /^$::sha1$/o;
+
+	my @exec = ('git', 'commit-tree', $tree);
+	foreach ($self->get_commit_parents($log_entry)) {
+		push @exec, '-p', $_;
+	}
+	defined(my $pid = open3(my $msg_fh, my $out_fh, '>&STDERR', @exec))
+	                                                           or croak $!;
+	binmode $msg_fh;
+
+	# we always get UTF-8 from SVN, but we may want our commits in
+	# a different encoding.
+	if (my $enc = Git::config('i18n.commitencoding')) {
+		require Encode;
+		Encode::from_to($log_entry->{log}, 'UTF-8', $enc);
+	}
+	print $msg_fh $log_entry->{log} or croak $!;
+	restore_commit_header_env($old_env);
+	unless ($self->no_metadata) {
+		print $msg_fh "\ngit-svn-id: $log_entry->{metadata}\n"
+		              or croak $!;
+	}
+	$msg_fh->flush == 0 or croak $!;
+	close $msg_fh or croak $!;
+	chomp(my $commit = do { local $/; <$out_fh> });
+	close $out_fh or croak $!;
+	waitpid $pid, 0;
+	croak $? if $?;
+	if ($commit !~ /^$::sha1$/o) {
+		die "Failed to commit, invalid sha1: $commit\n";
+	}
+
+	$self->rev_map_set($log_entry->{revision}, $commit, 1);
+
+	$self->{last_rev} = $log_entry->{revision};
+	$self->{last_commit} = $commit;
+	print "r$log_entry->{revision}" unless $::_q > 1;
+	if (defined $log_entry->{svm_revision}) {
+		 print " (\@$log_entry->{svm_revision})" unless $::_q > 1;
+		 $self->rev_map_set($log_entry->{svm_revision}, $commit,
+		                   0, $self->svm_uuid);
+	}
+	print " = $commit ($self->{ref_id})\n" unless $::_q > 1;
+	if (--$_gc_nr == 0) {
+		$_gc_nr = $_gc_period;
+		gc();
+	}
+	return $commit;
+}
+
+sub match_paths {
+	my ($self, $paths, $r) = @_;
+	return 1 if $self->path eq '';
+	if (my $path = $paths->{"/".$self->path}) {
+		return ($path->{action} eq 'D') ? 0 : 1;
+	}
+	$self->{path_regex} ||= qr{^/\Q@{[$self->path]}\E/};
+	if (grep /$self->{path_regex}/, keys %$paths) {
+		return 1;
+	}
+	my $c = '';
+	foreach (split m#/#, $self->path) {
+		$c .= "/$_";
+		next unless ($paths->{$c} &&
+		             ($paths->{$c}->{action} =~ /^[AR]$/));
+		if ($self->ra->check_path($self->path, $r) ==
+		    $SVN::Node::dir) {
+			return 1;
+		}
+	}
+	return 0;
+}
+
+sub find_parent_branch {
+	my ($self, $paths, $rev) = @_;
+	return undef unless $self->follow_parent;
+	unless (defined $paths) {
+		my $err_handler = $SVN::Error::handler;
+		$SVN::Error::handler = \&Git::SVN::Ra::skip_unknown_revs;
+		$self->ra->get_log([$self->path], $rev, $rev, 0, 1, 1,
+				   sub { $paths = $_[0] });
+		$SVN::Error::handler = $err_handler;
+	}
+	return undef unless defined $paths;
+
+	# look for a parent from another branch:
+	my @b_path_components = split m#/#, $self->path;
+	my @a_path_components;
+	my $i;
+	while (@b_path_components) {
+		$i = $paths->{'/'.join('/', @b_path_components)};
+		last if $i && defined $i->{copyfrom_path};
+		unshift(@a_path_components, pop(@b_path_components));
+	}
+	return undef unless defined $i && defined $i->{copyfrom_path};
+	my $branch_from = $i->{copyfrom_path};
+	if (@a_path_components) {
+		print STDERR "branch_from: $branch_from => ";
+		$branch_from .= '/'.join('/', @a_path_components);
+		print STDERR $branch_from, "\n";
+	}
+	my $r = $i->{copyfrom_rev};
+	my $repos_root = $self->ra->{repos_root};
+	my $url = $self->ra->url;
+	my $new_url = canonicalize_url( add_path_to_url( $url, $branch_from ) );
+	print STDERR  "Found possible branch point: ",
+	              "$new_url => ", $self->full_url, ", $r\n"
+	              unless $::_q > 1;
+	$branch_from =~ s#^/##;
+	my $gs = $self->other_gs($new_url, $url,
+		                 $branch_from, $r, $self->{ref_id});
+	my ($r0, $parent) = $gs->find_rev_before($r, 1);
+	{
+		my ($base, $head);
+		if (!defined $r0 || !defined $parent) {
+			($base, $head) = parse_revision_argument(0, $r);
+		} else {
+			if ($r0 < $r) {
+				$gs->ra->get_log([$gs->path], $r0 + 1, $r, 1,
+					0, 1, sub { $base = $_[1] - 1 });
+			}
+		}
+		if (defined $base && $base <= $r) {
+			$gs->fetch($base, $r);
+		}
+		($r0, $parent) = $gs->find_rev_before($r, 1);
+	}
+	if (defined $r0 && defined $parent) {
+		print STDERR "Found branch parent: ($self->{ref_id}) $parent\n"
+		             unless $::_q > 1;
+		my $ed;
+		if ($self->ra->can_do_switch) {
+			$self->assert_index_clean($parent);
+			print STDERR "Following parent with do_switch\n"
+			             unless $::_q > 1;
+			# do_switch works with svn/trunk >= r22312, but that
+			# is not included with SVN 1.4.3 (the latest version
+			# at the moment), so we can't rely on it
+			$self->{last_rev} = $r0;
+			$self->{last_commit} = $parent;
+			$ed = Git::SVN::Fetcher->new($self, $gs->path);
+			$gs->ra->gs_do_switch($r0, $rev, $gs,
+					      $self->full_url, $ed)
+			  or die "SVN connection failed somewhere...\n";
+		} elsif ($self->ra->trees_match($new_url, $r0,
+			                        $self->full_url, $rev)) {
+			print STDERR "Trees match:\n",
+			             "  $new_url\@$r0\n",
+			             "  ${\$self->full_url}\@$rev\n",
+			             "Following parent with no changes\n"
+			             unless $::_q > 1;
+			$self->tmp_index_do(sub {
+			    command_noisy('read-tree', $parent);
+			});
+			$self->{last_commit} = $parent;
+		} else {
+			print STDERR "Following parent with do_update\n"
+			             unless $::_q > 1;
+			$ed = Git::SVN::Fetcher->new($self);
+			$self->ra->gs_do_update($rev, $rev, $self, $ed)
+			  or die "SVN connection failed somewhere...\n";
+		}
+		print STDERR "Successfully followed parent\n" unless $::_q > 1;
+		return $self->make_log_entry($rev, [$parent], $ed, $r0, $branch_from);
+	}
+	return undef;
+}
+
+sub do_fetch {
+	my ($self, $paths, $rev) = @_;
+	my $ed;
+	my ($last_rev, @parents);
+	if (my $lc = $self->last_commit) {
+		# we can have a branch that was deleted, then re-added
+		# under the same name but copied from another path, in
+		# which case we'll have multiple parents (we don't
+		# want to break the original ref or lose copypath info):
+		if (my $log_entry = $self->find_parent_branch($paths, $rev)) {
+			push @{$log_entry->{parents}}, $lc;
+			return $log_entry;
+		}
+		$ed = Git::SVN::Fetcher->new($self);
+		$last_rev = $self->{last_rev};
+		$ed->{c} = $lc;
+		@parents = ($lc);
+	} else {
+		$last_rev = $rev;
+		if (my $log_entry = $self->find_parent_branch($paths, $rev)) {
+			return $log_entry;
+		}
+		$ed = Git::SVN::Fetcher->new($self);
+	}
+	unless ($self->ra->gs_do_update($last_rev, $rev, $self, $ed)) {
+		die "SVN connection failed somewhere...\n";
+	}
+	$self->make_log_entry($rev, \@parents, $ed, $last_rev, $self->path);
+}
+
+sub mkemptydirs {
+	my ($self, $r) = @_;
+
+	# add/remove/collect a paths table
+	#
+	# Paths are split into a tree of nodes, stored as a hash of hashes.
+	#
+	# Each node contains a 'path' entry for the path (if any) associated
+	# with that node and a 'children' entry for any nodes under that
+	# location.
+	#
+	# Removing a path requires a hash lookup for each component then
+	# dropping that node (and anything under it), which is substantially
+	# faster than a grep slice into a single hash of paths for large
+	# numbers of paths.
+	#
+	# For a large (200K) number of empty_dir directives this reduces
+	# scanning time to 3 seconds vs 10 minutes for grep+delete on a single
+	# hash of paths.
+	sub add_path {
+		my ($paths_table, $path) = @_;
+		my $node_ref;
+
+		foreach my $x (split('/', $path)) {
+			if (!exists($paths_table->{$x})) {
+				$paths_table->{$x} = { children => {} };
+			}
+
+			$node_ref = $paths_table->{$x};
+			$paths_table = $paths_table->{$x}->{children};
+		}
+
+		$node_ref->{path} = $path;
+	}
+
+	sub remove_path {
+		my ($paths_table, $path) = @_;
+		my $nodes_ref;
+		my $node_name;
+
+		foreach my $x (split('/', $path)) {
+			if (!exists($paths_table->{$x})) {
+				return;
+			}
+
+			$nodes_ref = $paths_table;
+			$node_name = $x;
+
+			$paths_table = $paths_table->{$x}->{children};
+		}
+
+		delete($nodes_ref->{$node_name});
+	}
+
+	sub collect_paths {
+		my ($paths_table, $paths_ref) = @_;
+
+		foreach my $v (values %$paths_table) {
+			my $p = $v->{path};
+			my $c = $v->{children};
+
+			collect_paths($c, $paths_ref);
+
+			if (defined($p)) {
+				push(@$paths_ref, $p);
+			}
+		}
+	}
+
+	sub scan {
+		my ($r, $paths_table, $line) = @_;
+		if (defined $r && $line =~ /^r(\d+)$/) {
+			return 0 if $1 > $r;
+		} elsif ($line =~ /^  \+empty_dir: (.+)$/) {
+			add_path($paths_table, $1);
+		} elsif ($line =~ /^  \-empty_dir: (.+)$/) {
+			remove_path($paths_table, $1);
+		}
+		1; # continue
+	};
+
+	my @empty_dirs;
+	my %paths_table;
+
+	my $gz_file = "$self->{dir}/unhandled.log.gz";
+	if (-f $gz_file) {
+		if (!can_compress()) {
+			warn "Compress::Zlib could not be found; ",
+			     "empty directories in $gz_file will not be read\n";
+		} else {
+			my $gz = Compress::Zlib::gzopen($gz_file, "rb") or
+				die "Unable to open $gz_file: $!\n";
+			my $line;
+			while ($gz->gzreadline($line) > 0) {
+				scan($r, \%paths_table, $line) or last;
+			}
+			$gz->gzclose;
+		}
+	}
+
+	if (open my $fh, '<', "$self->{dir}/unhandled.log") {
+		binmode $fh or croak "binmode: $!";
+		while (<$fh>) {
+			scan($r, \%paths_table, $_) or last;
+		}
+		close $fh;
+	}
+
+	collect_paths(\%paths_table, \@empty_dirs);
+	my $strip = qr/\A\Q@{[$self->path]}\E(?:\/|$)/;
+	foreach my $d (sort @empty_dirs) {
+		$d = uri_decode($d);
+		$d =~ s/$strip//;
+		next unless length($d);
+		next if -d $d;
+		if (-e $d) {
+			warn "$d exists but is not a directory\n";
+		} else {
+			print "creating empty directory: $d\n";
+			mkpath([$d]);
+		}
+	}
+}
+
+sub get_untracked {
+	my ($self, $ed) = @_;
+	my @out;
+	my $h = $ed->{empty};
+	foreach (sort keys %$h) {
+		my $act = $h->{$_} ? '+empty_dir' : '-empty_dir';
+		push @out, "  $act: " . uri_encode($_);
+		warn "W: $act: $_\n";
+	}
+	foreach my $t (qw/dir_prop file_prop/) {
+		$h = $ed->{$t} or next;
+		foreach my $path (sort keys %$h) {
+			my $ppath = $path eq '' ? '.' : $path;
+			foreach my $prop (sort keys %{$h->{$path}}) {
+				next if $SKIP_PROP{$prop};
+				my $v = $h->{$path}->{$prop};
+				my $t_ppath_prop = "$t: " .
+				                    uri_encode($ppath) . ' ' .
+				                    uri_encode($prop);
+				if (defined $v) {
+					push @out, "  +$t_ppath_prop " .
+					           uri_encode($v);
+				} else {
+					push @out, "  -$t_ppath_prop";
+				}
+			}
+		}
+	}
+	foreach my $t (qw/absent_file absent_directory/) {
+		$h = $ed->{$t} or next;
+		foreach my $parent (sort keys %$h) {
+			foreach my $path (sort @{$h->{$parent}}) {
+				push @out, "  $t: " .
+				           uri_encode("$parent/$path");
+				warn "W: $t: $parent/$path ",
+				     "Insufficient permissions?\n";
+			}
+		}
+	}
+	\@out;
+}
+
+# parse_svn_date(DATE)
+# --------------------
+# Given a date (in UTC) from Subversion, return a string in the format
+# "<TZ Offset> <local date/time>" that Git will use.
+#
+# By default the parsed date will be in UTC; if $Git::SVN::_localtime
+# is true we'll convert it to the local timezone instead.
+sub parse_svn_date {
+	my $date = shift || return '+0000 1970-01-01 00:00:00';
+	my ($Y,$m,$d,$H,$M,$S) = ($date =~ /^(\d{4})\-(\d\d)\-(\d\d)T
+	                                    (\d\d?)\:(\d\d)\:(\d\d)\.\d*Z$/x) or
+	                                 croak "Unable to parse date: $date\n";
+	my $parsed_date;    # Set next.
+
+	if ($Git::SVN::_localtime) {
+		# Translate the Subversion datetime to an epoch time.
+		# Begin by switching ourselves to $date's timezone, UTC.
+		my $old_env_TZ = $ENV{TZ};
+		$ENV{TZ} = 'UTC';
+
+		my $epoch_in_UTC =
+		    Time::Local::timelocal($S, $M, $H, $d, $m - 1, $Y);
+
+		# Determine our local timezone (including DST) at the
+		# time of $epoch_in_UTC.  $Git::SVN::Log::TZ stored the
+		# value of TZ, if any, at the time we were run.
+		if (defined $Git::SVN::Log::TZ) {
+			$ENV{TZ} = $Git::SVN::Log::TZ;
+		} else {
+			delete $ENV{TZ};
+		}
+
+		my $our_TZ = get_tz_offset($epoch_in_UTC);
+
+		# This converts $epoch_in_UTC into our local timezone.
+		my ($sec, $min, $hour, $mday, $mon, $year,
+		    $wday, $yday, $isdst) = localtime($epoch_in_UTC);
+
+		$parsed_date = sprintf('%s %04d-%02d-%02d %02d:%02d:%02d',
+				       $our_TZ, $year + 1900, $mon + 1,
+				       $mday, $hour, $min, $sec);
+
+		# Reset us to the timezone in effect when we entered
+		# this routine.
+		if (defined $old_env_TZ) {
+			$ENV{TZ} = $old_env_TZ;
+		} else {
+			delete $ENV{TZ};
+		}
+	} else {
+		$parsed_date = "+0000 $Y-$m-$d $H:$M:$S";
+	}
+
+	return $parsed_date;
+}
+
+sub other_gs {
+	my ($self, $new_url, $url,
+	    $branch_from, $r, $old_ref_id) = @_;
+	my $gs = Git::SVN->find_by_url($new_url, $url, $branch_from);
+	unless ($gs) {
+		my $ref_id = $old_ref_id;
+		$ref_id =~ s/\@\d+-*$//;
+		$ref_id .= "\@$r";
+		# just grow a tail if we're not unique enough :x
+		$ref_id .= '-' while find_ref($ref_id);
+		my ($u, $p, $repo_id) = ($new_url, '', $ref_id);
+		if ($u =~ s#^\Q$url\E(/|$)##) {
+			$p = $u;
+			$u = $url;
+			$repo_id = $self->{repo_id};
+		}
+		while (1) {
+			# It is possible to tag two different subdirectories at
+			# the same revision.  If the url for an existing ref
+			# does not match, we must either find a ref with a
+			# matching url or create a new ref by growing a tail.
+			$gs = Git::SVN->init($u, $p, $repo_id, $ref_id, 1);
+			my (undef, $max_commit) = $gs->rev_map_max(1);
+			last if (!$max_commit);
+			my ($url) = ::cmt_metadata($max_commit);
+			last if ($url eq $gs->metadata_url);
+			$ref_id .= '-';
+		}
+		print STDERR "Initializing parent: $ref_id\n" unless $::_q > 1;
+	}
+	$gs
+}
+
+sub call_authors_prog {
+	my ($orig_author) = @_;
+	$orig_author = command_oneline('rev-parse', '--sq-quote', $orig_author);
+	my $author = `$::_authors_prog $orig_author`;
+	if ($? != 0) {
+		die "$::_authors_prog failed with exit code $?\n"
+	}
+	if ($author =~ /^\s*(.+?)\s*<(.*)>\s*$/) {
+		my ($name, $email) = ($1, $2);
+		return [$name, $email];
+	} else {
+		die "Author: $orig_author: $::_authors_prog returned "
+			. "invalid author format: $author\n";
+	}
+}
+
+sub check_author {
+	my ($author) = @_;
+	if (!defined $author || length $author == 0) {
+		$author = '(no author)';
+	}
+	if (!defined $::users{$author}) {
+		if (defined $::_authors_prog) {
+			$::users{$author} = call_authors_prog($author);
+		} elsif (defined $::_authors) {
+			die "Author: $author not defined in $::_authors file\n";
+		}
+	}
+	$author;
+}
+
+sub find_extra_svk_parents {
+	my ($self, $tickets, $parents) = @_;
+	# aha!  svk:merge property changed...
+	my @tickets = split "\n", $tickets;
+	my @known_parents;
+	for my $ticket ( @tickets ) {
+		my ($uuid, $path, $rev) = split /:/, $ticket;
+		if ( $uuid eq $self->ra_uuid ) {
+			my $repos_root = $self->url;
+			my $branch_from = $path;
+			$branch_from =~ s{^/}{};
+			my $gs = $self->other_gs(add_path_to_url( $repos_root, $branch_from ),
+			                         $repos_root,
+			                         $branch_from,
+			                         $rev,
+			                         $self->{ref_id});
+			if ( my $commit = $gs->rev_map_get($rev, $uuid) ) {
+				# wahey!  we found it, but it might be
+				# an old one (!)
+				push @known_parents, [ $rev, $commit ];
+			}
+		}
+	}
+	# Ordering matters; highest-numbered commit merge tickets
+	# first, as they may account for later merge ticket additions
+	# or changes.
+	@known_parents = map {$_->[1]} sort {$b->[0] <=> $a->[0]} @known_parents;
+	for my $parent ( @known_parents ) {
+		my @cmd = ('rev-list', $parent, map { "^$_" } @$parents );
+		my ($msg_fh, $ctx) = command_output_pipe(@cmd);
+		my $new;
+		while ( <$msg_fh> ) {
+			$new=1;last;
+		}
+		command_close_pipe($msg_fh, $ctx);
+		if ( $new ) {
+			print STDERR
+			    "Found merge parent (svk:merge ticket): $parent\n";
+			push @$parents, $parent;
+		}
+	}
+}
+
+sub lookup_svn_merge {
+	my $uuid = shift;
+	my $url = shift;
+	my $source = shift;
+	my $revs = shift;
+
+	my $path = $source;
+	$path =~ s{^/}{};
+	my $gs = Git::SVN->find_by_url($url.$source, $url, $path);
+	if ( !$gs ) {
+		warn "Couldn't find revmap for $url$source\n";
+		return;
+	}
+	my @ranges = split ",", $revs;
+	my ($tip, $tip_commit);
+	my @merged_commit_ranges;
+	# find the tip
+	for my $range ( @ranges ) {
+		if ($range =~ /[*]$/) {
+			warn "W: Ignoring partial merge in svn:mergeinfo "
+				."dirprop: $source:$range\n";
+			next;
+		}
+		my ($bottom, $top) = split "-", $range;
+		$top ||= $bottom;
+		my $bottom_commit = $gs->find_rev_after( $bottom, 1, $top );
+		my $top_commit = $gs->find_rev_before( $top, 1, $bottom );
+
+		unless ($top_commit and $bottom_commit) {
+			warn "W: unknown path/rev in svn:mergeinfo "
+				."dirprop: $source:$range\n";
+			next;
+		}
+
+		if (scalar(command('rev-parse', "$bottom_commit^@"))) {
+			push @merged_commit_ranges,
+			     "$bottom_commit^..$top_commit";
+		} else {
+			push @merged_commit_ranges, "$top_commit";
+		}
+
+		if ( !defined $tip or $top > $tip ) {
+			$tip = $top;
+			$tip_commit = $top_commit;
+		}
+	}
+	return ($tip_commit, @merged_commit_ranges);
+}
+
+sub _rev_list {
+	my ($msg_fh, $ctx) = command_output_pipe(
+		"rev-list", @_,
+	       );
+	my @rv;
+	while ( <$msg_fh> ) {
+		chomp;
+		push @rv, $_;
+	}
+	command_close_pipe($msg_fh, $ctx);
+	@rv;
+}
+
+sub check_cherry_pick2 {
+	my $base = shift;
+	my $tip = shift;
+	my $parents = shift;
+	my @ranges = @_;
+	my %commits = map { $_ => 1 }
+		_rev_list("--no-merges", $tip, "--not", $base, @$parents, "--");
+	for my $range ( @ranges ) {
+		delete @commits{_rev_list($range, "--")};
+	}
+	for my $commit (keys %commits) {
+		if (has_no_changes($commit)) {
+			delete $commits{$commit};
+		}
+	}
+	my @k = (keys %commits);
+	return (scalar @k, $k[0]);
+}
+
+sub has_no_changes {
+	my $commit = shift;
+
+	my @revs = split / /, command_oneline(
+		qw(rev-list --parents -1 -m), $commit);
+
+	# Commits with no parents, e.g. the start of a partial branch,
+	# have changes by definition.
