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

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

1 files changed, 836 insertions, 0 deletions

diff --git a/third_party/git/git-gui/lib/diff.tcl b/third_party/git/git-gui/lib/diff.tcl
new file mode 100644
index 000000000000..68c4a6c7366f
--- /dev/null
+++ b/third_party/git/git-gui/lib/diff.tcl
@@ -0,0 +1,836 @@
+# git-gui diff viewer
+# Copyright (C) 2006, 2007 Shawn Pearce
+
+proc apply_tab_size {{firsttab {}}} {
+	global have_tk85 repo_config ui_diff
+
+	set w [font measure font_diff "0"]
+	if {$have_tk85 && $firsttab != 0} {
+		$ui_diff configure -tabs [list [expr {$firsttab * $w}] [expr {($firsttab + $repo_config(gui.tabsize)) * $w}]]
+	} elseif {$have_tk85 || $repo_config(gui.tabsize) != 8} {
+		$ui_diff configure -tabs [expr {$repo_config(gui.tabsize) * $w}]
+	} else {
+		$ui_diff configure -tabs {}
+	}
+}
+
+proc clear_diff {} {
+	global ui_diff current_diff_path current_diff_header
+	global ui_index ui_workdir
+
+	$ui_diff conf -state normal
+	$ui_diff delete 0.0 end
+	$ui_diff conf -state disabled
+
+	set current_diff_path {}
+	set current_diff_header {}
+
+	$ui_index tag remove in_diff 0.0 end
+	$ui_workdir tag remove in_diff 0.0 end
+}
+
+proc reshow_diff {{after {}}} {
+	global file_states file_lists
+	global current_diff_path current_diff_side
+	global ui_diff
+
+	set p $current_diff_path
+	if {$p eq {}} {
+		# No diff is being shown.
+	} elseif {$current_diff_side eq {}} {
+		clear_diff
+	} elseif {[catch {set s $file_states($p)}]
+		|| [lsearch -sorted -exact $file_lists($current_diff_side) $p] == -1} {
+
+		if {[find_next_diff $current_diff_side $p {} {[^O]}]} {
+			next_diff $after
+		} else {
+			clear_diff
+		}
+	} else {
+		set save_pos [lindex [$ui_diff yview] 0]
+		show_diff $p $current_diff_side {} $save_pos $after
+	}
+}
+
+proc force_diff_encoding {enc} {
+	global current_diff_path
+	
+	if {$current_diff_path ne {}} {
+		force_path_encoding $current_diff_path $enc
+		reshow_diff
+	}
+}
+
+proc handle_empty_diff {} {
+	global current_diff_path file_states file_lists
+	global diff_empty_count
+
+	set path $current_diff_path
+	set s $file_states($path)
+	if {[lindex $s 0] ne {_M} || [has_textconv $path]} return
+
+	# Prevent infinite rescan loops
+	incr diff_empty_count
+	if {$diff_empty_count > 1} return
+
+	info_popup [mc "No differences detected.
+
+%s has no changes.
+
+The modification date of this file was updated by another application, but the content within the file was not changed.
