Merge git-gui

This merges git-gui project of Shawn as a subproject of git.git
at git-gui/ subdirectory.

This merge only melds two histories together.  The toplevel Makefile
does not even know about git-gui yet.

Signed-off-by: Junio C Hamano <junkio@cox.net>

5 files changed, 6065 insertions, 0 deletions

diff --git a/git-gui/.gitignore b/git-gui/.gitignore
new file mode 100644
index 0000000000..c714d382e8
--- /dev/null
+++ b/git-gui/.gitignore
@@ -0,0 +1,3 @@
+GIT-VERSION-FILE
+git-citool
+git-gui
diff --git a/git-gui/GIT-VERSION-GEN b/git-gui/GIT-VERSION-GEN
new file mode 100755
index 0000000000..79f1c527ff
--- /dev/null
+++ b/git-gui/GIT-VERSION-GEN
@@ -0,0 +1,46 @@
+#!/bin/sh
+
+GVF=GIT-VERSION-FILE
+DEF_VER=v0.5.GIT
+
+LF='
+'
+
+# First try git-describe, then see if there is a version file
+# (included in release tarballs), then default
+if VN=$(git describe --abbrev=4 HEAD 2>/dev/null) &&
+   case "$VN" in
+   *$LF*) (exit 1) ;;
+   v[0-9]*) : happy ;;
+   esac
+then
+	VN=$(echo "$VN" | sed -e 's/-/./g');
+elif test -f version
+then
+	VN=$(cat version) || VN="$DEF_VER"
+else
+	VN="$DEF_VER"
+fi
+
+VN=$(expr "$VN" : v*'\(.*\)')
+
+dirty=$(sh -c 'git diff-index --name-only HEAD' 2>/dev/null) || dirty=
+case "$dirty" in
+'')
+	;;
+*)
+	VN="$VN-dirty" ;;
+esac
+
+if test -r $GVF
+then
+	VC=$(sed -e 's/^GIT_VERSION = //' <$GVF)
+else
+	VC=unset
+fi
+test "$VN" = "$VC" || {
+	echo >&2 "GIT_VERSION = $VN"
+	echo "GIT_VERSION = $VN" >$GVF
+}
+
+
diff --git a/git-gui/Makefile b/git-gui/Makefile
new file mode 100644
index 0000000000..8fade69127
--- /dev/null
+++ b/git-gui/Makefile
@@ -0,0 +1,48 @@
+all::
+
+GIT-VERSION-FILE: .FORCE-GIT-VERSION-FILE
+	@$(SHELL_PATH) ./GIT-VERSION-GEN
+-include GIT-VERSION-FILE
+
+SCRIPT_SH = git-gui.sh
+GITGUI_BUILT_INS = git-citool
+ALL_PROGRAMS = $(GITGUI_BUILT_INS) $(patsubst %.sh,%,$(SCRIPT_SH))
+
+ifndef SHELL_PATH
+	SHELL_PATH = /bin/sh
+endif
+
+gitexecdir := $(shell git --exec-path)
+INSTALL = install
+
+DESTDIR_SQ = $(subst ','\'',$(DESTDIR))
+gitexecdir_SQ = $(subst ','\'',$(gitexecdir))
+
+SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH))
+
+$(patsubst %.sh,%,$(SCRIPT_SH)) : % : %.sh
+	rm -f $@ $@+
+	sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \
+		-e 's/@@GIT_VERSION@@/$(GIT_VERSION)/g' \
+		$@.sh >$@+
+	chmod +x $@+
+	mv $@+ $@
+
+$(GITGUI_BUILT_INS): git-gui
+	rm -f $@ && ln git-gui $@
+
+# These can record GIT_VERSION
+$(patsubst %.sh,%,$(SCRIPT_SH)): GIT-VERSION-FILE
+
+all:: $(ALL_PROGRAMS)
+
+install: all
+	$(INSTALL) -d -m755 '$(DESTDIR_SQ)$(gitexecdir_SQ)'
+	$(INSTALL) git-gui '$(DESTDIR_SQ)$(gitexecdir_SQ)'
+	$(foreach p,$(GITGUI_BUILT_INS), rm -f '$(DESTDIR_SQ)$(gitexecdir_SQ)/$p' && ln '$(DESTDIR_SQ)$(gitexecdir_SQ)/git-gui' '$(DESTDIR_SQ)$(gitexecdir_SQ)/$p' ;)
+
+clean::
+	rm -f $(ALL_PROGRAMS) GIT-VERSION-FILE
+
+.PHONY: all install clean
+.PHONY: .FORCE-GIT-VERSION-FILE
diff --git a/git-gui/TODO b/git-gui/TODO
new file mode 100644
index 0000000000..b95a137322
--- /dev/null
+++ b/git-gui/TODO
@@ -0,0 +1,44 @@
+Items outstanding:
+
+ * Add file to .gitignore or info/excludes.
+
+ * Populate the pull menu with local branches.
+
+ * Make use of the new default merge data stored in repo-config.
+
+ * Checkout a different local branch.
+
+ * Push any local branch to a remote branch.
+
+ * Merge any local branches through a real merge UI.
+
+ * Allow user to define keyboard shortcuts for frequently used fetch
+   or merge operations.  Or maybe just define a keyboard shortcut
+   for default fetch/default merge of current branch is enough;
+   but I do know a few users who merge a couple of common branches
