merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 82 insertions, 65 deletions

diff --git a/third_party/git/git-gui/lib/choose_repository.tcl b/third_party/git/git-gui/lib/choose_repository.tcl
index 80f5a59bbbfc..af1fee7c751d 100644
--- a/third_party/git/git-gui/lib/choose_repository.tcl
+++ b/third_party/git/git-gui/lib/choose_repository.tcl
@@ -9,6 +9,18 @@ field w_body      ; # Widget holding the center content
 field w_next      ; # Next button
 field w_quit      ; # Quit button
 field o_cons      ; # Console object (if active)
+
+# Status mega-widget instance during _do_clone2 (used by _copy_files and
+# _link_files). Widget is destroyed before _do_clone2 calls
+# _do_clone_checkout
+field o_status
+
+# Operation displayed by status mega-widget during _do_clone_checkout =>
+# _readtree_wait => _postcheckout_wait => _do_clone_submodules =>
+# _do_validate_submodule_cloning. The status mega-widget is a different
+# instance than that stored in $o_status in earlier operations.
+field o_status_op
+
 field w_types     ; # List of type buttons in clone
 field w_recentlist ; # Listbox containing recent repositories
 field w_localpath  ; # Entry widget bound to local_path
@@ -345,31 +357,10 @@ proc _is_git {path {outdir_var ""}} {
 	if {$outdir_var ne ""} {
 		upvar 1 $outdir_var outdir
 	}
-	if {[file isfile $path]} {
-		set fp [open $path r]
-		gets $fp line
-		close $fp
-		if {[regexp "^gitdir: (.+)$" $line line link_target]} {
-			set path [file join [file dirname $path] $link_target]
-			set path [file normalize $path]
-		}
-	}
-
-	if {[file exists [file join $path HEAD]]
-	 && [file exists [file join $path objects]]
-	 && [file exists [file join $path config]]} {
-		set outdir $path
-		return 1
-	}
-	if {[is_Cygwin]} {
-		if {[file exists [file join $path HEAD]]
-		 && [file exists [file join $path objects.lnk]]
-		 && [file exists [file join $path config.lnk]]} {
-			set outdir $path
-			return 1
-		}
+	if {[catch {set outdir [git rev-parse --resolve-git-dir $path]}]} {
+		return 0
 	}
-	return 0
+	return 1
 }
 
 proc _objdir {path} {
@@ -659,12 +650,12 @@ method _do_clone2 {} {
 
 	switch -exact -- $clone_type {
 	hardlink {
-		set o_cons [status_bar::two_line $w_body]
+		set o_status [status_bar::two_line $w_body]
 		pack $w_body -fill x -padx 10 -pady 10
 
-		$o_cons start \
+		set status_op [$o_status start \
 			[mc "Counting objects"] \
-			[mc "buckets"]
+			[mc "buckets"]]
 		update
 
 		if {[file exists [file join $objdir info alternates]]} {
@@ -689,6 +680,7 @@ method _do_clone2 {} {
 			} err]} {
 				catch {cd $pwd}
 				_clone_failed $this [mc "Unable to copy objects/info/alternates: %s" $err]
+				$status_op stop
 				return
 			}
 		}
@@ -700,7 +692,7 @@ method _do_clone2 {} {
 			-directory [file join $objdir] ??]
 		set bcnt [expr {[llength $buckets] + 2}]
 		set bcur 1
-		$o_cons update $bcur $bcnt
+		$status_op update $bcur $bcnt
 		update
 
 		file mkdir [file join .git objects pack]
@@ -708,7 +700,7 @@ method _do_clone2 {} {
 			-directory [file join $objdir pack] *] {
 			lappend tolink [file join pack $i]
 		}
-		$o_cons update [incr bcur] $bcnt
+		$status_op update [incr bcur] $bcnt
 		update
 
 		foreach i $buckets {
@@ -717,10 +709,10 @@ method _do_clone2 {} {
 				-directory [file join $objdir $i] *] {
 				lappend tolink [file join $i $j]
 			}
-			$o_cons update [incr bcur] $bcnt
+			$status_op update [incr bcur] $bcnt
 			update
 		}
-		$o_cons stop
+		$status_op stop
 
 		if {$tolink eq {}} {
 			info_popup [strcat \
@@ -747,6 +739,8 @@ method _do_clone2 {} {
 		if {!$i} return
 
 		destroy $w_body
+
+		set o_status {}
 	}
 	full {
 		set o_cons [console::embed \
@@ -781,9 +775,9 @@ method _do_clone2 {} {
 }
 