+
+A rescan will be automatically started to find other files which may have the same state." [short_path $path]]
+
+	clear_diff
+	display_file $path __
+	rescan ui_ready 0
+}
+
+proc show_diff {path w {lno {}} {scroll_pos {}} {callback {}}} {
+	global file_states file_lists
+	global is_3way_diff is_conflict_diff diff_active repo_config
+	global ui_diff ui_index ui_workdir
+	global current_diff_path current_diff_side current_diff_header
+	global current_diff_queue
+
+	if {$diff_active || ![lock_index read]} return
+
+	clear_diff
+	if {$lno == {}} {
+		set lno [lsearch -sorted -exact $file_lists($w) $path]
+		if {$lno >= 0} {
+			incr lno
+		}
+	}
+	if {$lno >= 1} {
+		$w tag add in_diff $lno.0 [expr {$lno + 1}].0
+		$w see $lno.0
+	}
+
+	set s $file_states($path)
+	set m [lindex $s 0]
+	set is_conflict_diff 0
+	set current_diff_path $path
+	set current_diff_side $w
+	set current_diff_queue {}
+	ui_status [mc "Loading diff of %s..." [escape_path $path]]
+
+	set cont_info [list $scroll_pos $callback]
+
+	apply_tab_size 0
+
+	if {[string first {U} $m] >= 0} {
+		merge_load_stages $path [list show_unmerged_diff $cont_info]
+	} elseif {$m eq {_O}} {
+		show_other_diff $path $w $m $cont_info
+	} else {
+		start_show_diff $cont_info
+	}
+
+	global current_diff_path selected_paths
+	set selected_paths($current_diff_path) 1
+}
+
+proc show_unmerged_diff {cont_info} {
+	global current_diff_path current_diff_side
+	global merge_stages ui_diff is_conflict_diff
+	global current_diff_queue
+
+	if {$merge_stages(2) eq {}} {
+		set is_conflict_diff 1
+		lappend current_diff_queue \
+			[list [mc "LOCAL: deleted\nREMOTE:\n"] d= \
+			    [list ":1:$current_diff_path" ":3:$current_diff_path"]]
+	} elseif {$merge_stages(3) eq {}} {
+		set is_conflict_diff 1
+		lappend current_diff_queue \
+			[list [mc "REMOTE: deleted\nLOCAL:\n"] d= \
+			    [list ":1:$current_diff_path" ":2:$current_diff_path"]]
+	} elseif {[lindex $merge_stages(1) 0] eq {120000}
+		|| [lindex $merge_stages(2) 0] eq {120000}
+		|| [lindex $merge_stages(3) 0] eq {120000}} {
+		set is_conflict_diff 1
+		lappend current_diff_queue \
+			[list [mc "LOCAL:\n"] d= \
+			    [list ":1:$current_diff_path" ":2:$current_diff_path"]]
+		lappend current_diff_queue \
+			[list [mc "REMOTE:\n"] d= \
+			    [list ":1:$current_diff_path" ":3:$current_diff_path"]]
+	} else {
+		start_show_diff $cont_info
+		return
+	}
+
+	advance_diff_queue $cont_info
+}
+
+proc advance_diff_queue {cont_info} {
+	global current_diff_queue ui_diff
+
+	set item [lindex $current_diff_queue 0]
+	set current_diff_queue [lrange $current_diff_queue 1 end]
+
+	$ui_diff conf -state normal
+	$ui_diff insert end [lindex $item 0] [lindex $item 1]
+	$ui_diff conf -state disabled
+
+	start_show_diff $cont_info [lindex $item 2]
+}
+
+proc show_other_diff {path w m cont_info} {
+	global file_states file_lists
+	global is_3way_diff diff_active repo_config
+	global ui_diff ui_index ui_workdir
+	global current_diff_path current_diff_side current_diff_header
+
+	# - Git won't give us the diff, there's nothing to compare to!
+	#
+	if {$m eq {_O}} {
+		set max_sz 100000
+		set type unknown
+		if {[catch {
+				set type [file type $path]
+				switch -- $type {
+				directory {
+					set type submodule
+					set content {}
+					set sz 0
+				}
+				link {
+					set content [file readlink $path]
+					set sz [string length $content]
+				}
+				file {
+					set fd [open $path r]
+					fconfigure $fd \
+						-eofchar {} \
+						-encoding [get_path_encoding $path]
+					set content [read $fd $max_sz]
+					close $fd
+					set sz [file size $path]
+				}
+				default {
+					error "'$type' not supported"
+				}
+				}
+			} err ]} {
+			set diff_active 0
+			unlock_index
+			ui_status [mc "Unable to display %s" [escape_path $path]]
+			error_popup [strcat [mc "Error loading file:"] "\n\n$err"]
+			return
+		}
+		$ui_diff conf -state normal
+		if {$type eq {submodule}} {
+			$ui_diff insert end \
+				"* [mc "Git Repository (subproject)"]\n" \
+				d_info
+		} elseif {![catch {set type [exec file $path]}]} {
+			set n [string length $path]
+			if {[string equal -length $n $path $type]} {
+				set type [string range $type $n end]
+				regsub {^:?\s*} $type {} type
+			}
+			$ui_diff insert end "* $type\n" d_info
+		}
+		if {[string first "\0" $content] != -1} {
+			$ui_diff insert end \
+				[mc "* Binary file (not showing content)."] \
+				d_info
+		} else {
+			if {$sz > $max_sz} {
+				$ui_diff insert end [mc \
+"* Untracked file is %d bytes.