+	return 1 if (@revs < 2);
+
+	# Commits with multiple parents, e.g a merge, have no changes
+	# by definition.
+	return 0 if (@revs > 2);
+
+	return (command_oneline("rev-parse", "$commit^{tree}") eq
+		command_oneline("rev-parse", "$commit~1^{tree}"));
+}
+
+sub tie_for_persistent_memoization {
+	my $hash = shift;
+	my $path = shift;
+
+	unless ($memo_backend) {
+		if (eval { require Git::SVN::Memoize::YAML; 1}) {
+			$memo_backend = 1;
+		} else {
+			require Memoize::Storable;
+			$memo_backend = -1;
+		}
+	}
+
+	if ($memo_backend > 0) {
+		tie %$hash => 'Git::SVN::Memoize::YAML', "$path.yaml";
+	} else {
+		# first verify that any existing file can actually be loaded
+		# (it may have been saved by an incompatible version)
+		my $db = "$path.db";
+		if (-e $db) {
+			use Storable qw(retrieve);
+
+			if (!eval { retrieve($db); 1 }) {
+				unlink $db or die "unlink $db failed: $!";
+			}
+		}
+		tie %$hash => 'Memoize::Storable', $db, 'nstore';
+	}
+}
+
+# The GIT_DIR environment variable is not always set until after the command
+# line arguments are processed, so we can't memoize in a BEGIN block.
+{
+	my $memoized = 0;
+
+	sub memoize_svn_mergeinfo_functions {
+		return if $memoized;
+		$memoized = 1;
+
+		my $cache_path = svn_dir() . '/.caches/';
+		mkpath([$cache_path]) unless -d $cache_path;
+
+		my %lookup_svn_merge_cache;
+		my %check_cherry_pick2_cache;
+		my %has_no_changes_cache;
+
+		tie_for_persistent_memoization(\%lookup_svn_merge_cache,
+		    "$cache_path/lookup_svn_merge");
+		memoize 'lookup_svn_merge',
+			SCALAR_CACHE => 'FAULT',
+			LIST_CACHE => ['HASH' => \%lookup_svn_merge_cache],
+		;
+
+		tie_for_persistent_memoization(\%check_cherry_pick2_cache,
+		    "$cache_path/check_cherry_pick2");
+		memoize 'check_cherry_pick2',
+			SCALAR_CACHE => 'FAULT',
+			LIST_CACHE => ['HASH' => \%check_cherry_pick2_cache],
+		;
+
+		tie_for_persistent_memoization(\%has_no_changes_cache,
+		    "$cache_path/has_no_changes");
+		memoize 'has_no_changes',
+			SCALAR_CACHE => ['HASH' => \%has_no_changes_cache],
+			LIST_CACHE => 'FAULT',
+		;
+	}
+
+	sub unmemoize_svn_mergeinfo_functions {
+		return if not $memoized;
+		$memoized = 0;
+
+		Memoize::unmemoize 'lookup_svn_merge';
+		Memoize::unmemoize 'check_cherry_pick2';
+		Memoize::unmemoize 'has_no_changes';
+	}
+
+	sub clear_memoized_mergeinfo_caches {
+		die "Only call this method in non-memoized context" if ($memoized);
+
+		my $cache_path = svn_dir() . '/.caches/';
+		return unless -d $cache_path;
+
+		for my $cache_file (("$cache_path/lookup_svn_merge",
+				     "$cache_path/check_cherry_pick", # old
+				     "$cache_path/check_cherry_pick2",
+				     "$cache_path/has_no_changes")) {
+			for my $suffix (qw(yaml db)) {
+				my $file = "$cache_file.$suffix";
+				next unless -e $file;
+				unlink($file) or die "unlink($file) failed: $!\n";
+			}
+		}
+	}
+
+
+	Memoize::memoize 'Git::SVN::repos_root';
+}
+
+END {
+	# Force cache writeout explicitly instead of waiting for
+	# global destruction to avoid segfault in Storable:
+	# http://rt.cpan.org/Public/Bug/Display.html?id=36087
+	unmemoize_svn_mergeinfo_functions();
+}
+
+sub parents_exclude {
+	my $parents = shift;
+	my @commits = @_;
+	return unless @commits;
+
+	my @excluded;
+	my $excluded;
+	do {
+		my @cmd = ('rev-list', "-1", @commits, "--not", @$parents );
+		$excluded = command_oneline(@cmd);
+		if ( $excluded ) {
+			my @new;
+			my $found;
+			for my $commit ( @commits ) {
+				if ( $commit eq $excluded ) {
+					push @excluded, $commit;
+					$found++;
+				}
+				else {
+					push @new, $commit;
+				}
+			}
+			die "saw commit '$excluded' in rev-list output, "
+				."but we didn't ask for that commit (wanted: @commits --not @$parents)"
+					unless $found;
+			@commits = @new;
+		}
+	}
+		while ($excluded and @commits);
+
+	return @excluded;
+}
+
+# Compute what's new in svn:mergeinfo.
+sub mergeinfo_changes {
+	my ($self, $old_path, $old_rev, $path, $rev, $mergeinfo_prop) = @_;
+	my %minfo = map {split ":", $_ } split "\n", $mergeinfo_prop;
+	my $old_minfo = {};
+
+	my $ra = $self->ra;
+	# Give up if $old_path isn't in the repo.
+	# This is probably a merge on a subtree.
+	if ($ra->check_path($old_path, $old_rev) != $SVN::Node::dir) {
+		warn "W: ignoring svn:mergeinfo on $old_path, ",
+			"directory didn't exist in r$old_rev\n";
+		return {};
+	}
+	my (undef, undef, $props) = $ra->get_dir($old_path, $old_rev);
+	if (defined $props->{"svn:mergeinfo"}) {
+		my %omi = map {split ":", $_ } split "\n",
+			$props->{"svn:mergeinfo"};
+		$old_minfo = \%omi;
+	}
+
+	my %changes = ();
+	foreach my $p (keys %minfo) {
+		my $a = $old_minfo->{$p} || "";
+		my $b = $minfo{$p};
+		# Omit merged branches whose ranges lists are unchanged.
+		next if $a eq $b;
+		# Remove any common range list prefix.
+		($a ^ $b) =~ /^[\0]*/;
+		my $common_prefix = rindex $b, ",", $+[0] - 1;
+		$changes{$p} = substr $b, $common_prefix + 1;
+	}
+	print STDERR "Checking svn:mergeinfo changes since r$old_rev: ",
+		scalar(keys %minfo), " sources, ",
+		scalar(keys %changes), " changed\n";
+
+	return \%changes;
+}
+
+# note: this function should only be called if the various dirprops
+# have actually changed
+sub find_extra_svn_parents {
+	my ($self, $mergeinfo, $parents) = @_;
+	# aha!  svk:merge property changed...
+
+	memoize_svn_mergeinfo_functions();
+
+	# We first search for merged tips which are not in our
+	# history.  Then, we figure out which git revisions are in
+	# that tip, but not this revision.  If all of those revisions
+	# are now marked as merge, we can add the tip as a parent.
+	my @merges = sort keys %$mergeinfo;
+	my @merge_tips;
+	my $url = $self->url;
+	my $uuid = $self->ra_uuid;
+	my @all_ranges;
+	for my $merge ( @merges ) {
+		my ($tip_commit, @ranges) =
+			lookup_svn_merge( $uuid, $url,
+					  $merge, $mergeinfo->{$merge} );
+		unless (!$tip_commit or
+				grep { $_ eq $tip_commit } @$parents ) {
+			push @merge_tips, $tip_commit;
+			push @all_ranges, @ranges;
+		} else {
+			push @merge_tips, undef;
+		}
+	}
+
+	my %excluded = map { $_ => 1 }
+		parents_exclude($parents, grep { defined } @merge_tips);
+
+	# check merge tips for new parents
+	my @new_parents;
+	for my $merge_tip ( @merge_tips ) {
+		my $merge = shift @merges;
+		next unless $merge_tip and $excluded{$merge_tip};
+		my $spec = "$merge:$mergeinfo->{$merge}";
+
+		# check out 'new' tips
+		my $merge_base;
+		eval {
+			$merge_base = command_oneline(
+				"merge-base",
+				@$parents, $merge_tip,
+			);
+		};
+		if ($@) {
+			die "An error occurred during merge-base"
+				unless $@->isa("Git::Error::Command");
+
+			warn "W: Cannot find common ancestor between ".
+			     "@$parents and $merge_tip. Ignoring merge info.\n";
+			next;
+		}
+
+		# double check that there are no missing non-merge commits
+		my ($ninc, $ifirst) = check_cherry_pick2(
+			$merge_base, $merge_tip,
+			$parents,
+			@all_ranges,
+		       );
+
+		if ($ninc) {
+			warn "W: svn cherry-pick ignored ($spec) - missing " .
+				"$ninc commit(s) (eg $ifirst)\n";
+		} else {
+			warn "Found merge parent ($spec): ", $merge_tip, "\n";
+			push @new_parents, $merge_tip;
+		}
+	}
+
+	# cater for merges which merge commits from multiple branches
+	if ( @new_parents > 1 ) {
+		for ( my $i = 0; $i <= $#new_parents; $i++ ) {
+			for ( my $j = 0; $j <= $#new_parents; $j++ ) {
+				next if $i == $j;
+				next unless $new_parents[$i];
+				next unless $new_parents[$j];
+				my $revs = command_oneline(
+					"rev-list", "-1",
+					"$new_parents[$i]..$new_parents[$j]",
+				       );
+				if ( !$revs ) {
+					undef($new_parents[$j]);
+				}
+			}
+		}
+	}
+	push @$parents, grep { defined } @new_parents;
+}
+
+sub make_log_entry {
+	my ($self, $rev, $parents, $ed, $parent_rev, $parent_path) = @_;
+	my $untracked = $self->get_untracked($ed);
+
+	my @parents = @$parents;
+	my $props = $ed->{dir_prop}{$self->path};
+	if ($self->follow_parent) {
+		my $tickets = $props->{"svk:merge"};
+		if ($tickets) {
+			$self->find_extra_svk_parents($tickets, \@parents);
+		}
+
+		my $mergeinfo_prop = $props->{"svn:mergeinfo"};
+		if ($mergeinfo_prop) {
+			my $mi_changes = $self->mergeinfo_changes(
+						$parent_path,
+						$parent_rev,
+						$self->path,
+						$rev,
+						$mergeinfo_prop);
+			$self->find_extra_svn_parents($mi_changes, \@parents);
+		}
+	}
+
+	open my $un, '>>', "$self->{dir}/unhandled.log" or croak $!;
+	print $un "r$rev\n" or croak $!;
+	print $un $_, "\n" foreach @$untracked;
+	my %log_entry = ( parents => \@parents, revision => $rev,
+	                  log => '');
+
+	my $headrev;
+	my $logged = delete $self->{logged_rev_props};
+	if (!$logged || $self->{-want_revprops}) {
+		my $rp = $self->ra->rev_proplist($rev);
+		foreach (sort keys %$rp) {
+			my $v = $rp->{$_};
+			if (/^svn:(author|date|log)$/) {
+				$log_entry{$1} = $v;
+			} elsif ($_ eq 'svm:headrev') {
+				$headrev = $v;
+			} else {
+				print $un "  rev_prop: ", uri_encode($_), ' ',
+					  uri_encode($v), "\n";
+			}
+		}
+	} else {
+		map { $log_entry{$_} = $logged->{$_} } keys %$logged;
+	}
+	close $un or croak $!;
+
+	$log_entry{date} = parse_svn_date($log_entry{date});
+	$log_entry{log} .= "\n";
+	my $author = $log_entry{author} = check_author($log_entry{author});
+	my ($name, $email) = defined $::users{$author} ? @{$::users{$author}}
+						       : ($author, undef);
+
+	my ($commit_name, $commit_email) = ($name, $email);
+	if ($_use_log_author) {
+		my $name_field;
+		if ($log_entry{log} =~ /From:\s+(.*\S)\s*\n/i) {
+			$name_field = $1;
+		} elsif ($log_entry{log} =~ /Signed-off-by:\s+(.*\S)\s*\n/i) {
+			$name_field = $1;
+		}
+		if (!defined $name_field) {
+			if (!defined $email) {
+				$email = $name;
+			}
+		} elsif ($name_field =~ /(.*?)\s+<(.*)>/) {
+			($name, $email) = ($1, $2);
+		} elsif ($name_field =~ /(.*)@/) {
+			($name, $email) = ($1, $name_field);
+		} else {
+			($name, $email) = ($name_field, $name_field);
+		}
+	}
+	if (defined $headrev && $self->use_svm_props) {
+		if ($self->rewrite_root) {
+			die "Can't have both 'useSvmProps' and 'rewriteRoot' ",
+			    "options set!\n";
+		}
+		if ($self->rewrite_uuid) {
+			die "Can't have both 'useSvmProps' and 'rewriteUUID' ",
+			    "options set!\n";
+		}
+		my ($uuid, $r) = $headrev =~ m{^([a-f\d\-]{30,}):(\d+)$}i;
+		# we don't want "SVM: initializing mirror for junk" ...
+		return undef if $r == 0;
+		my $svm = $self->svm;
+		if ($uuid ne $svm->{uuid}) {
+			die "UUID mismatch on SVM path:\n",
+			    "expected: $svm->{uuid}\n",
+			    "     got: $uuid\n";
+		}
+		my $full_url = $self->full_url;
+		$full_url =~ s#^\Q$svm->{replace}\E(/|$)#$svm->{source}$1# or
+		             die "Failed to replace '$svm->{replace}' with ",
+		                 "'$svm->{source}' in $full_url\n";
+		# throw away username for storing in records
+		remove_username($full_url);
+		$log_entry{metadata} = "$full_url\@$r $uuid";
+		$log_entry{svm_revision} = $r;
+		$email = "$author\@$uuid" unless defined $email;
+		$commit_email = "$author\@$uuid" unless defined $commit_email;
+	} elsif ($self->use_svnsync_props) {
+		my $full_url = canonicalize_url(
+			add_path_to_url( $self->svnsync->{url}, $self->path )
+		);
+		remove_username($full_url);
+		my $uuid = $self->svnsync->{uuid};
+		$log_entry{metadata} = "$full_url\@$rev $uuid";
+		$email = "$author\@$uuid" unless defined $email;
+		$commit_email = "$author\@$uuid" unless defined $commit_email;
+	} else {
+		my $url = $self->metadata_url;
+		remove_username($url);
+		my $uuid = $self->rewrite_uuid || $self->ra->get_uuid;
+		$log_entry{metadata} = "$url\@$rev " . $uuid;
+		$email = "$author\@$uuid" unless defined $email;
+		$commit_email = "$author\@$uuid" unless defined $commit_email;
+	}
+	$log_entry{name} = $name;
+	$log_entry{email} = $email;
+	$log_entry{commit_name} = $commit_name;
+	$log_entry{commit_email} = $commit_email;
+	\%log_entry;
+}
+
+sub fetch {
+	my ($self, $min_rev, $max_rev, @parents) = @_;
+	my ($last_rev, $last_commit) = $self->last_rev_commit;
+	my ($base, $head) = $self->get_fetch_range($min_rev, $max_rev);
+	$self->ra->gs_fetch_loop_common($base, $head, [$self]);
+}
+
+sub set_tree_cb {
+	my ($self, $log_entry, $tree, $rev, $date, $author) = @_;
+	$self->{inject_parents} = { $rev => $tree };
+	$self->fetch(undef, undef);
+}
+
+sub set_tree {
+	my ($self, $tree) = (shift, shift);
+	my $log_entry = ::get_commit_entry($tree);
+	unless ($self->{last_rev}) {
+		fatal("Must have an existing revision to commit");
+	}
+	my %ed_opts = ( r => $self->{last_rev},
+	                log => $log_entry->{log},
+	                ra => $self->ra,
+	                tree_a => $self->{last_commit},
+	                tree_b => $tree,
+	                editor_cb => sub {
+			       $self->set_tree_cb($log_entry, $tree, @_) },
+	                svn_path => $self->path );
+	if (!Git::SVN::Editor->new(\%ed_opts)->apply_diff) {
+		print "No changes\nr$self->{last_rev} = $tree\n";
+	}
+}
+
+sub rebuild_from_rev_db {
+	my ($self, $path) = @_;
+	my $r = -1;
+	open my $fh, '<', $path or croak "open: $!";
+	binmode $fh or croak "binmode: $!";
+	while (<$fh>) {
+		length($_) == 41 or croak "inconsistent size in ($_) != 41";
+		chomp($_);
+		++$r;
+		next if $_ eq ('0' x 40);
+		$self->rev_map_set($r, $_);
+		print "r$r = $_\n";
+	}
+	close $fh or croak "close: $!";
+	unlink $path or croak "unlink: $!";
+}
+
+#define a global associate map to record rebuild status
+my %rebuild_status;
+#define a global associate map to record rebuild verify status
+my %rebuild_verify_status;
+
+sub rebuild {
+	my ($self) = @_;
+	my $map_path = $self->map_path;
+	my $partial = (-e $map_path && ! -z $map_path);
+	my $verify_key = $self->refname.'^0';
+	if (!$rebuild_verify_status{$verify_key}) {
+		my $verify_result = ::verify_ref($verify_key);
+		if ($verify_result) {
+			$rebuild_verify_status{$verify_key} = 1;
+		}
+	}
+	if (!$rebuild_verify_status{$verify_key}) {
+		return;
+	}
+	if (!$partial && ($self->use_svm_props || $self->no_metadata)) {
+		my $rev_db = $self->rev_db_path;
+		$self->rebuild_from_rev_db($rev_db);
+		if ($self->use_svm_props) {
+			my $svm_rev_db = $self->rev_db_path($self->svm_uuid);
+			$self->rebuild_from_rev_db($svm_rev_db);
+		}
+		$self->unlink_rev_db_symlink;
+		return;
+	}
+	print "Rebuilding $map_path ...\n" if (!$partial);
+	my ($base_rev, $head) = ($partial ? $self->rev_map_max_norebuild(1) :
+		(undef, undef));
+	my $key_value = ($head ? "$head.." : "") . $self->refname;
+	if (exists $rebuild_status{$key_value}) {
+		print "Done rebuilding $map_path\n" if (!$partial || !$head);
+		my $rev_db_path = $self->rev_db_path;
+		if (-f $self->rev_db_path) {
+			unlink $self->rev_db_path or croak "unlink: $!";
+		}
+		$self->unlink_rev_db_symlink;
+		return;
+	}
+	my ($log, $ctx) =
+		command_output_pipe(qw/rev-list --pretty=raw --reverse/,
+				$key_value,
+				'--');
+	$rebuild_status{$key_value} = 1;
+	my $metadata_url = $self->metadata_url;
+	remove_username($metadata_url);
+	my $svn_uuid = $self->rewrite_uuid || $self->ra_uuid;
+	my $c;
+	while (<$log>) {
+		if ( m{^commit ($::sha1)$} ) {
+			$c = $1;
+			next;
+		}
+		next unless s{^\s*(git-svn-id:)}{$1};
+		my ($url, $rev, $uuid) = ::extract_metadata($_);
+		remove_username($url);
+
+		# ignore merges (from set-tree)
+		next if (!defined $rev || !$uuid);
+
+		# if we merged or otherwise started elsewhere, this is
+		# how we break out of it
+		if (($uuid ne $svn_uuid) ||
+		    ($metadata_url && $url && ($url ne $metadata_url))) {
+			next;
+		}
+		if ($partial && $head) {
+			print "Partial-rebuilding $map_path ...\n";
+			print "Currently at $base_rev = $head\n";
+			$head = undef;
+		}
+
+		$self->rev_map_set($rev, $c);
+		print "r$rev = $c\n";
+	}
+	command_close_pipe($log, $ctx);
+	print "Done rebuilding $map_path\n" if (!$partial || !$head);
+	my $rev_db_path = $self->rev_db_path;
+	if (-f $self->rev_db_path) {
+		unlink $self->rev_db_path or croak "unlink: $!";
+	}
+	$self->unlink_rev_db_symlink;
+}
+
+# rev_map:
+# Tie::File seems to be prone to offset errors if revisions get sparse,
+# it's not that fast, either.  Tie::File is also not in Perl 5.6.  So
+# one of my favorite modules is out :<  Next up would be one of the DBM
+# modules, but I'm not sure which is most portable...
+#
+# This is the replacement for the rev_db format, which was too big
+# and inefficient for large repositories with a lot of sparse history
+# (mainly tags)
+#
+# The format is this:
+#   - 24 bytes for every record,
+#     * 4 bytes for the integer representing an SVN revision number
+#     * 20 bytes representing the sha1 of a git commit
+#   - No empty padding records like the old format
+#     (except the last record, which can be overwritten)
+#   - new records are written append-only since SVN revision numbers
+#     increase monotonically
+#   - lookups on SVN revision number are done via a binary search
+#   - Piping the file to xxd -c24 is a good way of dumping it for
+#     viewing or editing (piped back through xxd -r), should the need
+#     ever arise.