 method _copy_files {objdir tocopy} {
-	$o_cons start \
+	set status_op [$o_status start \
 		[mc "Copying objects"] \
-		[mc "KiB"]
+		[mc "KiB"]]
 	set tot 0
 	set cmp 0
 	foreach p $tocopy {
@@ -798,7 +792,7 @@ method _copy_files {objdir tocopy} {
 
 				while {![eof $f_in]} {
 					incr cmp [fcopy $f_in $f_cp -size 16384]
-					$o_cons update \
+					$status_op update \
 						[expr {$cmp / 1024}] \
 						[expr {$tot / 1024}]
 					update
@@ -808,17 +802,19 @@ method _copy_files {objdir tocopy} {
 				close $f_cp
 			} err]} {
 			_clone_failed $this [mc "Unable to copy object: %s" $err]
+			$status_op stop
 			return 0
 		}
 	}
+	$status_op stop
 	return 1
 }
 
 method _link_files {objdir tolink} {
 	set total [llength $tolink]
-	$o_cons start \
+	set status_op [$o_status start \
 		[mc "Linking objects"] \
-		[mc "objects"]
+		[mc "objects"]]
 	for {set i 0} {$i < $total} {} {
 		set p [lindex $tolink $i]
 		if {[catch {
@@ -827,15 +823,17 @@ method _link_files {objdir tolink} {
 					[file join $objdir $p]
 			} err]} {
 			_clone_failed $this [mc "Unable to hardlink object: %s" $err]
+			$status_op stop
 			return 0
 		}
 
 		incr i
 		if {$i % 5 == 0} {
-			$o_cons update $i $total
+			$status_op update $i $total
 			update
 		}
 	}
+	$status_op stop
 	return 1
 }
 
@@ -958,11 +956,26 @@ method _do_clone_checkout {HEAD} {
 		return
 	}
 
-	set o_cons [status_bar::two_line $w_body]
+	set status [status_bar::two_line $w_body]
 	pack $w_body -fill x -padx 10 -pady 10
-	$o_cons start \
+
+	# We start the status operation here.
+	#
+	# This function calls _readtree_wait as a callback.
+	#
+	# _readtree_wait in turn either calls _do_clone_submodules directly,
+	# or calls _postcheckout_wait as a callback which then calls
+	# _do_clone_submodules.
+	#
+	# _do_clone_submodules calls _do_validate_submodule_cloning.
+	#
+	# _do_validate_submodule_cloning stops the status operation.
+	#
+	# There are no other calls into this chain from other code.
+
+	set o_status_op [$status start \
 		[mc "Creating working directory"] \
-		[mc "files"]
+		[mc "files"]]
 
 	set readtree_err {}
 	set fd [git_read --stderr read-tree \
@@ -976,33 +989,9 @@ method _do_clone_checkout {HEAD} {
 	fileevent $fd readable [cb _readtree_wait $fd]
 }
 
-method _do_validate_submodule_cloning {ok} {
-	if {$ok} {
-		$o_cons done $ok
-		set done 1
-	} else {
-		_clone_failed $this [mc "Cannot clone submodules."]
-	}
-}
-
-method _do_clone_submodules {} {
-	if {$recursive eq {true}} {
-		destroy $w_body
-		set o_cons [console::embed \
-			$w_body \
-			[mc "Cloning submodules"]]
-		pack $w_body -fill both -expand 1 -padx 10
-		$o_cons exec \
-			[list git submodule update --init --recursive] \
-			[cb _do_validate_submodule_cloning]
-	} else {
-		set done 1
-	}
-}
-
 method _readtree_wait {fd} {
 	set buf [read $fd]
-	$o_cons update_meter $buf
+	$o_status_op update_meter $buf
 	append readtree_err $buf
 
 	fconfigure $fd -blocking 1
@@ -1050,6 +1039,34 @@ method _postcheckout_wait {fd_ph} {
 	fconfigure $fd_ph -blocking 0
 }
 
+method _do_clone_submodules {} {
+	if {$recursive eq {true}} {
+		$o_status_op stop
+		set o_status_op {}
+
+		destroy $w_body
+
+		set o_cons [console::embed \
+			$w_body \
+			[mc "Cloning submodules"]]
+		pack $w_body -fill both -expand 1 -padx 10
+		$o_cons exec \
+			[list git submodule update --init --recursive] \
+			[cb _do_validate_submodule_cloning]
+	} else {
+		set done 1
+	}
+}
+
+method _do_validate_submodule_cloning {ok} {
+	if {$ok} {
+		$o_cons done $ok
+		set done 1
+	} else {
+		_clone_failed $this [mc "Cannot clone submodules."]
+	}
+}
+
 ######################################################################
 ##
 ## Open Existing Repository