+* Showing only first %d bytes.
+" $sz $max_sz] d_info
+			}
+			$ui_diff insert end $content
+			if {$sz > $max_sz} {
+				$ui_diff insert end [mc "
+* Untracked file clipped here by %s.
+* To see the entire file, use an external editor.
+" [appname]] d_info
+			}
+		}
+		$ui_diff conf -state disabled
+		set diff_active 0
+		unlock_index
+		set scroll_pos [lindex $cont_info 0]
+		if {$scroll_pos ne {}} {
+			update
+			$ui_diff yview moveto $scroll_pos
+		}
+		ui_ready
+		set callback [lindex $cont_info 1]
+		if {$callback ne {}} {
+			eval $callback
+		}
+		return
+	}
+}
+
+proc get_conflict_marker_size {path} {
+	set size 7
+	catch {
+		set fd_rc [eval [list git_read check-attr "conflict-marker-size" -- $path]]
+		set ret [gets $fd_rc line]
+		close $fd_rc
+		if {$ret > 0} {
+			regexp {.*: conflict-marker-size: (\d+)$} $line line size
+		}
+	}
+	return $size
+}
+
+proc start_show_diff {cont_info {add_opts {}}} {
+	global file_states file_lists
+	global is_3way_diff is_submodule_diff diff_active repo_config
+	global ui_diff ui_index ui_workdir
+	global current_diff_path current_diff_side current_diff_header
+
+	set path $current_diff_path
+	set w $current_diff_side
+
+	set s $file_states($path)
+	set m [lindex $s 0]
+	set is_3way_diff 0
+	set is_submodule_diff 0
+	set diff_active 1
+	set current_diff_header {}
+	set conflict_size [get_conflict_marker_size $path]
+
+	set cmd [list]
+	if {$w eq $ui_index} {
+		lappend cmd diff-index
+		lappend cmd --cached
+		if {[git-version >= "1.7.2"]} {
+			lappend cmd --ignore-submodules=dirty
+		}
+	} elseif {$w eq $ui_workdir} {
+		if {[string first {U} $m] >= 0} {
+			lappend cmd diff
+		} else {
+			lappend cmd diff-files
+		}
+	}
+	if {![is_config_false gui.textconv] && [git-version >= 1.6.1]} {
+		lappend cmd --textconv
+	}
+
+	if {[string match {160000 *} [lindex $s 2]]
+	 || [string match {160000 *} [lindex $s 3]]} {
+		set is_submodule_diff 1
+
+		if {[git-version >= "1.6.6"]} {
+			lappend cmd --submodule
+		}
+	}
+
+	lappend cmd -p
+	lappend cmd --color
+	set cmd [concat $cmd $repo_config(gui.diffopts)]
+	if {$repo_config(gui.diffcontext) >= 1} {
+		lappend cmd "-U$repo_config(gui.diffcontext)"
+	}
+	if {$w eq $ui_index} {
+		lappend cmd [PARENT]
+	}
+	if {$add_opts ne {}} {
+		eval lappend cmd $add_opts
+	} else {
+		lappend cmd --
+		lappend cmd $path
+	}
+
+	if {$is_submodule_diff && [git-version < "1.6.6"]} {
+		if {$w eq $ui_index} {
+			set cmd [list submodule summary --cached -- $path]
+		} else {
+			set cmd [list submodule summary --files -- $path]
+		}
+	}
+
+	if {[catch {set fd [eval git_read --nice $cmd]} err]} {
+		set diff_active 0
+		unlock_index
+		ui_status [mc "Unable to display %s" [escape_path $path]]
+		error_popup [strcat [mc "Error loading diff:"] "\n\n$err"]
+		return
+	}
+
+	set ::current_diff_inheader 1
+	fconfigure $fd \
+		-blocking 0 \
+		-encoding [get_path_encoding $path] \
+		-translation lf
+	fileevent $fd readable [list read_diff $fd $conflict_size $cont_info]
+}
+