+#   - The last record can be padding revision with an all-zero sha1
+#     This is used to optimize fetch performance when using multiple
+#     "fetch" directives in .git/config
+#
+# These files are disposable unless noMetadata or useSvmProps is set
+
+sub _rev_map_set {
+	my ($fh, $rev, $commit) = @_;
+
+	binmode $fh or croak "binmode: $!";
+	my $size = (stat($fh))[7];
+	($size % 24) == 0 or croak "inconsistent size: $size";
+
+	my $wr_offset = 0;
+	if ($size > 0) {
+		sysseek($fh, -24, SEEK_END) or croak "seek: $!";
+		my $read = sysread($fh, my $buf, 24) or croak "read: $!";
+		$read == 24 or croak "read only $read bytes (!= 24)";
+		my ($last_rev, $last_commit) = unpack(rev_map_fmt, $buf);
+		if ($last_commit eq ('0' x40)) {
+			if ($size >= 48) {
+				sysseek($fh, -48, SEEK_END) or croak "seek: $!";
+				$read = sysread($fh, $buf, 24) or
+				    croak "read: $!";
+				$read == 24 or
+				    croak "read only $read bytes (!= 24)";
+				($last_rev, $last_commit) =
+				    unpack(rev_map_fmt, $buf);
+				if ($last_commit eq ('0' x40)) {
+					croak "inconsistent .rev_map\n";
+				}
+			}
+			if ($last_rev >= $rev) {
+				croak "last_rev is higher!: $last_rev >= $rev";
+			}
+			$wr_offset = -24;
+		}
+	}
+	sysseek($fh, $wr_offset, SEEK_END) or croak "seek: $!";
+	syswrite($fh, pack(rev_map_fmt, $rev, $commit), 24) == 24 or
+	  croak "write: $!";
+}
+
+sub _rev_map_reset {
+	my ($fh, $rev, $commit) = @_;
+	my $c = _rev_map_get($fh, $rev);
+	$c eq $commit or die "_rev_map_reset(@_) commit $c does not match!\n";
+	my $offset = sysseek($fh, 0, SEEK_CUR) or croak "seek: $!";
+	truncate $fh, $offset or croak "truncate: $!";
+}
+
+sub mkfile {
+	my ($path) = @_;
+	unless (-e $path) {
+		my ($dir, $base) = ($path =~ m#^(.*?)/?([^/]+)$#);
+		mkpath([$dir]) unless -d $dir;
+		open my $fh, '>>', $path or die "Couldn't create $path: $!\n";
+		close $fh or die "Couldn't close (create) $path: $!\n";
+	}
+}
+
+sub rev_map_set {
+	my ($self, $rev, $commit, $update_ref, $uuid) = @_;
+	defined $commit or die "missing arg3\n";
+	length $commit == 40 or die "arg3 must be a full SHA1 hexsum\n";
+	my $db = $self->map_path($uuid);
+	my $db_lock = "$db.lock";
+	my $sigmask;
+	$update_ref ||= 0;
+	if ($update_ref) {
+		$sigmask = POSIX::SigSet->new();
+		my $signew = POSIX::SigSet->new(SIGINT, SIGHUP, SIGTERM,
+			SIGALRM, SIGUSR1, SIGUSR2);
+		sigprocmask(SIG_BLOCK, $signew, $sigmask) or
+			croak "Can't block signals: $!";
+	}
+	mkfile($db);
+
+	$LOCKFILES{$db_lock} = 1;
+	my $sync;
+	# both of these options make our .rev_db file very, very important
+	# and we can't afford to lose it because rebuild() won't work
+	if ($self->use_svm_props || $self->no_metadata) {
+		require File::Copy;
+		$sync = 1;
+		File::Copy::copy($db, $db_lock) or die "rev_map_set(@_): ",
+					   "Failed to copy: ",
+					   "$db => $db_lock ($!)\n";
+	} else {
+		rename $db, $db_lock or die "rev_map_set(@_): ",
+					    "Failed to rename: ",
+					    "$db => $db_lock ($!)\n";
+	}
+
+	sysopen(my $fh, $db_lock, O_RDWR | O_CREAT)
+	     or croak "Couldn't open $db_lock: $!\n";
+	if ($update_ref eq 'reset') {
+		clear_memoized_mergeinfo_caches();
+		_rev_map_reset($fh, $rev, $commit);
+	} else {
+		_rev_map_set($fh, $rev, $commit);
+	}
+
+	if ($sync) {
+		$fh->flush or die "Couldn't flush $db_lock: $!\n";
+		$fh->sync or die "Couldn't sync $db_lock: $!\n";
+	}
+	close $fh or croak $!;
+	if ($update_ref) {
+		$_head = $self;
+		my $note = "";
+		$note = " ($update_ref)" if ($update_ref !~ /^\d*$/);
+		command_noisy('update-ref', '-m', "r$rev$note",
+		              $self->refname, $commit);
+	}
+	rename $db_lock, $db or die "rev_map_set(@_): ", "Failed to rename: ",
+	                            "$db_lock => $db ($!)\n";
+	delete $LOCKFILES{$db_lock};
+	if ($update_ref) {
+		sigprocmask(SIG_SETMASK, $sigmask) or
+			croak "Can't restore signal mask: $!";
+	}
+}
+
+# If want_commit, this will return an array of (rev, commit) where
+# commit _must_ be a valid commit in the archive.
+# Otherwise, it'll return the max revision (whether or not the
+# commit is valid or just a 0x40 placeholder).
+sub rev_map_max {
+	my ($self, $want_commit) = @_;
+	$self->rebuild;
+	my ($r, $c) = $self->rev_map_max_norebuild($want_commit);
+	$want_commit ? ($r, $c) : $r;
+}
+
+sub rev_map_max_norebuild {
+	my ($self, $want_commit) = @_;
+	my $map_path = $self->map_path;
+	stat $map_path or return $want_commit ? (0, undef) : 0;
+	sysopen(my $fh, $map_path, O_RDONLY) or croak "open: $!";
+	binmode $fh or croak "binmode: $!";
+	my $size = (stat($fh))[7];
+	($size % 24) == 0 or croak "inconsistent size: $size";
+
+	if ($size == 0) {
+		close $fh or croak "close: $!";
+		return $want_commit ? (0, undef) : 0;
+	}
+
+	sysseek($fh, -24, SEEK_END) or croak "seek: $!";
+	sysread($fh, my $buf, 24) == 24 or croak "read: $!";
+	my ($r, $c) = unpack(rev_map_fmt, $buf);
+	if ($want_commit && $c eq ('0' x40)) {
+		if ($size < 48) {
+			return $want_commit ? (0, undef) : 0;
+		}
+		sysseek($fh, -48, SEEK_END) or croak "seek: $!";
+		sysread($fh, $buf, 24) == 24 or croak "read: $!";
+		($r, $c) = unpack(rev_map_fmt, $buf);
+		if ($c eq ('0'x40)) {
+			croak "Penultimate record is all-zeroes in $map_path";
+		}
+	}
+	close $fh or croak "close: $!";
+	$want_commit ? ($r, $c) : $r;
+}
+
+sub rev_map_get {
+	my ($self, $rev, $uuid) = @_;
+	my $map_path = $self->map_path($uuid);
+	return undef unless -e $map_path;
+
+	sysopen(my $fh, $map_path, O_RDONLY) or croak "open: $!";
+	my $c = _rev_map_get($fh, $rev);
+	close($fh) or croak "close: $!";
+	$c
+}
+
+sub _rev_map_get {
+	my ($fh, $rev) = @_;
+
+	binmode $fh or croak "binmode: $!";
+	my $size = (stat($fh))[7];
+	($size % 24) == 0 or croak "inconsistent size: $size";
+
+	if ($size == 0) {
+		return undef;
+	}
+
+	my ($l, $u) = (0, $size - 24);
+	my ($r, $c, $buf);
+
+	while ($l <= $u) {
+		my $i = int(($l/24 + $u/24) / 2) * 24;
+		sysseek($fh, $i, SEEK_SET) or croak "seek: $!";
+		sysread($fh, my $buf, 24) == 24 or croak "read: $!";
+		my ($r, $c) = unpack(rev_map_fmt, $buf);
+
+		if ($r < $rev) {
+			$l = $i + 24;
+		} elsif ($r > $rev) {
+			$u = $i - 24;
+		} else { # $r == $rev
+			return $c eq ('0' x 40) ? undef : $c;
+		}
+	}
+	undef;
+}
+
+# Finds the first svn revision that exists on (if $eq_ok is true) or
+# before $rev for the current branch.  It will not search any lower
+# than $min_rev.  Returns the git commit hash and svn revision number
+# if found, else (undef, undef).
+sub find_rev_before {
+	my ($self, $rev, $eq_ok, $min_rev) = @_;
+	--$rev unless $eq_ok;
+	$min_rev ||= 1;
+	my $max_rev = $self->rev_map_max;
+	$rev = $max_rev if ($rev > $max_rev);
+	while ($rev >= $min_rev) {
+		if (my $c = $self->rev_map_get($rev)) {
+			return ($rev, $c);
+		}
+		--$rev;
+	}
+	return (undef, undef);
+}
+
+# Finds the first svn revision that exists on (if $eq_ok is true) or
+# after $rev for the current branch.  It will not search any higher
+# than $max_rev.  Returns the git commit hash and svn revision number
+# if found, else (undef, undef).
+sub find_rev_after {
+	my ($self, $rev, $eq_ok, $max_rev) = @_;
+	++$rev unless $eq_ok;
+	$max_rev ||= $self->rev_map_max;
+	while ($rev <= $max_rev) {
+		if (my $c = $self->rev_map_get($rev)) {
+			return ($rev, $c);
+		}
+		++$rev;
+	}
+	return (undef, undef);
+}
+
+sub _new {
+	my ($class, $repo_id, $ref_id, $path) = @_;
+	unless (defined $repo_id && length $repo_id) {
+		$repo_id = $default_repo_id;
+	}
+	unless (defined $ref_id && length $ref_id) {
+		# Access the prefix option from the git-svn main program if it's loaded.
+		my $prefix = defined &::opt_prefix ? ::opt_prefix() : "";
+		$_[2] = $ref_id =
+		             "refs/remotes/$prefix$default_ref_id";
+	}
+	$_[1] = $repo_id;
+	my $svn_dir = svn_dir();
+	my $dir = "$svn_dir/$ref_id";
+
+	# Older repos imported by us used $svn_dir/foo instead of
+	# $svn_dir/refs/remotes/foo when tracking refs/remotes/foo
+	if ($ref_id =~ m{^refs/remotes/(.+)}) {
+		my $old_dir = "$svn_dir/$1";
+		if (-d $old_dir && ! -d $dir) {
+			$dir = $old_dir;
+		}
+	}
+
+	$_[3] = $path = '' unless (defined $path);
+	mkpath([$dir]);
+	my $obj = bless {
+		ref_id => $ref_id, dir => $dir, index => "$dir/index",
+	        config => "$svn_dir/config",
+	        map_root => "$dir/.rev_map", repo_id => $repo_id }, $class;
+
+	# Ensure it gets canonicalized
+	$obj->path($path);
+
+	return $obj;
+}
+
+sub path {
+	my $self = shift;
+
+	if (@_) {
+		my $path = shift;
+		$self->{_path} = canonicalize_path($path);
+		return;
+	}
+
+	return $self->{_path};
+}
+
+sub url {
+	my $self = shift;
+
+	if (@_) {
+		my $url = shift;
+		$self->{url} = canonicalize_url($url);
+		return;
+	}
+
+	return $self->{url};
+}
+
+# for read-only access of old .rev_db formats
+sub unlink_rev_db_symlink {
+	my ($self) = @_;
+	my $link = $self->rev_db_path;
+	$link =~ s/\.[\w-]+$// or croak "missing UUID at the end of $link";
+	if (-l $link) {
+		unlink $link or croak "unlink: $link failed!";
+	}
+}
+
+sub rev_db_path {
+	my ($self, $uuid) = @_;
+	my $db_path = $self->map_path($uuid);
+	$db_path =~ s{/\.rev_map\.}{/\.rev_db\.}
+	    or croak "map_path: $db_path does not contain '/.rev_map.' !";
+	$db_path;
+}
+
+# the new replacement for .rev_db
+sub map_path {
+	my ($self, $uuid) = @_;
+	$uuid ||= $self->ra_uuid;
+	"$self->{map_root}.$uuid";
+}
+
+sub uri_encode {
+	my ($f) = @_;
+	$f =~ s#([^a-zA-Z0-9\*!\:_\./\-])#sprintf("%%%02X",ord($1))#eg;
+	$f
+}
+
+sub uri_decode {
+	my ($f) = @_;
+	$f =~ s#%([0-9a-fA-F]{2})#chr(hex($1))#eg;
+	$f
+}
+
+sub remove_username {
+	$_[0] =~ s{^([^:]*://)[^@]+@}{$1};
+}
+
+1;
diff --git a/third_party/git/perl/Git/SVN/Editor.pm b/third_party/git/perl/Git/SVN/Editor.pm
new file mode 100644
index 000000000000..0df16ed72688
--- /dev/null
+++ b/third_party/git/perl/Git/SVN/Editor.pm
@@ -0,0 +1,605 @@
+package Git::SVN::Editor;
+use vars qw/@ISA $_rmdir $_cp_similarity $_find_copies_harder $_rename_limit/;
+use strict;
+use warnings;
+use SVN::Core;
+use SVN::Delta;
+use Carp qw/croak/;
+use Git qw/command command_oneline command_noisy command_output_pipe
+           command_input_pipe command_close_pipe
+           command_bidi_pipe command_close_bidi_pipe
+           get_record/;
+
+BEGIN {
+	@ISA = qw(SVN::Delta::Editor);
+}
+
+sub new {
+	my ($class, $opts) = @_;
+	foreach (qw/svn_path r ra tree_a tree_b log editor_cb/) {
+		die "$_ required!\n" unless (defined $opts->{$_});
+	}
+
+	my $pool = SVN::Pool->new;
+	my $mods = generate_diff($opts->{tree_a}, $opts->{tree_b});
+	my $types = check_diff_paths($opts->{ra}, $opts->{svn_path},
+	                             $opts->{r}, $mods);
+
+	# $opts->{ra} functions should not be used after this:
+	my @ce  = $opts->{ra}->get_commit_editor($opts->{log},
+	                                        $opts->{editor_cb}, $pool);
+	my $self = SVN::Delta::Editor->new(@ce, $pool);
+	bless $self, $class;
+	foreach (qw/svn_path r tree_a tree_b/) {
+		$self->{$_} = $opts->{$_};
+	}
+	$self->{url} = $opts->{ra}->{url};
+	$self->{mods} = $mods;
+	$self->{types} = $types;
+	$self->{pool} = $pool;
+	$self->{bat} = { '' => $self->open_root($self->{r}, $self->{pool}) };
+	$self->{rm} = { };
+	$self->{path_prefix} = length $self->{svn_path} ?
+	                       "$self->{svn_path}/" : '';
+	$self->{config} = $opts->{config};
+	$self->{mergeinfo} = $opts->{mergeinfo};
+	$self->{pathnameencoding} = Git::config('svn.pathnameencoding');
+	return $self;
+}
+
+sub generate_diff {
+	my ($tree_a, $tree_b) = @_;
+	my @diff_tree = qw(diff-tree -z -r);
+	if ($_cp_similarity) {
+		push @diff_tree, "-C$_cp_similarity";
+	} else {
+		push @diff_tree, '-C';
+	}
+	push @diff_tree, '--find-copies-harder' if $_find_copies_harder;
+	push @diff_tree, "-l$_rename_limit" if defined $_rename_limit;
+	push @diff_tree, $tree_a, $tree_b;
+	my ($diff_fh, $ctx) = command_output_pipe(@diff_tree);
+	my $state = 'meta';
+	my @mods;
+	while (defined($_ = get_record($diff_fh, "\0"))) {
+		if ($state eq 'meta' && /^:(\d{6})\s(\d{6})\s
+					($::sha1)\s($::sha1)\s
+					([MTCRAD])\d*$/xo) {
+			push @mods, {	mode_a => $1, mode_b => $2,
+					sha1_a => $3, sha1_b => $4,
+					chg => $5 };
+			if ($5 =~ /^(?:C|R)$/) {
+				$state = 'file_a';
+			} else {
+				$state = 'file_b';
+			}
+		} elsif ($state eq 'file_a') {
+			my $x = $mods[$#mods] or croak "Empty array\n";
+			if ($x->{chg} !~ /^(?:C|R)$/) {
+				croak "Error parsing $_, $x->{chg}\n";
+			}
+			$x->{file_a} = $_;
+			$state = 'file_b';
+		} elsif ($state eq 'file_b') {
+			my $x = $mods[$#mods] or croak "Empty array\n";
+			if (exists $x->{file_a} && $x->{chg} !~ /^(?:C|R)$/) {
+				croak "Error parsing $_, $x->{chg}\n";
+			}
+			if (!exists $x->{file_a} && $x->{chg} =~ /^(?:C|R)$/) {
+				croak "Error parsing $_, $x->{chg}\n";
+			}
+			$x->{file_b} = $_;
+			$state = 'meta';
+		} else {
+			croak "Error parsing $_\n";
+		}
+	}
+	command_close_pipe($diff_fh, $ctx);
+	\@mods;
+}
+
+sub check_diff_paths {
+	my ($ra, $pfx, $rev, $mods) = @_;
+	my %types;
+	$pfx .= '/' if length $pfx;
+
+	sub type_diff_paths {
+		my ($ra, $types, $path, $rev) = @_;
+		my @p = split m#/+#, $path;
+		my $c = shift @p;
+		unless (defined $types->{$c}) {
+			$types->{$c} = $ra->check_path($c, $rev);
+		}
+		while (@p) {
+			$c .= '/' . shift @p;
+			next if defined $types->{$c};
+			$types->{$c} = $ra->check_path($c, $rev);
+		}
+	}
+
+	foreach my $m (@$mods) {
+		foreach my $f (qw/file_a file_b/) {
+			next unless defined $m->{$f};
+			my ($dir) = ($m->{$f} =~ m#^(.*?)/?(?:[^/]+)$#);
+			if (length $pfx.$dir && ! defined $types{$dir}) {
+				type_diff_paths($ra, \%types, $pfx.$dir, $rev);
+			}
+		}
+	}
+	\%types;
+}
+
+sub split_path {
+	return ($_[0] =~ m#^(.*?)/?([^/]+)$#);
+}
+
+sub repo_path {
+	my ($self, $path) = @_;
+	if (my $enc = $self->{pathnameencoding}) {
+		require Encode;
+		Encode::from_to($path, $enc, 'UTF-8');
+	}
+	$self->{path_prefix}.(defined $path ? $path : '');
+}
+
+sub url_path {
+	my ($self, $path) = @_;
+	$path = $self->repo_path($path);
+	if ($self->{url} =~ m#^https?://#) {
+		# characters are taken from subversion/libsvn_subr/path.c
+		$path =~ s#([^~a-zA-Z0-9_./!$&'()*+,-])#sprintf("%%%02X",ord($1))#eg;
+	}
+	$self->{url} . '/' . $path;
+}
+
+sub rmdirs {
+	my ($self) = @_;
+	my $rm = $self->{rm};
+	delete $rm->{''}; # we never delete the url we're tracking
+	return unless %$rm;
+
+	foreach (keys %$rm) {
+		my @d = split m#/#, $_;
+		my $c = shift @d;
+		$rm->{$c} = 1;
+		while (@d) {
+			$c .= '/' . shift @d;
+			$rm->{$c} = 1;
+		}
+	}
+	delete $rm->{$self->{svn_path}};
+	delete $rm->{''}; # we never delete the url we're tracking
+	return unless %$rm;
+
+	my ($fh, $ctx) = command_output_pipe(qw/ls-tree --name-only -r -z/,
+	                                     $self->{tree_b});
+	while (defined($_ = get_record($fh, "\0"))) {
+		my @dn = split m#/#, $_;
+		while (pop @dn) {
+			delete $rm->{join '/', @dn};
+		}
+		unless (%$rm) {
+			close $fh;
+			return;
+		}
+	}
+	command_close_pipe($fh, $ctx);
+
+	my ($r, $p, $bat) = ($self->{r}, $self->{pool}, $self->{bat});
+	foreach my $d (sort { $b =~ tr#/#/# <=> $a =~ tr#/#/# } keys %$rm) {
+		$self->close_directory($bat->{$d}, $p);
+		my ($dn) = ($d =~ m#^(.*?)/?(?:[^/]+)$#);
+		print "\tD+\t$d/\n" unless $::_q;
+		$self->SUPER::delete_entry($d, $r, $bat->{$dn}, $p);
+		delete $bat->{$d};
+	}
+}
+
+sub open_or_add_dir {
+	my ($self, $full_path, $baton, $deletions) = @_;
+	my $t = $self->{types}->{$full_path};
+	if (!defined $t) {
+		die "$full_path not known in r$self->{r} or we have a bug!\n";
+	}
+	{
+		no warnings 'once';
+		# SVN::Node::none and SVN::Node::file are used only once,
+		# so we're shutting up Perl's warnings about them.
+		if ($t == $SVN::Node::none || defined($deletions->{$full_path})) {
+			return $self->add_directory($full_path, $baton,
+			    undef, -1, $self->{pool});
+		} elsif ($t == $SVN::Node::dir) {
+			return $self->open_directory($full_path, $baton,
+			    $self->{r}, $self->{pool});
+		} # no warnings 'once'
+		print STDERR "$full_path already exists in repository at ",
+		    "r$self->{r} and it is not a directory (",
+		    ($t == $SVN::Node::file ? 'file' : 'unknown'),"/$t)\n";
+	} # no warnings 'once'
+	exit 1;
+}
+
+sub ensure_path {
+	my ($self, $path, $deletions) = @_;
+	my $bat = $self->{bat};
+	my $repo_path = $self->repo_path($path);
+	return $bat->{''} unless (length $repo_path);
+
+	my @p = split m#/+#, $repo_path;
+	my $c = shift @p;
+	$bat->{$c} ||= $self->open_or_add_dir($c, $bat->{''}, $deletions);
+	while (@p) {
+		my $c0 = $c;
+		$c .= '/' . shift @p;
+		$bat->{$c} ||= $self->open_or_add_dir($c, $bat->{$c0}, $deletions);
+	}
+	return $bat->{$c};
+}
+
+# Subroutine to convert a globbing pattern to a regular expression.
+# From perl cookbook.