+proc parse_color_line {line} {
+	set start 0
+	set result ""
+	set markup [list]
+	set regexp {\033\[((?:\d+;)*\d+)?m}
+	set need_reset 0
+	while {[regexp -indices -start $start $regexp $line match code]} {
+		foreach {begin end} $match break
+		append result [string range $line $start [expr {$begin - 1}]]
+		set pos [string length $result]
+		set col [eval [linsert $code 0 string range $line]]
+		set start [incr end]
+		if {$col eq "0" || $col eq ""} {
+			if {!$need_reset} continue
+			set need_reset 0
+		} else {
+			set need_reset 1
+		}
+		lappend markup $pos $col
+	}
+	append result [string range $line $start end]
+	if {[llength $markup] < 4} {set markup {}}
+	return [list $result $markup]
+}
+
+proc read_diff {fd conflict_size cont_info} {
+	global ui_diff diff_active is_submodule_diff
+	global is_3way_diff is_conflict_diff current_diff_header
+	global current_diff_queue
+	global diff_empty_count
+
+	$ui_diff conf -state normal
+	while {[gets $fd line] >= 0} {
+		foreach {line markup} [parse_color_line $line] break
+		set line [string map {\033 ^} $line]
+
+		set tags {}
+
+		# -- Check for start of diff header.
+		if {   [string match {diff --git *}      $line]
+		    || [string match {diff --cc *}       $line]
+		    || [string match {diff --combined *} $line]} {
+			set ::current_diff_inheader 1
+		}
+
+		# -- Check for end of diff header (any hunk line will do this).
+		#
+		if {[regexp {^@@+ } $line]} {set ::current_diff_inheader 0}
+
+		# -- Automatically detect if this is a 3 way diff.
+		#
+		if {[string match {@@@ *} $line]} {
+			set is_3way_diff 1
+			apply_tab_size 1
+		}
+
+		if {$::current_diff_inheader} {
+
+			# -- These two lines stop a diff header and shouldn't be in there
+			if {   [string match {Binary files * and * differ} $line]
+			    || [regexp {^\* Unmerged path }                $line]} {
+				set ::current_diff_inheader 0
+			} else {
+				append current_diff_header $line "\n"
+			}
+
+			# -- Cleanup uninteresting diff header lines.
+			#
+			if {   [string match {diff --git *}      $line]
+			    || [string match {diff --cc *}       $line]
+			    || [string match {diff --combined *} $line]
+			    || [string match {--- *}             $line]
+			    || [string match {+++ *}             $line]
+			    || [string match {index *}           $line]} {
+				continue
+			}
+
+			# -- Name it symlink, not 120000
+			#    Note, that the original line is in $current_diff_header
+			regsub {^(deleted|new) file mode 120000} $line {\1 symlink} line
+
+		} elseif {   $line eq {\ No newline at end of file}} {
+			# -- Handle some special lines
+		} elseif {$is_3way_diff} {
+			set op [string range $line 0 1]
+			switch -- $op {
+			{  } {set tags {}}
+			{@@} {set tags d_@}
+			{ +} {set tags d_s+}
+			{ -} {set tags d_s-}
+			{+ } {set tags d_+s}
+			{- } {set tags d_-s}
+			{--} {set tags d_--}
+			{++} {
+				set regexp [string map [list %conflict_size $conflict_size]\
+								{^\+\+([<>=]){%conflict_size}(?: |$)}]
+				if {[regexp $regexp $line _g op]} {
+					set is_conflict_diff 1
+					set line [string replace $line 0 1 {  }]
+					set tags d$op
+				} else {
+					set tags d_++
+				}
+			}
+			default {
+				puts "error: Unhandled 3 way diff marker: {$op}"
+				set tags {}
+			}
+			}
+		} elseif {$is_submodule_diff} {
+			if {$line == ""} continue
+			if {[regexp {^Submodule } $line]} {
+				set tags d_info
+			} elseif {[regexp {^\* } $line]} {
+				set line [string replace $line 0 1 {Submodule }]
+				set tags d_info
+			} else {
+				set op [string range $line 0 2]
+				switch -- $op {
+				{  <} {set tags d_-}
+				{  >} {set tags d_+}
+				{  W} {set tags {}}
+				default {
+					puts "error: Unhandled submodule diff marker: {$op}"
+					set tags {}
+				}
+				}
+			}
+		} else {
+			set op [string index $line 0]
+			switch -- $op {
+			{ } {set tags {}}
+			{@} {set tags d_@}
+			{-} {set tags d_-}
+			{+} {
+				set regexp [string map [list %conflict_size $conflict_size]\
+								{^\+([<>=]){%conflict_size}(?: |$)}]
+				if {[regexp $regexp $line _g op]} {
+					set is_conflict_diff 1
+					set tags d$op
+				} else {
+					set tags d_+
+				}
+			}
+			default {
+				puts "error: Unhandled 2 way diff marker: {$op}"
+				set tags {}
+			}
+			}
+		}
+		set mark [$ui_diff index "end - 1 line linestart"]
+		$ui_diff insert end $line $tags
+		if {[string index $line end] eq "\r"} {
+			$ui_diff tag add d_cr {end - 2c}
+		}
+		$ui_diff insert end "\n" $tags
+
+		foreach {posbegin colbegin posend colend} $markup {
+			set prefix clr
+			foreach style [lsort -integer [split $colbegin ";"]] {
+				if {$style eq "7"} {append prefix i; continue}
+				if {$style != 4 && ($style < 30 || $style > 47)} {continue}
+				set a "$mark linestart + $posbegin chars"
+				set b "$mark linestart + $posend chars"
+				catch {$ui_diff tag add $prefix$style $a $b}
+			}
+		}
+	}
+	$ui_diff conf -state disabled
+
+	if {[eof $fd]} {
+		close $fd
+
+		if {$current_diff_queue ne {}} {
+			advance_diff_queue $cont_info
+			return
+		}
+
+		set diff_active 0
+		unlock_index
+		set scroll_pos [lindex $cont_info 0]
+		if {$scroll_pos ne {}} {
+			update
+			$ui_diff yview moveto $scroll_pos
+		}
+		ui_ready
+
+		if {[$ui_diff index end] eq {2.0}} {
+			handle_empty_diff
+		} else {
+			set diff_empty_count 0
+		}
+
+		set callback [lindex $cont_info 1]
+		if {$callback ne {}} {
+			eval $callback
+		}
+	}
+}
+
+proc apply_hunk {x y} {
+	global current_diff_path current_diff_header current_diff_side
+	global ui_diff ui_index file_states
+
+	if {$current_diff_path eq {} || $current_diff_header eq {}} return
+	if {![lock_index apply_hunk]} return
+
+	set apply_cmd {apply --cached --whitespace=nowarn}
+	set mi [lindex $file_states($current_diff_path) 0]
+	if {$current_diff_side eq $ui_index} {
+		set failed_msg [mc "Failed to unstage selected hunk."]
+		lappend apply_cmd --reverse
+		if {[string index $mi 0] ne {M}} {
+			unlock_index
+			return
+		}
+	} else {
+		set failed_msg [mc "Failed to stage selected hunk."]