+sub glob2pat {
+	my $globstr = shift;
+	my %patmap = ('*' => '.*', '?' => '.', '[' => '[', ']' => ']');
+	$globstr =~ s{(.)} { $patmap{$1} || "\Q$1" }ge;
+	return '^' . $globstr . '$';
+}
+
+sub check_autoprop {
+	my ($self, $pattern, $properties, $file, $fbat) = @_;
+	# Convert the globbing pattern to a regular expression.
+	my $regex = glob2pat($pattern);
+	# Check if the pattern matches the file name.
+	if($file =~ m/($regex)/) {
+		# Parse the list of properties to set.
+		my @props = split(/;/, $properties);
+		foreach my $prop (@props) {
+			# Parse 'name=value' syntax and set the property.
+			if ($prop =~ /([^=]+)=(.*)/) {
+				my ($n,$v) = ($1,$2);
+				for ($n, $v) {
+					s/^\s+//; s/\s+$//;
+				}
+				$self->change_file_prop($fbat, $n, $v);
+			}
+		}
+	}
+}
+
+sub apply_autoprops {
+	my ($self, $file, $fbat) = @_;
+	my $conf_t = ${$self->{config}}{'config'};
+	no warnings 'once';
+	# Check [miscellany]/enable-auto-props in svn configuration.
+	if (SVN::_Core::svn_config_get_bool(
+		$conf_t,
+		$SVN::_Core::SVN_CONFIG_SECTION_MISCELLANY,
+		$SVN::_Core::SVN_CONFIG_OPTION_ENABLE_AUTO_PROPS,
+		0)) {
+		# Auto-props are enabled.  Enumerate them to look for matches.
+		my $callback = sub {
+			$self->check_autoprop($_[0], $_[1], $file, $fbat);
+		};
+		SVN::_Core::svn_config_enumerate(
+			$conf_t,
+			$SVN::_Core::SVN_CONFIG_SECTION_AUTO_PROPS,
+			$callback);
+	}
+}
+
+sub check_attr {
+	my ($attr,$path) = @_;
+	my $val = command_oneline("check-attr", $attr, "--", $path);
+	if ($val) { $val =~ s/^[^:]*:\s*[^:]*:\s*(.*)\s*$/$1/; }
+	return $val;
+}
+
+sub apply_manualprops {
+	my ($self, $file, $fbat) = @_;
+	my $pending_properties = check_attr( "svn-properties", $file );
+	if ($pending_properties eq "") { return; }
+	# Parse the list of properties to set.
+	my @props = split(/;/, $pending_properties);
+	# TODO: get existing properties to compare to
+	# - this fails for add so currently not done
+	# my $existing_props = ::get_svnprops($file);
+	my $existing_props = {};
+	# TODO: caching svn properties or storing them in .gitattributes
+	# would make that faster
+	foreach my $prop (@props) {
+		# Parse 'name=value' syntax and set the property.
+		if ($prop =~ /([^=]+)=(.*)/) {
+			my ($n,$v) = ($1,$2);
+			for ($n, $v) {
+				s/^\s+//; s/\s+$//;
+			}
+			my $existing = $existing_props->{$n};
+			if (!defined($existing) || $existing ne $v) {
+			    $self->change_file_prop($fbat, $n, $v);
+			}
+		}
+	}
+}
+
+sub A {
+	my ($self, $m, $deletions) = @_;
+	my ($dir, $file) = split_path($m->{file_b});
+	my $pbat = $self->ensure_path($dir, $deletions);
+	my $fbat = $self->add_file($self->repo_path($m->{file_b}), $pbat,
+					undef, -1);
+	print "\tA\t$m->{file_b}\n" unless $::_q;
+	$self->apply_autoprops($file, $fbat);
+	$self->apply_manualprops($m->{file_b}, $fbat);
+	$self->chg_file($fbat, $m);
+	$self->close_file($fbat,undef,$self->{pool});
+}
+
+sub C {
+	my ($self, $m, $deletions) = @_;
+	my ($dir, $file) = split_path($m->{file_b});
+	my $pbat = $self->ensure_path($dir, $deletions);
+	# workaround for a bug in svn serf backend (v1.8.5 and below):
+	# store third argument to ->add_file() in a local variable, to make it
+	# have the same lifetime as $fbat
+	my $upa = $self->url_path($m->{file_a});
+	my $fbat = $self->add_file($self->repo_path($m->{file_b}), $pbat,
+				$upa, $self->{r});
+	print "\tC\t$m->{file_a} => $m->{file_b}\n" unless $::_q;
+	$self->apply_manualprops($m->{file_b}, $fbat);
+	$self->chg_file($fbat, $m);
+	$self->close_file($fbat,undef,$self->{pool});
+}
+
+sub delete_entry {
+	my ($self, $path, $pbat) = @_;
+	my $rpath = $self->repo_path($path);
+	my ($dir, $file) = split_path($rpath);
+	$self->{rm}->{$dir} = 1;
+	$self->SUPER::delete_entry($rpath, $self->{r}, $pbat, $self->{pool});
+}
+
+sub R {
+	my ($self, $m, $deletions) = @_;
+	my ($dir, $file) = split_path($m->{file_b});
+	my $pbat = $self->ensure_path($dir, $deletions);
+	# workaround for a bug in svn serf backend, see comment in C() above
+	my $upa = $self->url_path($m->{file_a});
+	my $fbat = $self->add_file($self->repo_path($m->{file_b}), $pbat,
+				$upa, $self->{r});
+	print "\tR\t$m->{file_a} => $m->{file_b}\n" unless $::_q;
+	$self->apply_autoprops($file, $fbat);
+	$self->apply_manualprops($m->{file_b}, $fbat);
+	$self->chg_file($fbat, $m);
+	$self->close_file($fbat,undef,$self->{pool});
+
+	($dir, $file) = split_path($m->{file_a});
+	$pbat = $self->ensure_path($dir, $deletions);
+	$self->delete_entry($m->{file_a}, $pbat);
+}
+
+sub M {
+	my ($self, $m, $deletions) = @_;
+	my ($dir, $file) = split_path($m->{file_b});
+	my $pbat = $self->ensure_path($dir, $deletions);
+	my $fbat = $self->open_file($self->repo_path($m->{file_b}),
+				$pbat,$self->{r},$self->{pool});
+	print "\t$m->{chg}\t$m->{file_b}\n" unless $::_q;
+	$self->apply_manualprops($m->{file_b}, $fbat);
+	$self->chg_file($fbat, $m);
+	$self->close_file($fbat,undef,$self->{pool});
+}
+
+sub T {
+	my ($self, $m, $deletions) = @_;
+
+	# Work around subversion issue 4091: toggling the "is a
+	# symlink" property requires removing and re-adding a
+	# file or else "svn up" on affected clients trips an
+	# assertion and aborts.
+	if (($m->{mode_b} =~ /^120/ && $m->{mode_a} !~ /^120/) ||
+	    ($m->{mode_b} !~ /^120/ && $m->{mode_a} =~ /^120/)) {
+		$self->D({
+			mode_a => $m->{mode_a}, mode_b => '000000',
+			sha1_a => $m->{sha1_a}, sha1_b => '0' x 40,
+			chg => 'D', file_b => $m->{file_b}
+		}, $deletions);
+		$self->A({
+			mode_a => '000000', mode_b => $m->{mode_b},
+			sha1_a => '0' x 40, sha1_b => $m->{sha1_b},
+			chg => 'A', file_b => $m->{file_b}
+		}, $deletions);
+		return;
+	}
+
+	$self->M($m, $deletions);
+}
+
+sub change_file_prop {
+	my ($self, $fbat, $pname, $pval) = @_;
+	$self->SUPER::change_file_prop($fbat, $pname, $pval, $self->{pool});
+}
+
+sub change_dir_prop {
+	my ($self, $pbat, $pname, $pval) = @_;
+	$self->SUPER::change_dir_prop($pbat, $pname, $pval, $self->{pool});
+}
+
+sub _chg_file_get_blob ($$$$) {
+	my ($self, $fbat, $m, $which) = @_;
+	my $fh = $::_repository->temp_acquire("git_blob_$which");
+	if ($m->{"mode_$which"} =~ /^120/) {
+		print $fh 'link ' or croak $!;
+		$self->change_file_prop($fbat,'svn:special','*');
+	} elsif ($m->{mode_a} =~ /^120/ && $m->{"mode_$which"} !~ /^120/) {
+		$self->change_file_prop($fbat,'svn:special',undef);
+	}
+	my $blob = $m->{"sha1_$which"};
+	return ($fh,) if ($blob =~ /^0{40}$/);
+	my $size = $::_repository->cat_blob($blob, $fh);
+	croak "Failed to read object $blob" if ($size < 0);
+	$fh->flush == 0 or croak $!;
+	seek $fh, 0, 0 or croak $!;
+
+	my $exp = ::md5sum($fh);
+	seek $fh, 0, 0 or croak $!;
+	return ($fh, $exp);
+}
+
+sub chg_file {
+	my ($self, $fbat, $m) = @_;
+	if ($m->{mode_b} =~ /755$/ && $m->{mode_a} !~ /755$/) {
+		$self->change_file_prop($fbat,'svn:executable','*');
+	} elsif ($m->{mode_b} !~ /755$/ && $m->{mode_a} =~ /755$/) {
+		$self->change_file_prop($fbat,'svn:executable',undef);
+	}
+	my ($fh_a, $exp_a) = _chg_file_get_blob $self, $fbat, $m, 'a';
+	my ($fh_b, $exp_b) = _chg_file_get_blob $self, $fbat, $m, 'b';
+	my $pool = SVN::Pool->new;
+	my $atd = $self->apply_textdelta($fbat, $exp_a, $pool);
+	if (-s $fh_a) {
+		my $txstream = SVN::TxDelta::new ($fh_a, $fh_b, $pool);
+		my $res = SVN::TxDelta::send_txstream($txstream, @$atd, $pool);
+		if (defined $res) {
+			die "Unexpected result from send_txstream: $res\n",
+			    "(SVN::Core::VERSION: $SVN::Core::VERSION)\n";
+		}
+	} else {
+		my $got = SVN::TxDelta::send_stream($fh_b, @$atd, $pool);
+		die "Checksum mismatch\nexpected: $exp_b\ngot: $got\n"
+		    if ($got ne $exp_b);
+	}
+	Git::temp_release($fh_b, 1);
+	Git::temp_release($fh_a, 1);
+	$pool->clear;
+}
+
+sub D {
+	my ($self, $m, $deletions) = @_;
+	my ($dir, $file) = split_path($m->{file_b});
+	my $pbat = $self->ensure_path($dir, $deletions);
+	print "\tD\t$m->{file_b}\n" unless $::_q;
+	$self->delete_entry($m->{file_b}, $pbat);
+}
+
+sub close_edit {
+	my ($self) = @_;
+	my ($p,$bat) = ($self->{pool}, $self->{bat});
+	foreach (sort { $b =~ tr#/#/# <=> $a =~ tr#/#/# } keys %$bat) {
+		next if $_ eq '';
+		$self->close_directory($bat->{$_}, $p);
+	}
+	$self->close_directory($bat->{''}, $p);
+	$self->SUPER::close_edit($p);
+	$p->clear;
+}
+
+sub abort_edit {
+	my ($self) = @_;
+	$self->SUPER::abort_edit($self->{pool});
+}
+
+sub DESTROY {
+	my $self = shift;
+	$self->SUPER::DESTROY(@_);
+	$self->{pool}->clear;
+}
+
+# this drives the editor
+sub apply_diff {
+	my ($self) = @_;
+	my $mods = $self->{mods};
+	my %o = ( D => 0, C => 1, R => 2, A => 3, M => 4, T => 5 );
+	my %deletions;
+
+	foreach my $m (@$mods) {
+		if ($m->{chg} eq "D") {
+			$deletions{$m->{file_b}} = 1;
+		}
+	}
+
+	foreach my $m (sort { $o{$a->{chg}} <=> $o{$b->{chg}} } @$mods) {
+		my $f = $m->{chg};
+		if (defined $o{$f}) {
+			$self->$f($m, \%deletions);
+		} else {
+			fatal("Invalid change type: $f");
+		}
+	}
+
+	if (defined($self->{mergeinfo})) {
+		$self->change_dir_prop($self->{bat}{''}, "svn:mergeinfo",
+			               $self->{mergeinfo});
+	}
+	$self->rmdirs if $_rmdir;
+	if (@$mods == 0 && !defined($self->{mergeinfo})) {
+		$self->abort_edit;
+	} else {
+		$self->close_edit;
+	}
+	return scalar @$mods;
+}
+
+1;
+__END__
+
+=head1 NAME
+
+Git::SVN::Editor - commit driver for "git svn set-tree" and dcommit
+
+=head1 SYNOPSIS
+
+	use Git::SVN::Editor;
+	use Git::SVN::Ra;
+
+	my $ra = Git::SVN::Ra->new($url);
+	my %opts = (
+		r => 19,
+		log => "log message",
+		ra => $ra,
+		config => SVN::Core::config_get_config($svn_config_dir),
+		tree_a => "$commit^",
+		tree_b => "$commit",
+		editor_cb => sub { print "Committed r$_[0]\n"; },
+		mergeinfo => "/branches/foo:1-10",
+		svn_path => "trunk"
+	);
+	Git::SVN::Editor->new(\%opts)->apply_diff or print "No changes\n";
+
+	my $re = Git::SVN::Editor::glob2pat("trunk/*");
+	if ($branchname =~ /$re/) {
+		print "matched!\n";
+	}
+
+=head1 DESCRIPTION
+
+This module is an implementation detail of the "git svn" command.
+Do not use it unless you are developing git-svn.
+
+This module adapts the C<SVN::Delta::Editor> object returned by
+C<SVN::Delta::get_commit_editor> and drives it to convey the
+difference between two git tree objects to a remote Subversion
+repository.
+
+The interface will change as git-svn evolves.
+
+=head1 DEPENDENCIES
+
+Subversion perl bindings,
+the core L<Carp> module,
+and git's L<Git> helper module.
+
+C<Git::SVN::Editor> has not been tested using callers other than
+B<git-svn> itself.
+
+=head1 SEE ALSO
+
+L<SVN::Delta>,
+L<Git::SVN::Fetcher>.
+
+=head1 INCOMPATIBILITIES
+
+None reported.
+
+=head1 BUGS
+
+None.
diff --git a/third_party/git/perl/Git/SVN/Fetcher.pm b/third_party/git/perl/Git/SVN/Fetcher.pm
new file mode 100644
index 000000000000..64e900a0e910
--- /dev/null
+++ b/third_party/git/perl/Git/SVN/Fetcher.pm
@@ -0,0 +1,622 @@
+package Git::SVN::Fetcher;
+use vars qw/@ISA $_ignore_regex $_include_regex $_preserve_empty_dirs
+            $_placeholder_filename @deleted_gpath %added_placeholder
+            $repo_id/;
+use strict;
+use warnings;
+use SVN::Delta;
+use Carp qw/croak/;
+use File::Basename qw/dirname/;
+use Git qw/command command_oneline command_noisy command_output_pipe
+           command_input_pipe command_close_pipe
+           command_bidi_pipe command_close_bidi_pipe
+           get_record/;
+BEGIN {
+	@ISA = qw(SVN::Delta::Editor);
+}
+
+# file baton members: path, mode_a, mode_b, pool, fh, blob, base
+sub new {
+	my ($class, $git_svn, $switch_path) = @_;
+	my $self = SVN::Delta::Editor->new;
+	bless $self, $class;
+	if (exists $git_svn->{last_commit}) {
+		$self->{c} = $git_svn->{last_commit};
+		$self->{empty_symlinks} =
+		                  _mark_empty_symlinks($git_svn, $switch_path);
+	}
+
+	# some options are read globally, but can be overridden locally
+	# per [svn-remote "..."] section.  Command-line options will *NOT*
+	# override options set in an [svn-remote "..."] section
+	$repo_id = $git_svn->{repo_id};
+	my $k = "svn-remote.$repo_id.ignore-paths";
+	my $v = eval { command_oneline('config', '--get', $k) };
+	$self->{ignore_regex} = $v;
+
+	$k = "svn-remote.$repo_id.include-paths";
+	$v = eval { command_oneline('config', '--get', $k) };
+	$self->{include_regex} = $v;
+
+	$k = "svn-remote.$repo_id.preserve-empty-dirs";
+	$v = eval { command_oneline('config', '--get', '--bool', $k) };
+	if ($v && $v eq 'true') {
+		$_preserve_empty_dirs = 1;
+		$k = "svn-remote.$repo_id.placeholder-filename";
+		$v = eval { command_oneline('config', '--get', $k) };
+		$_placeholder_filename = $v;
+	}
+
+	# Load the list of placeholder files added during previous invocations.
+	$k = "svn-remote.$repo_id.added-placeholder";
+	$v = eval { command_oneline('config', '--get-all', $k) };
+	if ($_preserve_empty_dirs && $v) {
+		# command() prints errors to stderr, so we only call it if
+		# command_oneline() succeeded.
+		my @v = command('config', '--get-all', $k);
+		$added_placeholder{ dirname($_) } = $_ foreach @v;
+	}
+
+	$self->{empty} = {};
+	$self->{dir_prop} = {};
+	$self->{file_prop} = {};
+	$self->{absent_dir} = {};
+	$self->{absent_file} = {};
+	require Git::IndexInfo;
+	$self->{gii} = $git_svn->tmp_index_do(sub { Git::IndexInfo->new });
+	$self->{pathnameencoding} = Git::config('svn.pathnameencoding');
+	$self;
+}
+
+# this uses the Ra object, so it must be called before do_{switch,update},
+# not inside them (when the Git::SVN::Fetcher object is passed) to
+# do_{switch,update}
+sub _mark_empty_symlinks {
+	my ($git_svn, $switch_path) = @_;
+	my $bool = Git::config_bool('svn.brokenSymlinkWorkaround');
+	return {} if (!defined($bool)) || (defined($bool) && ! $bool);
+
+	my %ret;
+	my ($rev, $cmt) = $git_svn->last_rev_commit;
+	return {} unless ($rev && $cmt);
+
+	# allow the warning to be printed for each revision we fetch to
+	# ensure the user sees it.  The user can also disable the workaround
+	# on the repository even while git svn is running and the next
+	# revision fetched will skip this expensive function.
+	my $printed_warning;
+	chomp(my $empty_blob = `git hash-object -t blob --stdin < /dev/null`);
+	my ($ls, $ctx) = command_output_pipe(qw/ls-tree -r -z/, $cmt);
+	my $pfx = defined($switch_path) ? $switch_path : $git_svn->path;
+	$pfx .= '/' if length($pfx);
+	while (defined($_ = get_record($ls, "\0"))) {
+		s/\A100644 blob $empty_blob\t//o or next;
+		unless ($printed_warning) {
+			print STDERR "Scanning for empty symlinks, ",
+			             "this may take a while if you have ",
+				     "many empty files\n",
+				     "You may disable this with `",
+				     "git config svn.brokenSymlinkWorkaround ",
+				     "false'.\n",
+				     "This may be done in a different ",
+				     "terminal without restarting ",
+				     "git svn\n";
+			$printed_warning = 1;
+		}
+		my $path = $_;
+		my (undef, $props) =
+		               $git_svn->ra->get_file($pfx.$path, $rev, undef);
+		if ($props->{'svn:special'}) {
+			$ret{$path} = 1;
+		}
+	}
+	command_close_pipe($ls, $ctx);
+	\%ret;
+}
+
+# returns true if a given path is inside a ".git" directory
+sub in_dot_git {
+	$_[0] =~ m{(?:^|/)\.git(?:/|$)};
+}
+
+# return value: 0 -- don't ignore, 1 -- ignore
+# This will also check whether the path is explicitly included
+sub is_path_ignored {
+	my ($self, $path) = @_;
+	return 1 if in_dot_git($path);
+	return 1 if defined($self->{ignore_regex}) &&
+	            $path =~ m!$self->{ignore_regex}!;
+	return 0 if defined($self->{include_regex}) &&
+	            $path =~ m!$self->{include_regex}!;
+	return 0 if defined($_include_regex) &&
+	            $path =~ m!$_include_regex!;
+	return 1 if defined($self->{include_regex});
+	return 1 if defined($_include_regex);
+	return 0 unless defined($_ignore_regex);
+	return 1 if $path =~ m!$_ignore_regex!o;
+	return 0;
+}
+
+sub set_path_strip {
+	my ($self, $path) = @_;
+	$self->{path_strip} = qr/^\Q$path\E(\/|$)/ if length $path;
+}
+
+sub open_root {
+	{ path => '' };
+}
+
+sub open_directory {
+	my ($self, $path, $pb, $rev) = @_;
+	{ path => $path };
+}
+
+sub git_path {
+	my ($self, $path) = @_;
+	if (my $enc = $self->{pathnameencoding}) {
+		require Encode;
+		Encode::from_to($path, 'UTF-8', $enc);
+	}
+	if ($self->{path_strip}) {
+		$path =~ s!$self->{path_strip}!! or
+		  die "Failed to strip path '$path' ($self->{path_strip})\n";
+	}
+	$path;
+}
+
+sub delete_entry {
+	my ($self, $path, $rev, $pb) = @_;
+	return undef if $self->is_path_ignored($path);
+
+	my $gpath = $self->git_path($path);
+	return undef if ($gpath eq '');
+
+	# remove entire directories.
+	my ($tree) = (command('ls-tree', '-z', $self->{c}, "./$gpath")
+	                 =~ /\A040000 tree ([a-f\d]{40})\t\Q$gpath\E\0/);
+	if ($tree) {
+		my ($ls, $ctx) = command_output_pipe(qw/ls-tree
+		                                     -r --name-only -z/,
+				                     $tree);
+		while (defined($_ = get_record($ls, "\0"))) {
+			my $rmpath = "$gpath/$_";
+			$self->{gii}->remove($rmpath);
+			print "\tD\t$rmpath\n" unless $::_q;
+		}
+		print "\tD\t$gpath/\n" unless $::_q;
+		command_close_pipe($ls, $ctx);
+	} else {
+		$self->{gii}->remove($gpath);
+		print "\tD\t$gpath\n" unless $::_q;
+	}
+	# Don't add to @deleted_gpath if we're deleting a placeholder file.