+		if {[string index $mi 1] ne {M}} {
+			unlock_index
+			return
+		}
+	}
+
+	set s_lno [lindex [split [$ui_diff index @$x,$y] .] 0]
+	set s_lno [$ui_diff search -backwards -regexp ^@@ $s_lno.0 0.0]
+	if {$s_lno eq {}} {
+		unlock_index
+		return
+	}
+
+	set e_lno [$ui_diff search -forwards -regexp ^@@ "$s_lno + 1 lines" end]
+	if {$e_lno eq {}} {
+		set e_lno end
+	}
+
+	if {[catch {
+		set enc [get_path_encoding $current_diff_path]
+		set p [eval git_write $apply_cmd]
+		fconfigure $p -translation binary -encoding $enc
+		puts -nonewline $p $current_diff_header
+		puts -nonewline $p [$ui_diff get $s_lno $e_lno]
+		close $p} err]} {
+		error_popup "$failed_msg\n\n$err"
+		unlock_index
+		return
+	}
+
+	$ui_diff conf -state normal
+	$ui_diff delete $s_lno $e_lno
+	$ui_diff conf -state disabled
+
+	if {[$ui_diff get 1.0 end] eq "\n"} {
+		set o _
+	} else {
+		set o ?
+	}
+
+	if {$current_diff_side eq $ui_index} {
+		set mi ${o}M
+	} elseif {[string index $mi 0] eq {_}} {
+		set mi M$o
+	} else {
+		set mi ?$o
+	}
+	unlock_index
+	display_file $current_diff_path $mi
+	# This should trigger shift to the next changed file
+	if {$o eq {_}} {
+		reshow_diff
+	}
+}
+
+proc apply_range_or_line {x y} {
+	global current_diff_path current_diff_header current_diff_side
+	global ui_diff ui_index file_states
+
+	set selected [$ui_diff tag nextrange sel 0.0]
+
+	if {$selected == {}} {
+		set first [$ui_diff index "@$x,$y"]
+		set last $first
+	} else {
+		set first [lindex $selected 0]
+		set last [lindex $selected 1]
+	}
+
+	set first_l [$ui_diff index "$first linestart"]
+	set last_l [$ui_diff index "$last lineend"]
+
+	if {$current_diff_path eq {} || $current_diff_header eq {}} return
+	if {![lock_index apply_hunk]} return
+
+	set apply_cmd {apply --cached --whitespace=nowarn}
+	set mi [lindex $file_states($current_diff_path) 0]
+	if {$current_diff_side eq $ui_index} {
+		set failed_msg [mc "Failed to unstage selected line."]
+		set to_context {+}
+		lappend apply_cmd --reverse
+		if {[string index $mi 0] ne {M}} {
+			unlock_index
+			return
+		}
+	} else {
+		set failed_msg [mc "Failed to stage selected line."]
+		set to_context {-}
+		if {[string index $mi 1] ne {M}} {
+			unlock_index
+			return
+		}
+	}
+
+	set wholepatch {}
+
+	while {$first_l < $last_l} {
+		set i_l [$ui_diff search -backwards -regexp ^@@ $first_l 0.0]
+		if {$i_l eq {}} {
+			# If there's not a @@ above, then the selected range
+			# must have come before the first_l @@
+			set i_l [$ui_diff search -regexp ^@@ $first_l $last_l]
+		}
+		if {$i_l eq {}} {
+			unlock_index
+			return
+		}
+		# $i_l is now at the beginning of a line
+
+		# pick start line number from hunk header
+		set hh [$ui_diff get $i_l "$i_l + 1 lines"]
+		set hh [lindex [split $hh ,] 0]
+		set hln [lindex [split $hh -] 1]
+		set hln [lindex [split $hln " "] 0]
+
+		# There is a special situation to take care of. Consider this
+		# hunk:
+		#
+		#    @@ -10,4 +10,4 @@
+		#     context before
+		#    -old 1
+		#    -old 2
+		#    +new 1
+		#    +new 2
+		#     context after
+		#
+		# We used to keep the context lines in the order they appear in
+		# the hunk. But then it is not possible to correctly stage only
+		# "-old 1" and "+new 1" - it would result in this staged text:
+		#
+		#    context before
+		#    old 2
+		#    new 1
+		#    context after
+		#
+		# (By symmetry it is not possible to *un*stage "old 2" and "new
+		# 2".)
+		#
+		# We resolve the problem by introducing an asymmetry, namely,
+		# when a "+" line is *staged*, it is moved in front of the
+		# context lines that are generated from the "-" lines that are
+		# immediately before the "+" block. That is, we construct this
+		# patch:
+		#
+		#    @@ -10,4 +10,5 @@
+		#     context before
+		#    +new 1
+		#     old 1
+		#     old 2
+		#     context after
+		#
+		# But we do *not* treat "-" lines that are *un*staged in a
+		# special way.
+		#
+		# With this asymmetry it is possible to stage the change "old
+		# 1" -> "new 1" directly, and to stage the change "old 2" ->
+		# "new 2" by first staging the entire hunk and then unstaging
+		# the change "old 1" -> "new 1".
+		#
+		# Applying multiple lines adds complexity to the special
+		# situation.  The pre_context must be moved after the entire
+		# first block of consecutive staged "+" lines, so that
+		# staging both additions gives the following patch:
+		#
+		#    @@ -10,4 +10,6 @@
+		#     context before
+		#    +new 1
+		#    +new 2
+		#     old 1
+		#     old 2
+		#     context after
+
+		# This is non-empty if and only if we are _staging_ changes;
+		# then it accumulates the consecutive "-" lines (after
+		# converting them to context lines) in order to be moved after
+		# "+" change lines.
+		set pre_context {}
+
+		set n 0
+		set m 0
+		set i_l [$ui_diff index "$i_l + 1 lines"]
+		set patch {}
+		while {[$ui_diff compare $i_l < "end - 1 chars"] &&
+		       [$ui_diff get $i_l "$i_l + 2 chars"] ne {@@}} {
+			set next_l [$ui_diff index "$i_l + 1 lines"]
+			set c1 [$ui_diff get $i_l]
+			if {[$ui_diff compare $first_l <= $i_l] &&
+			    [$ui_diff compare $i_l < $last_l] &&
+			    ($c1 eq {-} || $c1 eq {+})} {
+				# a line to stage/unstage
+				set ln [$ui_diff get $i_l $next_l]
+				if {$c1 eq {-}} {
+					set n [expr $n+1]
+					set patch "$patch$pre_context$ln"
+					set pre_context {}
+				} else {
+					set m [expr $m+1]
+					set patch "$patch$ln"
+				}
+			} elseif {$c1 ne {-} && $c1 ne {+}} {
+				# context line
+				set ln [$ui_diff get $i_l $next_l]
+				set patch "$patch$pre_context$ln"
+				# Skip the "\ No newline at end of
+				# file". Depending on the locale setting
+				# we don't know what this line looks
+				# like exactly. The only thing we do
+				# know is that it starts with "\ "
+				if {![string match {\\ *} $ln]} {
+					set n [expr $n+1]
+					set m [expr $m+1]
+				}
+				set pre_context {}
+			} elseif {$c1 eq $to_context} {
+				# turn change line into context line
+				set ln [$ui_diff get "$i_l + 1 chars" $next_l]
+				if {$c1 eq {-}} {
+					set pre_context "$pre_context $ln"
+				} else {
+					set patch "$patch $ln"
+				}
+				set n [expr $n+1]
+				set m [expr $m+1]
+			} else {
+				# a change in the opposite direction of
+				# to_context which is outside the range of
+				# lines to apply.
+				set patch "$patch$pre_context"
+				set pre_context {}
+			}
+			set i_l $next_l
+		}
+		set patch "$patch$pre_context"
+		set wholepatch "$wholepatch@@ -$hln,$n +$hln,$m @@\n$patch"
+		set first_l [$ui_diff index "$next_l + 1 lines"]
+	}
+
+	if {[catch {
+		set enc [get_path_encoding $current_diff_path]
+		set p [eval git_write $apply_cmd]
+		fconfigure $p -translation binary -encoding $enc
+		puts -nonewline $p $current_diff_header
+		puts -nonewline $p $wholepatch
+		close $p} err]} {
+		error_popup "$failed_msg\n\n$err"
+	}
+
+	unlock_index
+}