+	push @deleted_gpath, $gpath unless $added_placeholder{dirname($path)};
+	$self->{empty}->{$path} = 0;
+	undef;
+}
+
+sub open_file {
+	my ($self, $path, $pb, $rev) = @_;
+	my ($mode, $blob);
+
+	goto out if $self->is_path_ignored($path);
+
+	my $gpath = $self->git_path($path);
+	($mode, $blob) = (command('ls-tree', '-z', $self->{c}, "./$gpath")
+	                     =~ /\A(\d{6}) blob ([a-f\d]{40})\t\Q$gpath\E\0/);
+	unless (defined $mode && defined $blob) {
+		die "$path was not found in commit $self->{c} (r$rev)\n";
+	}
+	if ($mode eq '100644' && $self->{empty_symlinks}->{$path}) {
+		$mode = '120000';
+	}
+out:
+	{ path => $path, mode_a => $mode, mode_b => $mode, blob => $blob,
+	  pool => SVN::Pool->new, action => 'M' };
+}
+
+sub add_file {
+	my ($self, $path, $pb, $cp_path, $cp_rev) = @_;
+	my $mode;
+
+	if (!$self->is_path_ignored($path)) {
+		my ($dir, $file) = ($path =~ m#^(.*?)/?([^/]+)$#);
+		delete $self->{empty}->{$dir};
+		$mode = '100644';
+
+		if ($added_placeholder{$dir}) {
+			# Remove our placeholder file, if we created one.
+			delete_entry($self, $added_placeholder{$dir})
+				unless $path eq $added_placeholder{$dir};
+			delete $added_placeholder{$dir}
+		}
+	}
+
+	{ path => $path, mode_a => $mode, mode_b => $mode,
+	  pool => SVN::Pool->new, action => 'A' };
+}
+
+sub add_directory {
+	my ($self, $path, $cp_path, $cp_rev) = @_;
+	goto out if $self->is_path_ignored($path);
+	my $gpath = $self->git_path($path);
+	if ($gpath eq '') {
+		my ($ls, $ctx) = command_output_pipe(qw/ls-tree
+		                                     -r --name-only -z/,
+				                     $self->{c});
+		while (defined($_ = get_record($ls, "\0"))) {
+			$self->{gii}->remove($_);
+			print "\tD\t$_\n" unless $::_q;
+			push @deleted_gpath, $gpath;
+		}
+		command_close_pipe($ls, $ctx);
+		$self->{empty}->{$path} = 0;
+	}
+	my ($dir, $file) = ($path =~ m#^(.*?)/?([^/]+)$#);
+	delete $self->{empty}->{$dir};
+	$self->{empty}->{$path} = 1;
+
+	if ($added_placeholder{$dir}) {
+		# Remove our placeholder file, if we created one.
+		delete_entry($self, $added_placeholder{$dir});
+		delete $added_placeholder{$dir}
+	}
+
+out:
+	{ path => $path };
+}
+
+sub change_dir_prop {
+	my ($self, $db, $prop, $value) = @_;
+	return undef if $self->is_path_ignored($db->{path});
+	$self->{dir_prop}->{$db->{path}} ||= {};
+	$self->{dir_prop}->{$db->{path}}->{$prop} = $value;
+	undef;
+}
+
+sub absent_directory {
+	my ($self, $path, $pb) = @_;
+	return undef if $self->is_path_ignored($path);
+	$self->{absent_dir}->{$pb->{path}} ||= [];
+	push @{$self->{absent_dir}->{$pb->{path}}}, $path;
+	undef;
+}
+
+sub absent_file {
+	my ($self, $path, $pb) = @_;
+	return undef if $self->is_path_ignored($path);
+	$self->{absent_file}->{$pb->{path}} ||= [];
+	push @{$self->{absent_file}->{$pb->{path}}}, $path;
+	undef;
+}
+
+sub change_file_prop {
+	my ($self, $fb, $prop, $value) = @_;
+	return undef if $self->is_path_ignored($fb->{path});
+	if ($prop eq 'svn:executable') {
+		if ($fb->{mode_b} != 120000) {
+			$fb->{mode_b} = defined $value ? 100755 : 100644;
+		}
+	} elsif ($prop eq 'svn:special') {
+		$fb->{mode_b} = defined $value ? 120000 : 100644;
+	} else {
+		$self->{file_prop}->{$fb->{path}} ||= {};
+		$self->{file_prop}->{$fb->{path}}->{$prop} = $value;
+	}
+	undef;
+}
+
+sub apply_textdelta {
+	my ($self, $fb, $exp) = @_;
+	return undef if $self->is_path_ignored($fb->{path});
+	my $suffix = 0;
+	++$suffix while $::_repository->temp_is_locked("svn_delta_${$}_$suffix");
+	my $fh = $::_repository->temp_acquire("svn_delta_${$}_$suffix");
+	# $fh gets auto-closed() by SVN::TxDelta::apply(),
+	# (but $base does not,) so dup() it for reading in close_file
+	open my $dup, '<&', $fh or croak $!;
+	my $base = $::_repository->temp_acquire("git_blob_${$}_$suffix");
+	# close_file may call temp_acquire on 'svn_hash', but because of the
+	# call chain, if the temp_acquire call from close_file ends up being the
+	# call that first creates the 'svn_hash' temp file, then the FileHandle
+	# that's created as a result will end up in an SVN::Pool that we clear
+	# in SVN::Ra::gs_fetch_loop_common.  Avoid that by making sure the
+	# 'svn_hash' FileHandle is already created before close_file is called.
+	my $tmp_fh = $::_repository->temp_acquire('svn_hash');
+	$::_repository->temp_release($tmp_fh, 1);
+
+	if ($fb->{blob}) {
+		my ($base_is_link, $size);
+
+		if ($fb->{mode_a} eq '120000' &&
+		    ! $self->{empty_symlinks}->{$fb->{path}}) {
+			print $base 'link ' or die "print $!\n";
+			$base_is_link = 1;
+		}
+	retry:
+		$size = $::_repository->cat_blob($fb->{blob}, $base);
+		die "Failed to read object $fb->{blob}" if ($size < 0);
+
+		if (defined $exp) {
+			seek $base, 0, 0 or croak $!;
+			my $got = ::md5sum($base);
+			if ($got ne $exp) {
+				my $err = "Checksum mismatch: ".
+				       "$fb->{path} $fb->{blob}\n" .
+				       "expected: $exp\n" .
+				       "     got: $got\n";
+				if ($base_is_link) {
+					warn $err,
+					     "Retrying... (possibly ",
+					     "a bad symlink from SVN)\n";
+					$::_repository->temp_reset($base);
+					$base_is_link = 0;
+					goto retry;
+				}
+				die $err;
+			}
+		}
+	}
+	seek $base, 0, 0 or croak $!;
+	$fb->{fh} = $fh;
+	$fb->{base} = $base;
+	[ SVN::TxDelta::apply($base, $dup, undef, $fb->{path}, $fb->{pool}) ];
+}
+
+sub close_file {
+	my ($self, $fb, $exp) = @_;
+	return undef if $self->is_path_ignored($fb->{path});
+
+	my $hash;
+	my $path = $self->git_path($fb->{path});
+	if (my $fh = $fb->{fh}) {
+		if (defined $exp) {
+			seek($fh, 0, 0) or croak $!;
+			my $got = ::md5sum($fh);
+			if ($got ne $exp) {
+				die "Checksum mismatch: $path\n",
+				    "expected: $exp\n    got: $got\n";
+			}
+		}
+		if ($fb->{mode_b} == 120000) {
+			sysseek($fh, 0, 0) or croak $!;
+			my $rd = sysread($fh, my $buf, 5);
+
+			if (!defined $rd) {
+				croak "sysread: $!\n";
+			} elsif ($rd == 0) {
+				warn "$path has mode 120000",
+				     " but it points to nothing\n",
+				     "converting to an empty file with mode",
+				     " 100644\n";
+				$fb->{mode_b} = '100644';
+			} elsif ($buf ne 'link ') {
+				warn "$path has mode 120000",
+				     " but is not a link\n";
+			} else {
+				my $tmp_fh = $::_repository->temp_acquire(
+					'svn_hash');
+				my $res;
+				while ($res = sysread($fh, my $str, 1024)) {
+					my $out = syswrite($tmp_fh, $str, $res);
+					defined($out) && $out == $res
+						or croak("write ",
+							Git::temp_path($tmp_fh),
+							": $!\n");
+				}
+				defined $res or croak $!;
+
+				($fh, $tmp_fh) = ($tmp_fh, $fh);
+				Git::temp_release($tmp_fh, 1);
+			}
+		}
+
+		$hash = $::_repository->hash_and_insert_object(
+				Git::temp_path($fh));
+		$hash =~ /^[a-f\d]{40}$/ or die "not a sha1: $hash\n";
+
+		Git::temp_release($fb->{base}, 1);
+		Git::temp_release($fh, 1);
+	} else {
+		$hash = $fb->{blob} or die "no blob information\n";
+	}
+	$fb->{pool}->clear;
+	$self->{gii}->update($fb->{mode_b}, $hash, $path) or croak $!;
+	print "\t$fb->{action}\t$path\n" if $fb->{action} && ! $::_q;
+	undef;
+}
+
+sub abort_edit {
+	my $self = shift;
+	$self->{nr} = $self->{gii}->{nr};
+	delete $self->{gii};
+	$self->SUPER::abort_edit(@_);
+}
+
+sub close_edit {
+	my $self = shift;
+
+	if ($_preserve_empty_dirs) {
+		my @empty_dirs;
+
+		# Any entry flagged as empty that also has an associated
+		# dir_prop represents a newly created empty directory.
+		foreach my $i (keys %{$self->{empty}}) {
+			push @empty_dirs, $i if exists $self->{dir_prop}->{$i};
+		}
+
+		# Search for directories that have become empty due subsequent
+		# file deletes.
+		push @empty_dirs, $self->find_empty_directories();
+
+		# Finally, add a placeholder file to each empty directory.
+		$self->add_placeholder_file($_) foreach (@empty_dirs);
+
+		$self->stash_placeholder_list();
+	}
+
+	$self->{git_commit_ok} = 1;
+	$self->{nr} = $self->{gii}->{nr};
+	delete $self->{gii};
+	$self->SUPER::close_edit(@_);
+}
+
+sub find_empty_directories {
+	my ($self) = @_;
+	my @empty_dirs;
+	my %dirs = map { dirname($_) => 1 } @deleted_gpath;
+
+	foreach my $dir (sort keys %dirs) {
+		next if $dir eq ".";
+
+		# If there have been any additions to this directory, there is
+		# no reason to check if it is empty.
+		my $skip_added = 0;
+		foreach my $t (qw/dir_prop file_prop/) {
+			foreach my $path (keys %{ $self->{$t} }) {
+				if (exists $self->{$t}->{dirname($path)}) {
+					$skip_added = 1;
+					last;
+				}
+			}
+			last if $skip_added;
+		}
+		next if $skip_added;
+
+		# Use `git ls-tree` to get the filenames of this directory
+		# that existed prior to this particular commit.
+		my $ls = command('ls-tree', '-z', '--name-only',
+				 $self->{c}, "$dir/");
+		my %files = map { $_ => 1 } split(/\0/, $ls);
+
+		# Remove the filenames that were deleted during this commit.
+		delete $files{$_} foreach (@deleted_gpath);
+
+		# Report the directory if there are no filenames left.
+		push @empty_dirs, $dir unless (scalar %files);
+	}
+	@empty_dirs;
+}
+
+sub add_placeholder_file {
+	my ($self, $dir) = @_;
+	my $path = "$dir/$_placeholder_filename";
+	my $gpath = $self->git_path($path);
+
+	my $fh = $::_repository->temp_acquire($gpath);
+	my $hash = $::_repository->hash_and_insert_object(Git::temp_path($fh));
+	Git::temp_release($fh, 1);
+	$self->{gii}->update('100644', $hash, $gpath) or croak $!;
+
+	# The directory should no longer be considered empty.
+	delete $self->{empty}->{$dir} if exists $self->{empty}->{$dir};
+
+	# Keep track of any placeholder files we create.
+	$added_placeholder{$dir} = $path;
+}
+
+sub stash_placeholder_list {
+	my ($self) = @_;
+	my $k = "svn-remote.$repo_id.added-placeholder";
+	my $v = eval { command_oneline('config', '--get-all', $k) };
+	command_noisy('config', '--unset-all', $k) if $v;
+	foreach (values %added_placeholder) {
+		command_noisy('config', '--add', $k, $_);
+	}
+}
+
+1;
+__END__
+
+=head1 NAME
+
+Git::SVN::Fetcher - tree delta consumer for "git svn fetch"
+
+=head1 SYNOPSIS
+
+    use SVN::Core;
+    use SVN::Ra;
+    use Git::SVN;
+    use Git::SVN::Fetcher;
+    use Git;
+
+    my $gs = Git::SVN->find_by_url($url);
+    my $ra = SVN::Ra->new(url => $url);
+    my $editor = Git::SVN::Fetcher->new($gs);
+    my $reporter = $ra->do_update($SVN::Core::INVALID_REVNUM, '',
+                                  1, $editor);
+    $reporter->set_path('', $old_rev, 0);
+    $reporter->finish_report;
+    my $tree = $gs->tmp_index_do(sub { command_oneline('write-tree') });
+
+    foreach my $path (keys %{$editor->{dir_prop}) {
+        my $props = $editor->{dir_prop}{$path};
+        foreach my $prop (keys %$props) {
+            print "property $prop at $path changed to $props->{$prop}\n";
+        }
+    }
+    foreach my $path (keys %{$editor->{empty}) {
+        my $action = $editor->{empty}{$path} ? 'added' : 'removed';
+        print "empty directory $path $action\n";
+    }
+    foreach my $path (keys %{$editor->{file_prop}) { ... }
+    foreach my $parent (keys %{$editor->{absent_dir}}) {
+        my @children = @{$editor->{abstent_dir}{$parent}};
+        print "cannot fetch directory $parent/$_: not authorized?\n"
+            foreach @children;
+    }
+    foreach my $parent (keys %{$editor->{absent_file}) { ... }
+
+=head1 DESCRIPTION
+
+This is a subclass of C<SVN::Delta::Editor>, which means it implements
+callbacks to act as a consumer of Subversion tree deltas.  This
+particular implementation of those callbacks is meant to store
+information about the resulting content which B<git svn fetch> could
+use to populate new commits and new entries for F<unhandled.log>.
+More specifically:
+
+=over
+
+=item * Additions, removals, and modifications of files are propagated
+to git-svn's index file F<$GIT_DIR/svn/$refname/index> using
+B<git update-index>.
+
+=item * Changes in Subversion path properties are recorded in the
+C<dir_prop> and C<file_prop> fields (which are hashes).
+
+=item * Addition and removal of empty directories are indicated by
+entries with value 1 and 0 respectively in the C<empty> hash.
+
+=item * Paths that are present but cannot be conveyed (presumably due
+to permissions) are recorded in the C<absent_file> and
+C<absent_dirs> hashes.  For each key, the corresponding value is
+a list of paths under that directory that were present but
+could not be conveyed.
+
+=back
+
+The interface is unstable.  Do not use this module unless you are
+developing git-svn.
+
+=head1 DEPENDENCIES
+
+L<SVN::Delta> from the Subversion perl bindings,
+the core L<Carp> and L<File::Basename> modules,
+and git's L<Git> helper module.
+
+C<Git::SVN::Fetcher> has not been tested using callers other than
+B<git-svn> itself.
+
+=head1 SEE ALSO
+
+L<SVN::Delta>,
+L<Git::SVN::Editor>.
+
+=head1 INCOMPATIBILITIES
+
+None reported.
+
+=head1 BUGS
+
+None.
diff --git a/third_party/git/perl/Git/SVN/GlobSpec.pm b/third_party/git/perl/Git/SVN/GlobSpec.pm
new file mode 100644
index 000000000000..a0a8d1762150
--- /dev/null
+++ b/third_party/git/perl/Git/SVN/GlobSpec.pm
@@ -0,0 +1,65 @@
+package Git::SVN::GlobSpec;
+use strict;
+use warnings;
+
+sub new {
+	my ($class, $glob, $pattern_ok) = @_;
+	my $re = $glob;
+	$re =~ s!/+$!!g; # no need for trailing slashes
+	my (@left, @right, @patterns);
+	my $state = "left";
+	my $die_msg = "Only one set of wildcards " .
+				"(e.g. '*' or '*/*/*') is supported: $glob\n";
+	for my $part (split(m|/|, $glob)) {
+		if ($pattern_ok && $part =~ /[{}]/ &&
+			 $part !~ /^\{[^{}]+\}/) {
+			die "Invalid pattern in '$glob': $part\n";
+		}
+		my $nstars = $part =~ tr/*//;
+		if ($nstars > 1) {
+			die "Only one '*' is allowed in a pattern: '$part'\n";
+		}
+		if ($part =~ /(.*)\*(.*)/) {
+			die $die_msg if $state eq "right";
+			my ($l, $r) = ($1, $2);
+			$state = "pattern";
+			my $pat = quotemeta($l) . '[^/]*' . quotemeta($r);
+			push(@patterns, $pat);
+		} elsif ($pattern_ok && $part =~ /^\{(.*)\}$/) {
+			die $die_msg if $state eq "right";
+			$state = "pattern";
+			my $p = quotemeta($1);
+			$p =~ s/\\,/|/g;
+			push(@patterns, "(?:$p)");
+		} else {
+			if ($state eq "left") {
+				push(@left, $part);
+			} else {
+				push(@right, $part);
+				$state = "right";
+			}
+		}
+	}
+	my $depth = @patterns;
+	if ($depth == 0) {
+		die "One '*' is needed in glob: '$glob'\n";
+	}
+	my $left = join('/', @left);
+	my $right = join('/', @right);
+	$re = join('/', @patterns);
+	$re = join('\/',
+		   grep(length, quotemeta($left),
+                                "($re)(?=/|\$)",
+                                quotemeta($right)));
+	my $left_re = qr/^\/\Q$left\E(\/|$)/;
+	bless { left => $left, right => $right, left_regex => $left_re,
+	        regex => qr/$re/, glob => $glob, depth => $depth }, $class;
+}
+
+sub full_path {
+	my ($self, $path) = @_;
+	return (length $self->{left} ? "$self->{left}/" : '') .
+	       $path . (length $self->{right} ? "/$self->{right}" : '');
+}
+
+1;
diff --git a/third_party/git/perl/Git/SVN/Log.pm b/third_party/git/perl/Git/SVN/Log.pm
new file mode 100644
index 000000000000..664105357c00
--- /dev/null
+++ b/third_party/git/perl/Git/SVN/Log.pm
@@ -0,0 +1,400 @@
+package Git::SVN::Log;
+use strict;
+use warnings;
+use Git::SVN::Utils qw(fatal);
+use Git qw(command
+           command_oneline
+           command_output_pipe
+           command_close_pipe
+           get_tz_offset);
+use POSIX qw/strftime/;
+use constant commit_log_separator => ('-' x 72) . "\n";
+use vars qw/$TZ $limit $color $pager $non_recursive $verbose $oneline
+            %rusers $show_commit $incremental/;
+
+# Option set in git-svn
+our $_git_format;
+
+sub cmt_showable {
+	my ($c) = @_;
+	return 1 if defined $c->{r};
+
+	# big commit message got truncated by the 16k pretty buffer in rev-list
+	if ($c->{l} && $c->{l}->[-1] eq "...\n" &&
+				$c->{a_raw} =~ /\@([a-f\d\-]+)>$/) {
+		@{$c->{l}} = ();
+		my @log = command(qw/cat-file commit/, $c->{c});
+
+		# shift off the headers
+		shift @log while ($log[0] ne '');
+		shift @log;
+
+		# TODO: make $c->{l} not have a trailing newline in the future
+		@{$c->{l}} = map { "$_\n" } grep !/^git-svn-id: /, @log;
+
+		(undef, $c->{r}, undef) = ::extract_metadata(
+				(grep(/^git-svn-id: /, @log))[-1]);
+	}
+	return defined $c->{r};
+}
+
+sub log_use_color {
+	return $color || Git->repository->get_colorbool('color.diff');
+}
+
+sub git_svn_log_cmd {
+	my ($r_min, $r_max, @args) = @_;
+	my $head = 'HEAD';
+	my (@files, @log_opts);
+	foreach my $x (@args) {
+		if ($x eq '--' || @files) {
+			push @files, $x;
+		} else {
+			if (::verify_ref("$x^0")) {
+				$head = $x;
+			} else {
+				push @log_opts, $x;
+			}
+		}
+	}
+
+	my ($url, $rev, $uuid, $gs) = ::working_head_info($head);
+
+	require Git::SVN;
+	$gs ||= Git::SVN->_new;
+	my @cmd = (qw/log --abbrev-commit --pretty=raw --default/,
+	           $gs->refname);
+	push @cmd, '-r' unless $non_recursive;
+	push @cmd, qw/--raw --name-status/ if $verbose;
+	push @cmd, '--color' if log_use_color();
+	push @cmd, @log_opts;
+	if (defined $r_max && $r_max == $r_min) {
+		push @cmd, '--max-count=1';
+		if (my $c = $gs->rev_map_get($r_max)) {
+			push @cmd, $c;
+		}
+	} elsif (defined $r_max) {
+		if ($r_max < $r_min) {
+			($r_min, $r_max) = ($r_max, $r_min);
+		}
+		my (undef, $c_max) = $gs->find_rev_before($r_max, 1, $r_min);
+		my (undef, $c_min) = $gs->find_rev_after($r_min, 1, $r_max);
+		# If there are no commits in the range, both $c_max and $c_min
+		# will be undefined.  If there is at least 1 commit in the
+		# range, both will be defined.
+		return () if !defined $c_min || !defined $c_max;
+		if ($c_min eq $c_max) {
+			push @cmd, '--max-count=1', $c_min;
+		} else {
+			push @cmd, '--boundary', "$c_min..$c_max";
+		}
+	}
+	return (@cmd, @files);
+}
+
+# adapted from pager.c
+sub config_pager {
+	if (! -t *STDOUT) {
+		$ENV{GIT_PAGER_IN_USE} = 'false';
+		$pager = undef;
+		return;
+	}
+	chomp($pager = command_oneline(qw(var GIT_PAGER)));
+	if ($pager eq 'cat') {
+		$pager = undef;
+	}
+	$ENV{GIT_PAGER_IN_USE} = defined($pager);
+}
+
+sub run_pager {
+	return unless defined $pager;
+	pipe my ($rfd, $wfd) or return;
+	defined(my $pid = fork) or fatal "Can't fork: $!";
+	if (!$pid) {
+		open STDOUT, '>&', $wfd or
+		                     fatal "Can't redirect to stdout: $!";
+		return;
+	}
+	open STDIN, '<&', $rfd or fatal "Can't redirect stdin: $!";
+	$ENV{LESS} ||= 'FRX';
+	$ENV{LV} ||= '-c';
+	exec $pager or fatal "Can't run pager: $! ($pager)";
+}
+
+sub format_svn_date {
+	my $t = shift || time;
+	require Git::SVN;
+	my $gmoff = get_tz_offset($t);
+	return strftime("%Y-%m-%d %H:%M:%S $gmoff (%a, %d %b %Y)", localtime($t));
+}
+
+sub parse_git_date {
+	my ($t, $tz) = @_;
+	# Date::Parse isn't in the standard Perl distro :(
+	if ($tz =~ s/^\+//) {
+		$t += tz_to_s_offset($tz);
+	} elsif ($tz =~ s/^\-//) {
+		$t -= tz_to_s_offset($tz);
+	}
+	return $t;
+}
+
+sub set_local_timezone {
+	if (defined $TZ) {
+		$ENV{TZ} = $TZ;
+	} else {
+		delete $ENV{TZ};
+	}
+}
+
+sub tz_to_s_offset {
+	my ($tz) = @_;
+	$tz =~ s/(\d\d)$//;
+	return ($1 * 60) + ($tz * 3600);
+}
+
+sub get_author_info {
+	my ($dest, $author, $t, $tz) = @_;
+	$author =~ s/(?:^\s*|\s*$)//g;
+	$dest->{a_raw} = $author;
+	my $au;
+	if ($::_authors) {
+		$au = $rusers{$author} || undef;
+	}
+	if (!$au) {
+		($au) = ($author =~ /<([^>]+)\@[^>]+>$/);
+	}
+	$dest->{t} = $t;
+	$dest->{tz} = $tz;
+	$dest->{a} = $au;
+	$dest->{t_utc} = parse_git_date($t, $tz);
+}
+
+sub process_commit {
+	my ($c, $r_min, $r_max, $defer) = @_;
+	if (defined $r_min && defined $r_max) {
+		if ($r_min == $c->{r} && $r_min == $r_max) {
+			show_commit($c);
+			return 0;
+		}
+		return 1 if $r_min == $r_max;
+		if ($r_min < $r_max) {
+			# we need to reverse the print order
+			return 0 if (defined $limit && --$limit < 0);
+			push @$defer, $c;
+			return 1;
+		}
+		if ($r_min != $r_max) {
+			return 1 if ($r_min < $c->{r});
+			return 1 if ($r_max > $c->{r});
+		}
+	}
+	return 0 if (defined $limit && --$limit < 0);
+	show_commit($c);
+	return 1;
+}
+
+my $l_fmt;
+sub show_commit {
+	my $c = shift;
+	if ($oneline) {
+		my $x = "\n";
+		if (my $l = $c->{l}) {
+			while ($l->[0] =~ /^\s*$/) { shift @$l }
+			$x = $l->[0];
+		}
+		$l_fmt ||= 'A' . length($c->{r});
+		print 'r',pack($l_fmt, $c->{r}),' | ';
+		print "$c->{c} | " if $show_commit;
+		print $x;
+	} else {
+		show_commit_normal($c);
+	}
+}
+
+sub show_commit_changed_paths {
+	my ($c) = @_;
+	return unless $c->{changed};
+	print "Changed paths:\n", @{$c->{changed}};
+}
+
+sub show_commit_normal {
+	my ($c) = @_;
+	print commit_log_separator, "r$c->{r} | ";
+	print "$c->{c} | " if $show_commit;
+	print "$c->{a} | ", format_svn_date($c->{t_utc}), ' | ';
+	my $nr_line = 0;
+
+	if (my $l = $c->{l}) {
+		while ($l->[$#$l] eq "\n" && $#$l > 0
+		                          && $l->[($#$l - 1)] eq "\n") {
+			pop @$l;
+		}
+		$nr_line = scalar @$l;
+		if (!$nr_line) {
+			print "1 line\n\n\n";
+		} else {
+			if ($nr_line == 1) {
+				$nr_line = '1 line';
+			} else {
+				$nr_line .= ' lines';
+			}
+			print $nr_line, "\n";
+			show_commit_changed_paths($c);
+			print "\n";
+			print $_ foreach @$l;
+		}
+	} else {
+		print "1 line\n";
+		show_commit_changed_paths($c);
+		print "\n";
+
+	}
+	foreach my $x (qw/raw stat diff/) {
+		if ($c->{$x}) {
+			print "\n";
+			print $_ foreach @{$c->{$x}}
+		}
+	}
+}
+
+sub cmd_show_log {
+	my (@args) = @_;
+	my ($r_min, $r_max);
+	my $r_last = -1; # prevent dupes
+	set_local_timezone();
+	if (defined $::_revision) {
+		if ($::_revision =~ /^(\d+):(\d+)$/) {
+			($r_min, $r_max) = ($1, $2);
+		} elsif ($::_revision =~ /^\d+$/) {
+			$r_min = $r_max = $::_revision;
+		} else {
+			fatal "-r$::_revision is not supported, use ",
+				"standard 'git log' arguments instead";
+		}
+	}
+
+	config_pager();
+	@args = git_svn_log_cmd($r_min, $r_max, @args);
+	if (!@args) {
+		print commit_log_separator unless $incremental || $oneline;
+		return;
+	}
+	my $log = command_output_pipe(@args);
+	run_pager();
+	my (@k, $c, $d, $stat);
+	my $esc_color = qr/(?:\033\[(?:(?:\d+;)*\d*)?m)*/;
+	while (<$log>) {
+		if (/^${esc_color}commit (?:- )?($::sha1_short)/o) {
+			my $cmt = $1;
+			if ($c && cmt_showable($c) && $c->{r} != $r_last) {
+				$r_last = $c->{r};
+				process_commit($c, $r_min, $r_max, \@k) or
+								goto out;
+			}
+			$d = undef;
+			$c = { c => $cmt };
+		} elsif (/^${esc_color}author (.+) (\d+) ([\-\+]?\d+)$/o) {
+			get_author_info($c, $1, $2, $3);
+		} elsif (/^${esc_color}(?:tree|parent|committer) /o) {
+			# ignore
+		} elsif (/^${esc_color}:\d{6} \d{6} $::sha1_short/o) {
+			push @{$c->{raw}}, $_;
+		} elsif (/^${esc_color}[ACRMDT]\t/) {
+			# we could add $SVN->{svn_path} here, but that requires
+			# remote access at the moment (repo_path_split)...
+			s#^(${esc_color})([ACRMDT])\t#$1   $2 #o;
+			push @{$c->{changed}}, $_;
+		} elsif (/^${esc_color}diff /o) {
+			$d = 1;
+			push @{$c->{diff}}, $_;
+		} elsif ($d) {
+			push @{$c->{diff}}, $_;
+		} elsif (/^\ .+\ \|\s*\d+\ $esc_color[\+\-]*
+		          $esc_color*[\+\-]*$esc_color$/x) {
+			$stat = 1;
+			push @{$c->{stat}}, $_;
+		} elsif ($stat && /^ \d+ files changed, \d+ insertions/) {
+			push @{$c->{stat}}, $_;
+			$stat = undef;
+		} elsif (/^${esc_color}    (git-svn-id:.+)$/o) {
+			($c->{url}, $c->{r}, undef) = ::extract_metadata($1);
+		} elsif (s/^${esc_color}    //o) {
+			push @{$c->{l}}, $_;
+		}
+	}
+	if ($c && defined $c->{r} && $c->{r} != $r_last) {
+		$r_last = $c->{r};
+		process_commit($c, $r_min, $r_max, \@k);
+	}
+	if (@k) {
+		($r_min, $r_max) = ($r_max, $r_min);
+		process_commit($_, $r_min, $r_max) foreach reverse @k;
+	}
+out:
+	close $log;
+	print commit_log_separator unless $incremental || $oneline;
+}
+
+sub cmd_blame {
+	my $path = pop;
+
+	config_pager();
+	run_pager();
+
+	my ($fh, $ctx, $rev);
+
+	if ($_git_format) {
+		($fh, $ctx) = command_output_pipe('blame', @_, $path);
+		while (my $line = <$fh>) {
+			if ($line =~ /^\^?([[:xdigit:]]+)\s/) {
+				# Uncommitted edits show up as a rev ID of
+				# all zeros, which we can't look up with
+				# cmt_metadata
+				if ($1 !~ /^0+$/) {
+					(undef, $rev, undef) =
+						::cmt_metadata($1);
+					$rev = '0' if (!$rev);
+				} else {
+					$rev = '0';
+				}
+				$rev = sprintf('%-10s', $rev);
+				$line =~ s/^\^?[[:xdigit:]]+(\s)/$rev$1/;
+			}
+			print $line;
+		}
+	} else {
+		($fh, $ctx) = command_output_pipe('blame', '-p', @_, 'HEAD',
+						  '--', $path);
+		my ($sha1);
+		my %authors;
+		my @buffer;
+		my %dsha; #distinct sha keys
+
+		while (my $line = <$fh>) {
+			push @buffer, $line;
+			if ($line =~ /^([[:xdigit:]]{40})\s\d+\s\d+/) {
+				$dsha{$1} = 1;
+			}
+		}
+
+		my $s2r = ::cmt_sha2rev_batch([keys %dsha]);
+
+		foreach my $line (@buffer) {
+			if ($line =~ /^([[:xdigit:]]{40})\s\d+\s\d+/) {
+				$rev = $s2r->{$1};
+				$rev = '0' if (!$rev)
+			}
+			elsif ($line =~ /^author (.*)/) {
+				$authors{$rev} = $1;
+				$authors{$rev} =~ s/\s/_/g;
+			}
+			elsif ($line =~ /^\t(.*)$/) {
+				printf("%6s %10s %s\n", $rev, $authors{$rev}, $1);
+			}
+		}
+	}
+	command_close_pipe($fh, $ctx);
+}
+
+1;
diff --git a/third_party/git/perl/Git/SVN/Memoize/YAML.pm b/third_party/git/perl/Git/SVN/Memoize/YAML.pm
new file mode 100644
index 000000000000..9676b8f2f735
--- /dev/null
+++ b/third_party/git/perl/Git/SVN/Memoize/YAML.pm
@@ -0,0 +1,93 @@
+package Git::SVN::Memoize::YAML;
+use warnings;
+use strict;
+use YAML::Any ();
+
+# based on Memoize::Storable.
+
+sub TIEHASH {
+	my $package = shift;
+	my $filename = shift;
+	my $truehash = (-e $filename) ? YAML::Any::LoadFile($filename) : {};
+	my $self = {FILENAME => $filename, H => $truehash};
+	bless $self => $package;
+}
+
+sub STORE {
+	my $self = shift;
+	$self->{H}{$_[0]} = $_[1];
+}
+
+sub FETCH {
+	my $self = shift;
+	$self->{H}{$_[0]};
+}
+
+sub EXISTS {
+	my $self = shift;
+	exists $self->{H}{$_[0]};
+}
+
+sub DESTROY {
+	my $self = shift;
+	YAML::Any::DumpFile($self->{FILENAME}, $self->{H});
+}
+
+sub SCALAR {
+	my $self = shift;
+	scalar(%{$self->{H}});
+}
+
+sub FIRSTKEY {
+	'Fake hash from Git::SVN::Memoize::YAML';
+}
+
+sub NEXTKEY {
+	undef;
+}
+
+1;
+__END__
+
+=head1 NAME
+
+Git::SVN::Memoize::YAML - store Memoized data in YAML format
+
+=head1 SYNOPSIS
+
+    use Memoize;
+    use Git::SVN::Memoize::YAML;
+
+    tie my %cache => 'Git::SVN::Memoize::YAML', $filename;
+    memoize('slow_function', SCALAR_CACHE => [HASH => \%cache]);
+    slow_function(arguments);
+
+=head1 DESCRIPTION
+
+This module provides a class that can be used to tie a hash to a
+YAML file.  The file is read when the hash is initialized and
+rewritten when the hash is destroyed.
+
+The intent is to allow L<Memoize> to back its cache with a file in
+YAML format, just like L<Memoize::Storable> allows L<Memoize> to
+back its cache with a file in Storable format.  Unlike the Storable
+format, the YAML format is platform-independent and fairly stable.
+
+Carps on error.
+
+=head1 DIAGNOSTICS
+
+See L<YAML::Any>.
+
+=head1 DEPENDENCIES
+
+L<YAML::Any> from CPAN.
+
+=head1 INCOMPATIBILITIES
+
+None reported.
+
+=head1 BUGS
+
+The entire cache is read into a Perl hash when loading the file,
+so this is not very scalable.
diff --git a/third_party/git/perl/Git/SVN/Migration.pm b/third_party/git/perl/Git/SVN/Migration.pm
new file mode 100644
index 000000000000..dc90f6a62142
--- /dev/null
+++ b/third_party/git/perl/Git/SVN/Migration.pm
@@ -0,0 +1,265 @@
+package Git::SVN::Migration;
+# these version numbers do NOT correspond to actual version numbers
+# of git or git-svn.  They are just relative.
+#
+# v0 layout: .git/$id/info/url, refs/heads/$id-HEAD
+#
+# v1 layout: .git/$id/info/url, refs/remotes/$id
+#
+# v2 layout: .git/svn/$id/info/url, refs/remotes/$id
+#
+# v3 layout: .git/svn/$id, refs/remotes/$id
+#            - info/url may remain for backwards compatibility
+#            - this is what we migrate up to this layout automatically,
+#            - this will be used by git svn init on single branches
+# v3.1 layout (auto migrated):
+#            - .rev_db => .rev_db.$UUID, .rev_db will remain as a symlink
+#              for backwards compatibility
+#
+# v4 layout: .git/svn/$repo_id/$id, refs/remotes/$repo_id/$id
+#            - this is only created for newly multi-init-ed
+#              repositories.  Similar in spirit to the
+#              --use-separate-remotes option in git-clone (now default)
+#            - we do not automatically migrate to this (following
+#              the example set by core git)
+#
+# v5 layout: .rev_db.$UUID => .rev_map.$UUID
+#            - newer, more-efficient format that uses 24-bytes per record
+#              with no filler space.
+#            - use xxd -c24 < .rev_map.$UUID to view and debug
+#            - This is a one-way migration, repositories updated to the
+#              new format will not be able to use old git-svn without
+#              rebuilding the .rev_db.  Rebuilding the rev_db is not
+#              possible if noMetadata or useSvmProps are set; but should
+#              be no problem for users that use the (sensible) defaults.
+use strict;
+use warnings;
+use Carp qw/croak/;
+use File::Path qw/mkpath/;
+use File::Basename qw/dirname basename/;
+
+our $_minimize;
+use Git qw(
+	command
+	command_noisy
+	command_output_pipe
+	command_close_pipe
+	command_oneline
+);
+use Git::SVN;
+
+sub migrate_from_v0 {
+	my $git_dir = $ENV{GIT_DIR};
+	return undef unless -d $git_dir;
+	my ($fh, $ctx) = command_output_pipe(qw/rev-parse --symbolic --all/);
+	my $migrated = 0;
+	while (<$fh>) {
+		chomp;
+		my ($id, $orig_ref) = ($_, $_);
+		next unless $id =~ s#^refs/heads/(.+)-HEAD$#$1#;
+		my $info_url = command_oneline(qw(rev-parse --git-path),
+						"$id/info/url");
+		next unless -f $info_url;
+		my $new_ref = "refs/remotes/$id";
+		if (::verify_ref("$new_ref^0")) {
+			print STDERR "W: $orig_ref is probably an old ",
+			             "branch used by an ancient version of ",
+				     "git-svn.\n",
+				     "However, $new_ref also exists.\n",
+				     "We will not be able ",
+				     "to use this branch until this ",
+				     "ambiguity is resolved.\n";
+			next;
+		}
+		print STDERR "Migrating from v0 layout...\n" if !$migrated;
+		print STDERR "Renaming ref: $orig_ref => $new_ref\n";
+		command_noisy('update-ref', $new_ref, $orig_ref);
+		command_noisy('update-ref', '-d', $orig_ref, $orig_ref);
+		$migrated++;
+	}
+	command_close_pipe($fh, $ctx);
+	print STDERR "Done migrating from v0 layout...\n" if $migrated;
+	$migrated;
+}
+
+sub migrate_from_v1 {
+	my $git_dir = $ENV{GIT_DIR};
+	my $migrated = 0;
+	return $migrated unless -d $git_dir;
+	my $svn_dir = Git::SVN::svn_dir();
+
+	# just in case somebody used 'svn' as their $id at some point...
+	return $migrated if -d $svn_dir && ! -f "$svn_dir/info/url";
+
+	print STDERR "Migrating from a git-svn v1 layout...\n";
+	mkpath([$svn_dir]);
+	print STDERR "Data from a previous version of git-svn exists, but\n\t",
+	             "$svn_dir\n\t(required for this version ",
+	             "($::VERSION) of git-svn) does not exist.\n";
+	my ($fh, $ctx) = command_output_pipe(qw/rev-parse --symbolic --all/);
+	while (<$fh>) {
+		my $x = $_;
+		next unless $x =~ s#^refs/remotes/##;
+		chomp $x;
+		my $info_url = command_oneline(qw(rev-parse --git-path),
+						"$x/info/url");
+		next unless -f $info_url;
+		my $u = eval { ::file_to_s($info_url) };
+		next unless $u;
+		my $dn = dirname("$svn_dir/$x");
+		mkpath([$dn]) unless -d $dn;
+		if ($x eq 'svn') { # they used 'svn' as GIT_SVN_ID:
+			mkpath(["$svn_dir/svn"]);
+			print STDERR " - $git_dir/$x/info => ",
+			                "$svn_dir/$x/info\n";
+			rename "$git_dir/$x/info", "$svn_dir/$x/info" or
+			       croak "$!: $x";
+			# don't worry too much about these, they probably
+			# don't exist with repos this old (save for index,
+			# and we can easily regenerate that)
+			foreach my $f (qw/unhandled.log index .rev_db/) {
+				rename "$git_dir/$x/$f", "$svn_dir/$x/$f";
+			}
+		} else {
+			print STDERR " - $git_dir/$x => $svn_dir/$x\n";
+			rename "$git_dir/$x", "$svn_dir/$x" or croak "$!: $x";
+		}
+		$migrated++;
+	}
+	command_close_pipe($fh, $ctx);
+	print STDERR "Done migrating from a git-svn v1 layout\n";
+	$migrated;
+}
+
+sub read_old_urls {
+	my ($l_map, $pfx, $path) = @_;
+	my @dir;
+	foreach (<$path/*>) {
+		if (-r "$_/info/url") {
+			$pfx .= '/' if $pfx && $pfx !~ m!/$!;
+			my $ref_id = $pfx . basename $_;
+			my $url = ::file_to_s("$_/info/url");
+			$l_map->{$ref_id} = $url;
+		} elsif (-d $_) {
+			push @dir, $_;
+		}
+	}
+	my $svn_dir = Git::SVN::svn_dir();
+	foreach (@dir) {
+		my $x = $_;
+		$x =~ s!^\Q$svn_dir\E/!!o;
+		read_old_urls($l_map, $x, $_);
+	}
+}
+
+sub migrate_from_v2 {
+	my @cfg = command(qw/config -l/);
+	return if grep /^svn-remote\..+\.url=/, @cfg;
+	my %l_map;
+	read_old_urls(\%l_map, '', Git::SVN::svn_dir());
+	my $migrated = 0;
+
+	require Git::SVN;
+	foreach my $ref_id (sort keys %l_map) {
+		eval { Git::SVN->init($l_map{$ref_id}, '', undef, $ref_id) };
+		if ($@) {
+			Git::SVN->init($l_map{$ref_id}, '', $ref_id, $ref_id);
+		}
+		$migrated++;
+	}
+	$migrated;
+}
+
+sub minimize_connections {
+	require Git::SVN;
+	require Git::SVN::Ra;
+
+	my $r = Git::SVN::read_all_remotes();
+	my $new_urls = {};
+	my $root_repos = {};
+	foreach my $repo_id (keys %$r) {
+		my $url = $r->{$repo_id}->{url} or next;
+		my $fetch = $r->{$repo_id}->{fetch} or next;
+		my $ra = Git::SVN::Ra->new($url);
+
+		# skip existing cases where we already connect to the root
+		if (($ra->url eq $ra->{repos_root}) ||
+		    ($ra->{repos_root} eq $repo_id)) {
+			$root_repos->{$ra->url} = $repo_id;
+			next;
+		}
+
+		my $root_ra = Git::SVN::Ra->new($ra->{repos_root});
+		my $root_path = $ra->url;
+		$root_path =~ s#^\Q$ra->{repos_root}\E(/|$)##;
+		foreach my $path (keys %$fetch) {
+			my $ref_id = $fetch->{$path};
+			my $gs = Git::SVN->new($ref_id, $repo_id, $path);
+
+			# make sure we can read when connecting to
+			# a higher level of a repository
+			my ($last_rev, undef) = $gs->last_rev_commit;
+			if (!defined $last_rev) {
+				$last_rev = eval {
+					$root_ra->get_latest_revnum;
+				};
+				next if $@;
+			}
+			my $new = $root_path;
+			$new .= length $path ? "/$path" : '';
+			eval {
+				$root_ra->get_log([$new], $last_rev, $last_rev,
+			                          0, 0, 1, sub { });
+			};
+			next if $@;
+			$new_urls->{$ra->{repos_root}}->{$new} =
+			        { ref_id => $ref_id,
+				  old_repo_id => $repo_id,
+				  old_path => $path };
+		}
+	}
+
+	my @emptied;
+	foreach my $url (keys %$new_urls) {
+		# see if we can re-use an existing [svn-remote "repo_id"]
+		# instead of creating a(n ugly) new section:
+		my $repo_id = $root_repos->{$url} || $url;
+
+		my $fetch = $new_urls->{$url};
+		foreach my $path (keys %$fetch) {
+			my $x = $fetch->{$path};
+			Git::SVN->init($url, $path, $repo_id, $x->{ref_id});
+			my $pfx = "svn-remote.$x->{old_repo_id}";
+
+			my $old_fetch = quotemeta("$x->{old_path}:".
+			                          "$x->{ref_id}");
+			command_noisy(qw/config --unset/,
+			              "$pfx.fetch", '^'. $old_fetch . '$');
+			delete $r->{$x->{old_repo_id}}->
+			       {fetch}->{$x->{old_path}};
+			if (!keys %{$r->{$x->{old_repo_id}}->{fetch}}) {
+				command_noisy(qw/config --unset/,
+				              "$pfx.url");
+				push @emptied, $x->{old_repo_id}
+			}
+		}
+	}
+	if (@emptied) {
+		my $file = $ENV{GIT_CONFIG} ||
+			command_oneline(qw(rev-parse --git-path config));
+		print STDERR <<EOF;
+The following [svn-remote] sections in your config file ($file) are empty
+and can be safely removed:
+EOF
+		print STDERR "[svn-remote \"$_\"]\n" foreach @emptied;
+	}
+}
+
+sub migration_check {
+	migrate_from_v0();
+	migrate_from_v1();
+	migrate_from_v2();
+	minimize_connections() if $_minimize;
+}
+
+1;
diff --git a/third_party/git/perl/Git/SVN/Prompt.pm b/third_party/git/perl/Git/SVN/Prompt.pm
new file mode 100644
index 000000000000..e940b08505f1
--- /dev/null
+++ b/third_party/git/perl/Git/SVN/Prompt.pm
@@ -0,0 +1,184 @@
+package Git::SVN::Prompt;
+use strict;
+use warnings;
+require SVN::Core;
+use vars qw/$_no_auth_cache $_username/;
+
+sub simple {
+	my ($cred, $realm, $default_username, $may_save, $pool) = @_;
+	$may_save = undef if $_no_auth_cache;
+	$default_username = $_username if defined $_username;
+	if (defined $default_username && length $default_username) {
+		if (defined $realm && length $realm) {
+			print STDERR "Authentication realm: $realm\n";
+			STDERR->flush;
+		}
+		$cred->username($default_username);
+	} else {
+		username($cred, $realm, $may_save, $pool);
+	}
+	$cred->password(_read_password("Password for '" .
+	                               $cred->username . "': ", $realm));
+	$cred->may_save($may_save);
+	$SVN::_Core::SVN_NO_ERROR;
+}
+
+sub ssl_server_trust {
+	my ($cred, $realm, $failures, $cert_info, $may_save, $pool) = @_;
+	$may_save = undef if $_no_auth_cache;
+	print STDERR "Error validating server certificate for '$realm':\n";
+	{
+		no warnings 'once';
+		# All variables SVN::Auth::SSL::* are used only once,
+		# so we're shutting up Perl warnings about this.
+		if ($failures & $SVN::Auth::SSL::UNKNOWNCA) {
+			print STDERR " - The certificate is not issued ",
+			    "by a trusted authority. Use the\n",
+			    "   fingerprint to validate ",
+			    "the certificate manually!\n";
+		}
+		if ($failures & $SVN::Auth::SSL::CNMISMATCH) {
+			print STDERR " - The certificate hostname ",
+			    "does not match.\n";
+		}
+		if ($failures & $SVN::Auth::SSL::NOTYETVALID) {
+			print STDERR " - The certificate is not yet valid.\n";
+		}
+		if ($failures & $SVN::Auth::SSL::EXPIRED) {
+			print STDERR " - The certificate has expired.\n";
+		}
+		if ($failures & $SVN::Auth::SSL::OTHER) {
+			print STDERR " - The certificate has ",
+			    "an unknown error.\n";
+		}
+	} # no warnings 'once'
+	printf STDERR
+	        "Certificate information:\n".
+	        " - Hostname: %s\n".
+	        " - Valid: from %s until %s\n".
+	        " - Issuer: %s\n".
+	        " - Fingerprint: %s\n",
+	        map $cert_info->$_, qw(hostname valid_from valid_until
+	                               issuer_dname fingerprint);
+	my $choice;
+prompt:
+	my $options = $may_save ?
+	      "(R)eject, accept (t)emporarily or accept (p)ermanently? " :
+	      "(R)eject or accept (t)emporarily? ";
+	STDERR->flush;
+	$choice = lc(substr(Git::prompt("Certificate problem.\n" . $options) || 'R', 0, 1));
+	if ($choice eq 't') {
+		$cred->may_save(undef);
+	} elsif ($choice eq 'r') {
+		return -1;
+	} elsif ($may_save && $choice eq 'p') {
+		$cred->may_save($may_save);
+	} else {
+		goto prompt;
+	}
+	$cred->accepted_failures($failures);
+	$SVN::_Core::SVN_NO_ERROR;
+}
+
+sub ssl_client_cert {
+	my ($cred, $realm, $may_save, $pool) = @_;
+	$may_save = undef if $_no_auth_cache;
+	print STDERR "Client certificate filename: ";
+	STDERR->flush;
+	chomp(my $filename = <STDIN>);
+	$cred->cert_file($filename);
+	$cred->may_save($may_save);
+	$SVN::_Core::SVN_NO_ERROR;
+}
+
+sub ssl_client_cert_pw {
+	my ($cred, $realm, $may_save, $pool) = @_;
+	$may_save = undef if $_no_auth_cache;
+	$cred->password(_read_password("Password: ", $realm));
+	$cred->may_save($may_save);
+	$SVN::_Core::SVN_NO_ERROR;
+}
+
+sub username {
+	my ($cred, $realm, $may_save, $pool) = @_;
+	$may_save = undef if $_no_auth_cache;
+	if (defined $realm && length $realm) {
+		print STDERR "Authentication realm: $realm\n";
+	}
+	my $username;
+	if (defined $_username) {
+		$username = $_username;
+	} else {
+		$username = Git::prompt("Username: ");
+	}
+	$cred->username($username);
+	$cred->may_save($may_save);
+	$SVN::_Core::SVN_NO_ERROR;
+}
+
+sub _read_password {
+	my ($prompt, $realm) = @_;
+	my $password = Git::prompt($prompt, 1);
+	$password;
+}
+
+1;
+__END__
+
+=head1 NAME
+
+Git::SVN::Prompt - authentication callbacks for git-svn
+
+=head1 SYNOPSIS
+
+    use Git::SVN::Prompt qw(simple ssl_client_cert ssl_client_cert_pw
+                            ssl_server_trust username);
+    use SVN::Client ();
+
+    my $cached_simple = SVN::Client::get_simple_provider();
+    my $git_simple = SVN::Client::get_simple_prompt_provider(\&simple, 2);
+    my $cached_ssl = SVN::Client::get_ssl_server_trust_file_provider();
+    my $git_ssl = SVN::Client::get_ssl_server_trust_prompt_provider(
+        \&ssl_server_trust);
+    my $cached_cert = SVN::Client::get_ssl_client_cert_file_provider();
+    my $git_cert = SVN::Client::get_ssl_client_cert_prompt_provider(
+        \&ssl_client_cert, 2);
+    my $cached_cert_pw = SVN::Client::get_ssl_client_cert_pw_file_provider();
+    my $git_cert_pw = SVN::Client::get_ssl_client_cert_pw_prompt_provider(
+        \&ssl_client_cert_pw, 2);
+    my $cached_username = SVN::Client::get_username_provider();
+    my $git_username = SVN::Client::get_username_prompt_provider(
+        \&username, 2);
+
+    my $ctx = new SVN::Client(
+        auth => [
+            $cached_simple, $git_simple,
+            $cached_ssl, $git_ssl,
+            $cached_cert, $git_cert,
+            $cached_cert_pw, $git_cert_pw,
+            $cached_username, $git_username
+        ]);
+
+=head1 DESCRIPTION
+
+This module is an implementation detail of the "git svn" command.
+It implements git-svn's authentication policy.  Do not use it unless
+you are developing git-svn.
+
+The interface will change as git-svn evolves.
+
+=head1 DEPENDENCIES
+
+L<SVN::Core>.
+
+=head1 SEE ALSO
+
+L<SVN::Client>.
+
+=head1 INCOMPATIBILITIES
+
+None reported.
+
+=head1 BUGS
+
+None.
diff --git a/third_party/git/perl/Git/SVN/Ra.pm b/third_party/git/perl/Git/SVN/Ra.pm
new file mode 100644
index 000000000000..56ad9870bcfd
--- /dev/null
+++ b/third_party/git/perl/Git/SVN/Ra.pm
@@ -0,0 +1,708 @@
+package Git::SVN::Ra;
+use vars qw/@ISA $config_dir $_ignore_refs_regex $_log_window_size/;
+use strict;
+use warnings;
+use Memoize;
+use Git::SVN::Utils qw(
+	canonicalize_url
+	canonicalize_path
+	add_path_to_url
+);
+
+use SVN::Ra;
+BEGIN {
+	@ISA = qw(SVN::Ra);
+}
+
+my ($ra_invalid, $can_do_switch, %ignored_err, $RA);
+
+BEGIN {
+	# enforce temporary pool usage for some simple functions
+	no strict 'refs';
+	for my $f (qw/rev_proplist get_latest_revnum get_uuid get_repos_root
+	              get_file/) {
+		my $SUPER = "SUPER::$f";
+		*$f = sub {
+			my $self = shift;
+			my $pool = SVN::Pool->new;
+			my @ret = $self->$SUPER(@_,$pool);
+			$pool->clear;
+			wantarray ? @ret : $ret[0];
+		};
+	}
+}
+
+# serf has a bug that leads to a coredump upon termination if the
+# remote access object is left around (not fixed yet in serf 1.3.1).
+# Explicitly free it to work around the issue.
+END {
+	$RA = undef;
+	$ra_invalid = 1;
+}
+
+sub _auth_providers () {
+	require SVN::Client;
+	my @rv = (
+	  SVN::Client::get_simple_provider(),
+	  SVN::Client::get_ssl_server_trust_file_provider(),
+	  SVN::Client::get_simple_prompt_provider(
+	    \&Git::SVN::Prompt::simple, 2),
+	  SVN::Client::get_ssl_client_cert_file_provider(),
+	  SVN::Client::get_ssl_client_cert_prompt_provider(
+	    \&Git::SVN::Prompt::ssl_client_cert, 2),
+	  SVN::Client::get_ssl_client_cert_pw_file_provider(),
+	  SVN::Client::get_ssl_client_cert_pw_prompt_provider(
+	    \&Git::SVN::Prompt::ssl_client_cert_pw, 2),
+	  SVN::Client::get_username_provider(),
+	  SVN::Client::get_ssl_server_trust_prompt_provider(
+	    \&Git::SVN::Prompt::ssl_server_trust),
+	  SVN::Client::get_username_prompt_provider(
+	    \&Git::SVN::Prompt::username, 2)
+	);
+
+	# earlier 1.6.x versions would segfault, and <= 1.5.x didn't have
+	# this function
+	if (::compare_svn_version('1.6.15') >= 0) {
+		my $config = SVN::Core::config_get_config($config_dir);
+		my ($p, @a);
+		# config_get_config returns all config files from
+		# ~/.subversion, auth_get_platform_specific_client_providers
+		# just wants the config "file".
+		@a = ($config->{'config'}, undef);
+		$p = SVN::Core::auth_get_platform_specific_client_providers(@a);
+		# Insert the return value from
+		# auth_get_platform_specific_providers
+		unshift @rv, @$p;
+	}
+	\@rv;
+}
+
+sub prepare_config_once {
+	SVN::_Core::svn_config_ensure($config_dir, undef);
+	my ($baton, $callbacks) = SVN::Core::auth_open_helper(_auth_providers);
+	my $config = SVN::Core::config_get_config($config_dir);
+	my $conf_t = $config->{'config'};
+
+	no warnings 'once';
+	# The usage of $SVN::_Core::SVN_CONFIG_* variables
+	# produces warnings that variables are used only once.
+	# I had not found the better way to shut them up, so
+	# the warnings of type 'once' are disabled in this block.
+	if (SVN::_Core::svn_config_get_bool($conf_t,
+	    $SVN::_Core::SVN_CONFIG_SECTION_AUTH,
+	    $SVN::_Core::SVN_CONFIG_OPTION_STORE_PASSWORDS,
+	    1) == 0) {
+		my $val = '1';
+		if (::compare_svn_version('1.9.0') < 0) { # pre-SVN r1553823
+			my $dont_store_passwords = 1;
+			$val = bless \$dont_store_passwords, "_p_void";
+		}
+		SVN::_Core::svn_auth_set_parameter($baton,
+		    $SVN::_Core::SVN_AUTH_PARAM_DONT_STORE_PASSWORDS,
+		    $val);
+	}
+	if (SVN::_Core::svn_config_get_bool($conf_t,
+	    $SVN::_Core::SVN_CONFIG_SECTION_AUTH,
+	    $SVN::_Core::SVN_CONFIG_OPTION_STORE_AUTH_CREDS,
+	    1) == 0) {
+		$Git::SVN::Prompt::_no_auth_cache = 1;
+	}
+
+	return ($config, $baton, $callbacks);
+} # no warnings 'once'
+
+INIT {
+	Memoize::memoize '_auth_providers';
+	Memoize::memoize 'prepare_config_once';
+}
+
+sub new {
+	my ($class, $url) = @_;
+	$url = canonicalize_url($url);
+	return $RA if ($RA && $RA->url eq $url);
+
+	::_req_svn();
+
+	$RA = undef;
+	my ($config, $baton, $callbacks) = prepare_config_once();
+	my $self = SVN::Ra->new(url => $url, auth => $baton,
+	                      config => $config,
+			      pool => SVN::Pool->new,
+	                      auth_provider_callbacks => $callbacks);
+	$RA = bless $self, $class;
+
+	# Make sure its canonicalized
+	$self->url($url);
+	$self->{svn_path} = $url;
+	$self->{repos_root} = $self->get_repos_root;
+	$self->{svn_path} =~ s#^\Q$self->{repos_root}\E(/|$)##;
+	$self->{cache} = { check_path => { r => 0, data => {} },
+	                   get_dir => { r => 0, data => {} } };
+
+	return $RA;
+}
+
+sub url {
+	my $self = shift;
+
+	if (@_) {
+		my $url = shift;
+		$self->{url} = canonicalize_url($url);
+		return;
+	}
+
+	return $self->{url};
+}
+
+sub check_path {
+	my ($self, $path, $r) = @_;
+	my $cache = $self->{cache}->{check_path};
+	if ($r == $cache->{r} && exists $cache->{data}->{$path}) {
+		return $cache->{data}->{$path};
+	}
+	my $pool = SVN::Pool->new;
+	my $t = $self->SUPER::check_path($path, $r, $pool);
+	$pool->clear;
+	if ($r != $cache->{r}) {
+		%{$cache->{data}} = ();
+		$cache->{r} = $r;
+	}
+	$cache->{data}->{$path} = $t;
+}
+
+sub get_dir {
+	my ($self, $dir, $r) = @_;
+	my $cache = $self->{cache}->{get_dir};
+	if ($r == $cache->{r}) {
+		if (my $x = $cache->{data}->{$dir}) {
+			return wantarray ? @$x : $x->[0];
+		}
+	}
+	my $pool = SVN::Pool->new;
+	my ($d, undef, $props);
+
+	if (::compare_svn_version('1.4.0') >= 0) {
+		# n.b. in addition to being potentially more efficient,
+		# this works around what appears to be a bug in some
+		# SVN 1.8 versions
+		my $kind = 1; # SVN_DIRENT_KIND
+		($d, undef, $props) = $self->get_dir2($dir, $r, $kind, $pool);
+	} else {
+		($d, undef, $props) = $self->SUPER::get_dir($dir, $r, $pool);
+	}
+	my %dirents = map { $_ => { kind => $d->{$_}->kind } } keys %$d;
+	$pool->clear;
+	if ($r != $cache->{r}) {
+		%{$cache->{data}} = ();
+		$cache->{r} = $r;
+	}
+	$cache->{data}->{$dir} = [ \%dirents, $r, $props ];
+	wantarray ? (\%dirents, $r, $props) : \%dirents;
+}
+
+# get_log(paths, start, end, limit,
+#         discover_changed_paths, strict_node_history, receiver)
+sub get_log {
+	my ($self, @args) = @_;
+	my $pool = SVN::Pool->new;
+
+	# svn_log_changed_path_t objects passed to get_log are likely to be
+	# overwritten even if only the refs are copied to an external variable,
+	# so we should dup the structures in their entirety.  Using an
+	# externally passed pool (instead of our temporary and quickly cleared
+	# pool in Git::SVN::Ra) does not help matters at all...
+	my $receiver = pop @args;
+	my $prefix = "/".$self->{svn_path};
+	$prefix =~ s#/+($)##;
+	my $prefix_regex = qr#^\Q$prefix\E#;
+	push(@args, sub {
+		my ($paths) = $_[0];
+		return &$receiver(@_) unless $paths;
+		$_[0] = ();
+		foreach my $p (keys %$paths) {
+			my $i = $paths->{$p};
+			# Make path relative to our url, not repos_root
+			$p =~ s/$prefix_regex//;
+			my %s = map { $_ => $i->$_; }
+				qw/copyfrom_path copyfrom_rev action/;
+			if ($s{'copyfrom_path'}) {
+				$s{'copyfrom_path'} =~ s/$prefix_regex//;
+				$s{'copyfrom_path'} = canonicalize_path($s{'copyfrom_path'});
+			}
+			$_[0]{$p} = \%s;
+		}
+		&$receiver(@_);
+	});
+
+
+	# the limit parameter was not supported in SVN 1.1.x, so we
+	# drop it.  Therefore, the receiver callback passed to it
+	# is made aware of this limitation by being wrapped if
+	# the limit passed to is being wrapped.
+	if (::compare_svn_version('1.2.0') <= 0) {
+		my $limit = splice(@args, 3, 1);
+		if ($limit > 0) {
+			my $receiver = pop @args;
+			push(@args, sub { &$receiver(@_) if (--$limit >= 0) });
+		}
+	}
+	my $ret = $self->SUPER::get_log(@args, $pool);
+	$pool->clear;
+	$ret;
+}
+
+# uncommon, only for ancient SVN (<= 1.4.2)
+sub trees_match {
+	require IO::File;
+	require SVN::Client;
+	my ($self, $url1, $rev1, $url2, $rev2) = @_;
+	my $ctx = SVN::Client->new(auth => _auth_providers);
+	my $out = IO::File->new_tmpfile;
+
+	# older SVN (1.1.x) doesn't take $pool as the last parameter for
+	# $ctx->diff(), so we'll create a default one
+	my $pool = SVN::Pool->new_default_sub;
+
+	$ra_invalid = 1; # this will open a new SVN::Ra connection to $url1
+	$ctx->diff([], $url1, $rev1, $url2, $rev2, 1, 1, 0, $out, $out);
+	$out->flush;
+	my $ret = (($out->stat)[7] == 0);
+	close $out or croak $!;
+
+	$ret;
+}
+
+sub get_commit_editor {
+	my ($self, $log, $cb, $pool) = @_;
+
+	my @lock = (::compare_svn_version('1.2.0') >= 0) ? (undef, 0) : ();
+	$self->SUPER::get_commit_editor($log, $cb, @lock, $pool);
+}
+
+sub gs_do_update {
+	my ($self, $rev_a, $rev_b, $gs, $editor) = @_;
+	my $new = ($rev_a == $rev_b);
+	my $path = $gs->path;
+
+	if ($new && -e $gs->{index}) {
+		unlink $gs->{index} or die
+		  "Couldn't unlink index: $gs->{index}: $!\n";
+	}
+	my $pool = SVN::Pool->new;
+	$editor->set_path_strip($path);
+	my (@pc) = split m#/#, $path;
+	my $reporter = $self->do_update($rev_b, (@pc ? shift @pc : ''),
+	                                1, $editor, $pool);
+	my @lock = (::compare_svn_version('1.2.0') >= 0) ? (undef) : ();
+
+	# Since we can't rely on svn_ra_reparent being available, we'll
+	# just have to do some magic with set_path to make it so
+	# we only want a partial path.
+	my $sp = '';
+	my $final = join('/', @pc);
+	while (@pc) {
+		$reporter->set_path($sp, $rev_b, 0, @lock, $pool);
+		$sp .= '/' if length $sp;
+		$sp .= shift @pc;
+	}
+	die "BUG: '$sp' != '$final'\n" if ($sp ne $final);
+
+	$reporter->set_path($sp, $rev_a, $new, @lock, $pool);
+
+	$reporter->finish_report($pool);
+	$pool->clear;
+	$editor->{git_commit_ok};
+}
+
+# this requires SVN 1.4.3 or later (do_switch didn't work before 1.4.3, and
+# svn_ra_reparent didn't work before 1.4)
+sub gs_do_switch {
+	my ($self, $rev_a, $rev_b, $gs, $url_b, $editor) = @_;
+	my $path = $gs->path;
+	my $pool = SVN::Pool->new;
+
+	my $old_url = $self->url;
+	my $full_url = add_path_to_url( $self->url, $path );
+	my ($ra, $reparented);
+
+	if ($old_url =~ m#^svn(\+\w+)?://# ||
+	    ($full_url =~ m#^https?://# &&
+	     canonicalize_url($full_url) ne $full_url)) {
+		$_[0] = undef;
+		$self = undef;
+		$RA = undef;
+		$ra = Git::SVN::Ra->new($full_url);
+		$ra_invalid = 1;
+	} elsif ($old_url ne $full_url) {
+		SVN::_Ra::svn_ra_reparent(
+			$self->{session},
+			canonicalize_url($full_url),
+			$pool
+		);
+		$self->url($full_url);
+		$reparented = 1;
+	}
+
+	$ra ||= $self;
+	$url_b = canonicalize_url($url_b);
+	my $reporter = $ra->do_switch($rev_b, '', 1, $url_b, $editor, $pool);
+	my @lock = (::compare_svn_version('1.2.0') >= 0) ? (undef) : ();
+	$reporter->set_path('', $rev_a, 0, @lock, $pool);
+	$reporter->finish_report($pool);
+
+	if ($reparented) {
+		SVN::_Ra::svn_ra_reparent($self->{session}, $old_url, $pool);
+		$self->url($old_url);
+	}
+
+	$pool->clear;
+	$editor->{git_commit_ok};
+}
+
+sub longest_common_path {
+	my ($gsv, $globs) = @_;
+	my %common;
+	my $common_max = scalar @$gsv;
+
+	foreach my $gs (@$gsv) {
+		my @tmp = split m#/#, $gs->path;
+		my $p = '';
+		foreach (@tmp) {
+			$p .= length($p) ? "/$_" : $_;
+			$common{$p} ||= 0;
+			$common{$p}++;
+		}
+	}
+	$globs ||= [];
+	$common_max += scalar @$globs;
+	foreach my $glob (@$globs) {
+		my @tmp = split m#/#, $glob->{path}->{left};
+		my $p = '';
+		foreach (@tmp) {
+			$p .= length($p) ? "/$_" : $_;
+			$common{$p} ||= 0;
+			$common{$p}++;
+		}
+	}
+
+	my $longest_path = '';
+	foreach (sort {length $b <=> length $a} keys %common) {
+		if ($common{$_} == $common_max) {
+			$longest_path = $_;
+			last;
+		}
+	}
+	$longest_path;
+}
+
+sub gs_fetch_loop_common {
+	my ($self, $base, $head, $gsv, $globs) = @_;
+	return if ($base > $head);
+	# Make sure the cat_blob open2 FileHandle is created before calling
+	# SVN::Pool::new_default so that it does not incorrectly end up in the pool.
+	$::_repository->_open_cat_blob_if_needed;
+	my $gpool = SVN::Pool->new_default;
+	my $ra_url = $self->url;
+	my $reload_ra = sub {
+		$_[0] = undef;
+		$self = undef;
+		$RA = undef;
+		$gpool->clear;
+		$self = Git::SVN::Ra->new($ra_url);
+		$ra_invalid = undef;
+	};
+	my $inc = $_log_window_size;
+	my ($min, $max) = ($base, $head < $base + $inc ? $head : $base + $inc);
+	my $longest_path = longest_common_path($gsv, $globs);
+	my $find_trailing_edge;
+	while (1) {
+		my %revs;
+		my $err;
+		my $err_handler = $SVN::Error::handler;
+		$SVN::Error::handler = sub {
+			($err) = @_;
+			skip_unknown_revs($err);
+		};
+		sub _cb {
+			my ($paths, $r, $author, $date, $log) = @_;
+			[ $paths,
+			  { author => $author, date => $date, log => $log } ];
+		}
+		$self->get_log([$longest_path], $min, $max, 0, 1, 1,
+		               sub { $revs{$_[1]} = _cb(@_) });
+		if ($err) {
+			print "Checked through r$max\r";
+		} else {
+			$find_trailing_edge = 1;
+		}
+		if ($err and $find_trailing_edge) {
+			print STDERR "Path '$longest_path' ",
+				     "was probably deleted:\n",
+				     $err->expanded_message,
+				     "\nWill attempt to follow ",
+				     "revisions r$min .. r$max ",
+				     "committed before the deletion\n";
+			my $hi = $max;
+			while (--$hi >= $min) {
+				my $ok;
+				$self->get_log([$longest_path], $min, $hi,
+				               0, 1, 1, sub {
+				               $ok = $_[1];
+				               $revs{$_[1]} = _cb(@_) });
+				if ($ok) {
+					print STDERR "r$min .. r$ok OK\n";
+					last;
+				}
+			}
+			$find_trailing_edge = 0;
+		}
+		$SVN::Error::handler = $err_handler;
+
+		my %exists = map { $_->path => $_ } @$gsv;
+		foreach my $r (sort {$a <=> $b} keys %revs) {
+			my ($paths, $logged) = @{delete $revs{$r}};
+
+			foreach my $gs ($self->match_globs(\%exists, $paths,
+			                                   $globs, $r)) {
+				if ($gs->rev_map_max >= $r) {
+					next;
+				}
+				next unless $gs->match_paths($paths, $r);
+				$gs->{logged_rev_props} = $logged;
+				if (my $last_commit = $gs->last_commit) {
+					$gs->assert_index_clean($last_commit);
+				}
+				my $log_entry = $gs->do_fetch($paths, $r);
+				if ($log_entry) {
+					$gs->do_git_commit($log_entry);
+				}
+				$Git::SVN::INDEX_FILES{$gs->{index}} = 1;
+			}
+			foreach my $g (@$globs) {
+				my $k = "svn-remote.$g->{remote}." .
+				        "$g->{t}-maxRev";
+				Git::SVN::tmp_config($k, $r);
+			}
+			$reload_ra->() if $ra_invalid;
+		}
+		# pre-fill the .rev_db since it'll eventually get filled in
+		# with '0' x40 if something new gets committed
+		foreach my $gs (@$gsv) {
+			next if $gs->rev_map_max >= $max;
+			next if defined $gs->rev_map_get($max);
+			$gs->rev_map_set($max, 0 x40);
+		}
+		foreach my $g (@$globs) {
+			my $k = "svn-remote.$g->{remote}.$g->{t}-maxRev";
+			Git::SVN::tmp_config($k, $max);
+		}
+		last if $max >= $head;
+		$min = $max + 1;
+		$max += $inc;
+		$max = $head if ($max > $head);
+
+		$reload_ra->();
+	}
+	Git::SVN::gc();
+}
+
+sub get_dir_globbed {
+	my ($self, $left, $depth, $r) = @_;
+
+	my @x = eval { $self->get_dir($left, $r) };
+	return unless scalar @x == 3;
+	my $dirents = $x[0];
+	my @finalents;
+	foreach my $de (keys %$dirents) {
+		next if $dirents->{$de}->{kind} != $SVN::Node::dir;
+		if ($depth > 1) {
+			my @args = ("$left/$de", $depth - 1, $r);
+			foreach my $dir ($self->get_dir_globbed(@args)) {
+				push @finalents, "$de/$dir";
+			}
+		} else {
+			push @finalents, $de;
+		}
+	}
+	@finalents;
+}
+
+# return value: 0 -- don't ignore, 1 -- ignore
+sub is_ref_ignored {
+	my ($g, $p) = @_;
+	my $refname = $g->{ref}->full_path($p);
+	return 1 if defined($g->{ignore_refs_regex}) &&
+	            $refname =~ m!$g->{ignore_refs_regex}!;
+	return 0 unless defined($_ignore_refs_regex);
+	return 1 if $refname =~ m!$_ignore_refs_regex!o;
+	return 0;
+}
+
+sub match_globs {
+	my ($self, $exists, $paths, $globs, $r) = @_;
+
+	sub get_dir_check {
+		my ($self, $exists, $g, $r) = @_;
+
+		my @dirs = $self->get_dir_globbed($g->{path}->{left},
+		                                  $g->{path}->{depth},
+		                                  $r);
+
+		foreach my $de (@dirs) {
+			my $p = $g->{path}->full_path($de);
+			next if $exists->{$p};
+			next if (length $g->{path}->{right} &&
+				 ($self->check_path($p, $r) !=
+				  $SVN::Node::dir));
+			next unless $p =~ /$g->{path}->{regex}/;
+			$exists->{$p} = Git::SVN->init($self->url, $p, undef,
+					 $g->{ref}->full_path($de), 1);
+		}
+	}
+	foreach my $g (@$globs) {
+		if (my $path = $paths->{"/$g->{path}->{left}"}) {
+			if ($path->{action} =~ /^[AR]$/) {
+				get_dir_check($self, $exists, $g, $r);
+			}
+		}
+		foreach (keys %$paths) {
+			if (/$g->{path}->{left_regex}/ &&
+			    !/$g->{path}->{regex}/) {
+				next if $paths->{$_}->{action} !~ /^[AR]$/;
+				get_dir_check($self, $exists, $g, $r);
+			}
+			next unless /$g->{path}->{regex}/;
+			my $p = $1;
+			my $pathname = $g->{path}->full_path($p);
+			next if is_ref_ignored($g, $p);
+			next if $exists->{$pathname};
+			next if ($self->check_path($pathname, $r) !=
+			         $SVN::Node::dir);
+			$exists->{$pathname} = Git::SVN->init(
+			                      $self->url, $pathname, undef,
+			                      $g->{ref}->full_path($p), 1);
+		}
+		my $c = '';
+		foreach (split m#/#, $g->{path}->{left}) {
+			$c .= "/$_";
+			next unless ($paths->{$c} &&
+			             ($paths->{$c}->{action} =~ /^[AR]$/));
+			get_dir_check($self, $exists, $g, $r);
+		}
+	}
+	values %$exists;
+}
+
+sub minimize_url {
+	my ($self) = @_;
+	return $self->url if ($self->url eq $self->{repos_root});
+	my $url = $self->{repos_root};
+	my @components = split(m!/!, $self->{svn_path});
+	my $c = '';
+	do {
+		$url = add_path_to_url($url, $c);
+		eval {
+			my $ra = (ref $self)->new($url);
+			my $latest = $ra->get_latest_revnum;
+			$ra->get_log("", $latest, 0, 1, 0, 1, sub {});
+		};
+	} while ($@ && defined($c = shift @components));
+
+	return canonicalize_url($url);
+}
+
+sub can_do_switch {
+	my $self = shift;
+	unless (defined $can_do_switch) {
+		my $pool = SVN::Pool->new;
+		my $rep = eval {
+			$self->do_switch(1, '', 0, $self->url,
+			                 SVN::Delta::Editor->new, $pool);
+		};
+		if ($@) {
+			$can_do_switch = 0;
+		} else {
+			$rep->abort_report($pool);
+			$can_do_switch = 1;
+		}
+		$pool->clear;
+	}
+	$can_do_switch;
+}
+
+sub skip_unknown_revs {
+	my ($err) = @_;
+	my $errno = $err->apr_err();
+	# Maybe the branch we're tracking didn't
+	# exist when the repo started, so it's
+	# not an error if it doesn't, just continue
+	#
+	# Wonderfully consistent library, eh?
+	# 160013 - svn:// and file://
+	# 175002 - http(s)://
+	# 175007 - http(s):// (this repo required authorization, too...)
+	#   More codes may be discovered later...
+	if ($errno == 175007 || $errno == 175002 || $errno == 160013) {
+		my $err_key = $err->expanded_message;
+		# revision numbers change every time, filter them out
+		$err_key =~ s/\d+/\0/g;
+		$err_key = "$errno\0$err_key";
+		unless ($ignored_err{$err_key}) {
+			warn "W: Ignoring error from SVN, path probably ",
+			     "does not exist: ($errno): ",
+			     $err->expanded_message,"\n";
+			warn "W: Do not be alarmed at the above message ",
+			     "git-svn is just searching aggressively for ",
+			     "old history.\n",
+			     "This may take a while on large repositories\n";
+			$ignored_err{$err_key} = 1;
+		}
+		return;
+	}
+	die "Error from SVN, ($errno): ", $err->expanded_message,"\n";
+}
+
+1;
+__END__
+
+=head1 NAME
+
+Git::SVN::Ra - Subversion remote access functions for git-svn
+
+=head1 SYNOPSIS
+
+    use Git::SVN::Ra;
+
+    my $ra = Git::SVN::Ra->new($branchurl);
+    my ($dirents, $fetched_revnum, $props) =
+        $ra->get_dir('.', $SVN::Core::INVALID_REVNUM);
+
+=head1 DESCRIPTION
+
+This is a wrapper around the L<SVN::Ra> module for use by B<git-svn>.
+It fills in some default parameters (such as the authentication
+scheme), smooths over incompatibilities between libsvn versions, adds
+caching, and implements some functions specific to B<git-svn>.
+
+Do not use it unless you are developing git-svn.  The interface will
+change as git-svn evolves.
+
+=head1 DEPENDENCIES
+
+Subversion perl bindings,
+L<Git::SVN>.
+
+C<Git::SVN::Ra> has not been tested using callers other than
+B<git-svn> itself.
+
+=head1 SEE ALSO
+
+L<SVN::Ra>.
+
+=head1 INCOMPATIBILITIES
+
+None reported.
+
+=head1 BUGS
+
+None.
diff --git a/third_party/git/perl/Git/SVN/Utils.pm b/third_party/git/perl/Git/SVN/Utils.pm
new file mode 100644
index 000000000000..3d1a0933a2eb
--- /dev/null
+++ b/third_party/git/perl/Git/SVN/Utils.pm
@@ -0,0 +1,232 @@
+package Git::SVN::Utils;
+
+use strict;
+use warnings;
+
+use SVN::Core;
+
+use base qw(Exporter);
+
+our @EXPORT_OK = qw(
+	fatal
+	can_compress
+	canonicalize_path
+	canonicalize_url
+	join_paths
+	add_path_to_url
+);
+
+
+=head1 NAME
+
+Git::SVN::Utils - utility functions used across Git::SVN
+
+=head1 SYNOPSIS
+
+    use Git::SVN::Utils qw(functions to import);
+
+=head1 DESCRIPTION
+
+This module contains functions which are useful across many different
+parts of Git::SVN.  Mostly it's a place to put utility functions
+rather than duplicate the code or have classes grabbing at other
+classes.
+
+=head1 FUNCTIONS
+
+All functions can be imported only on request.
+
+=head3 fatal
+
+    fatal(@message);
+
+Display a message and exit with a fatal error code.
+
+=cut
+
+# Note: not certain why this is in use instead of die.  Probably because
+# the exit code of die is 255?  Doesn't appear to be used consistently.
+sub fatal (@) { print STDERR "@_\n"; exit 1 }
+
+
+=head3 can_compress
+
+    my $can_compress = can_compress;
+
+Returns true if Compress::Zlib is available, false otherwise.
+
+=cut
+
+my $can_compress;
+sub can_compress {
+	return $can_compress if defined $can_compress;
+
+	return $can_compress = eval { require Compress::Zlib; };
+}
+
+
+=head3 canonicalize_path
+
+    my $canoncalized_path = canonicalize_path($path);
+
+Converts $path into a canonical form which is safe to pass to the SVN
+API as a file path.
+
+=cut
+
+# Turn foo/../bar into bar
+sub _collapse_dotdot {
+	my $path = shift;
+
+	1 while $path =~ s{/[^/]+/+\.\.}{};
+	1 while $path =~ s{[^/]+/+\.\./}{};
+	1 while $path =~ s{[^/]+/+\.\.}{};
+
+	return $path;
+}
+
+
+sub canonicalize_path {
+	my $path = shift;
+	my $rv;
+
+	# The 1.7 way to do it
+	if ( defined &SVN::_Core::svn_dirent_canonicalize ) {
+		$path = _collapse_dotdot($path);
+		$rv = SVN::_Core::svn_dirent_canonicalize($path);
+	}
+	# The 1.6 way to do it
+	# This can return undef on subversion-perl-1.4.2-2.el5 (CentOS 5.2)
+	elsif ( defined &SVN::_Core::svn_path_canonicalize ) {
+		$path = _collapse_dotdot($path);
+		$rv = SVN::_Core::svn_path_canonicalize($path);
+	}
+
+	return $rv if defined $rv;
+
+	# No SVN API canonicalization is available, or the SVN API
+	# didn't return a successful result, do it ourselves
+	return _canonicalize_path_ourselves($path);
+}
+
+
+sub _canonicalize_path_ourselves {
+	my ($path) = @_;
+	my $dot_slash_added = 0;
+	if (substr($path, 0, 1) ne "/") {
+		$path = "./" . $path;
+		$dot_slash_added = 1;
+	}
+	$path =~ s#/+#/#g;
+	$path =~ s#/\.(?:/|$)#/#g;
+	$path = _collapse_dotdot($path);
+	$path =~ s#/$##g;
+	$path =~ s#^\./## if $dot_slash_added;
+	$path =~ s#^\.$##;
+	return $path;
+}
+
+
+=head3 canonicalize_url
+
+    my $canonicalized_url = canonicalize_url($url);
+
+Converts $url into a canonical form which is safe to pass to the SVN
+API as a URL.
+
+=cut
+
+sub canonicalize_url {
+	my $url = shift;
+
+	# The 1.7 way to do it
+	if ( defined &SVN::_Core::svn_uri_canonicalize ) {
+		return SVN::_Core::svn_uri_canonicalize($url);
+	}
+	# There wasn't a 1.6 way to do it, so we do it ourself.
+	else {
+		return _canonicalize_url_ourselves($url);
+	}
+}
+
+
+sub _canonicalize_url_path {
+	my ($uri_path) = @_;
+
+	my @parts;
+	foreach my $part (split m{/+}, $uri_path) {
+		$part =~ s/([^!\$%&'()*+,.\/\w:=\@_`~-]|%(?![a-fA-F0-9]{2}))/sprintf("%%%02X",ord($1))/eg;
+		push @parts, $part;
+	}
+
+	return join('/', @parts);
+}
+
+sub _canonicalize_url_ourselves {
+	my ($url) = @_;
+	if ($url =~ m#^([^:]+)://([^/]*)(.*)$#) {
+		my ($scheme, $domain, $uri) = ($1, $2, _canonicalize_url_path(canonicalize_path($3)));
+		$url = "$scheme://$domain$uri";
+	}
+	$url;
+}
+
+
+=head3 join_paths
+
+    my $new_path = join_paths(@paths);
+
+Appends @paths together into a single path.  Any empty paths are ignored.
+
+=cut
+
+sub join_paths {
+	my @paths = @_;
+
+	@paths = grep { defined $_ && length $_ } @paths;
+
+	return '' unless @paths;
+	return $paths[0] if @paths == 1;
+
+	my $new_path = shift @paths;
+	$new_path =~ s{/+$}{};
+
+	my $last_path = pop @paths;
+	$last_path =~ s{^/+}{};
+
+	for my $path (@paths) {
+		$path =~ s{^/+}{};
+		$path =~ s{/+$}{};
+		$new_path .= "/$path";
+	}
+
+	return $new_path .= "/$last_path";
+}
+
+
+=head3 add_path_to_url
+
+    my $new_url = add_path_to_url($url, $path);
+
+Appends $path onto the $url.  If $path is empty, $url is returned unchanged.
+
+=cut
+
+sub add_path_to_url {
+	my($url, $path) = @_;
+
+	return $url if !defined $path or !length $path;
+
+	# Strip trailing and leading slashes so we don't
+	# wind up with http://x.com///path
+	$url  =~ s{/+$}{};
+	$path =~ s{^/+}{};
+
+	# If a path has a % in it, URI escape it so it's not
+	# mistaken for a URI escape later.
+	$path =~ s{%}{%25}g;
+
+	return join '/', $url, $path;
+}
+
+1;
diff --git a/third_party/git/perl/header_templates/fixed_prefix.template.pl b/third_party/git/perl/header_templates/fixed_prefix.template.pl
new file mode 100644
index 000000000000..857b4391a499
--- /dev/null
+++ b/third_party/git/perl/header_templates/fixed_prefix.template.pl
@@ -0,0 +1 @@
+use lib (split(/@@PATHSEP@@/, $ENV{GITPERLLIB} || '@@INSTLIBDIR@@'));
diff --git a/third_party/git/perl/header_templates/runtime_prefix.template.pl b/third_party/git/perl/header_templates/runtime_prefix.template.pl
new file mode 100644
index 000000000000..9d28b3d8636c
--- /dev/null
+++ b/third_party/git/perl/header_templates/runtime_prefix.template.pl
@@ -0,0 +1,42 @@
+# BEGIN RUNTIME_PREFIX generated code.
+#
+# This finds our Git::* libraries relative to the script's runtime path.
+sub __git_system_path {
+	my ($relpath) = @_;
+	my $gitexecdir_relative = '@@GITEXECDIR_REL@@';
+
+	# GIT_EXEC_PATH is supplied by `git` or the test suite.
+	my $exec_path;
+	if (exists $ENV{GIT_EXEC_PATH}) {
+		$exec_path = $ENV{GIT_EXEC_PATH};
+	} else {
+		# This can happen if this script is being directly invoked instead of run
+		# by "git".
+		require FindBin;
+		$exec_path = $FindBin::Bin;
+	}
+
+	# Trim off the relative gitexecdir path to get the system path.
+	(my $prefix = $exec_path) =~ s/\Q$gitexecdir_relative\E$//;
+
+	require File::Spec;
+	return File::Spec->catdir($prefix, $relpath);
+}
+
+BEGIN {
+	use lib split /@@PATHSEP@@/,
+	(
+		$ENV{GITPERLLIB} ||
+		do {
+			my $perllibdir = __git_system_path('@@PERLLIBDIR_REL@@');
+			(-e $perllibdir) || die("Invalid system path ($relpath): $path");
+			$perllibdir;
+		}
+	);
+
+	# Export the system locale directory to the I18N module. The locale directory
+	# is only installed if NO_GETTEXT is set.
+	$Git::I18N::TEXTDOMAINDIR = __git_system_path('@@LOCALEDIR_REL@@');
+}
+
+# END RUNTIME_PREFIX generated code.