+   also into the same branch so one default isn't quite enough.
+
+ * Better organize fetch/push/pull console windows.
+
+ * Clone UI (to download a new repository).
+
+ * Remotes editor (for .git/config format only).
+
+ * Show a shortlog of the last couple of commits in the main window,
+   to give the user warm fuzzy feelings that we have their data
+   saved.  Actually this may be the set of commits not yet in
+   the upstream (aka default merge branch remote repository).
+
+ * GUI configuration editor for options listed in
+   git.git/Documentation/config.txt.  Ideally this would
+   parse that file and generate the options dialog from
+   the documentation itself, and include the help text
+   from the documentation as part of the UI somehow.
+
+Known bugs:
+
+ * git-gui sometimes just closes on Windows with no error message.
+   I'm not sure what the problem is here.  I suspect the wish
+   process is just terminating due to a segfault or something,
+   as the do_quit proc in git-gui doesn't run.  It often seems to
+   occur while writing a commit message in the buffer.  Odd.
diff --git a/git-gui/git-gui.sh b/git-gui/git-gui.sh
new file mode 100755
index 0000000000..ea16be43ac
--- /dev/null
+++ b/git-gui/git-gui.sh
@@ -0,0 +1,5924 @@
+#!/bin/sh
+# Tcl ignores the next line -*- tcl -*- \
+exec wish "$0" -- "$@"
+
+set appvers {@@GIT_VERSION@@}
+set copyright {
+Copyright © 2006, 2007 Shawn Pearce, Paul Mackerras.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA}
+
+######################################################################
+##
+## read only globals
+
+set _appname [lindex [file split $argv0] end]
+set _gitdir {}
+set _gitexec {}
+set _reponame {}
+set _iscygwin {}
+
+proc appname {} {
+	global _appname
+	return $_appname
+}
+
+proc gitdir {args} {
+	global _gitdir
+	if {$args eq {}} {
+		return $_gitdir
+	}
+	return [eval [concat [list file join $_gitdir] $args]]
+}
+
+proc gitexec {args} {
+	global _gitexec
+	if {$_gitexec eq {}} {
+		if {[catch {set _gitexec [exec git --exec-path]} err]} {
+			error "Git not installed?\n\n$err"
+		}
+	}
+	if {$args eq {}} {
+		return $_gitexec
+	}
+	return [eval [concat [list file join $_gitexec] $args]]
+}
+
+proc reponame {} {
+	global _reponame
+	return $_reponame
+}
+
+proc is_MacOSX {} {
+	global tcl_platform tk_library
+	if {[tk windowingsystem] eq {aqua}} {
+		return 1
+	}
+	return 0
+}
+
+proc is_Windows {} {
+	global tcl_platform
+	if {$tcl_platform(platform) eq {windows}} {
+		return 1
+	}
+	return 0
+}
+
+proc is_Cygwin {} {
+	global tcl_platform _iscygwin
+	if {$_iscygwin eq {}} {
+		if {$tcl_platform(platform) eq {windows}} {
+			if {[catch {set p [exec cygpath --windir]} err]} {
+				set _iscygwin 0
+			} else {
+				set _iscygwin 1
+			}
+		} else {
+			set _iscygwin 0
+		}
+	}
+	return $_iscygwin
+}
+
+proc is_enabled {option} {
+	global enabled_options
+	if {[catch {set on $enabled_options($option)}]} {return 0}
+	return $on
+}
+
+proc enable_option {option} {
+	global enabled_options
+	set enabled_options($option) 1
+}
+
+proc disable_option {option} {
+	global enabled_options
+	set enabled_options($option) 0
+}
+
+######################################################################
+##
+## config
+
+proc is_many_config {name} {
+	switch -glob -- $name {
+	remote.*.fetch -
+	remote.*.push
+		{return 1}
+	*
+		{return 0}
+	}
+}
+
+proc is_config_true {name} {
+	global repo_config
+	if {[catch {set v $repo_config($name)}]} {
+		return 0
+	} elseif {$v eq {true} || $v eq {1} || $v eq {yes}} {
+		return 1
+	} else {
+		return 0
+	}
+}
+
+proc load_config {include_global} {
+	global repo_config global_config default_config
+
+	array unset global_config
+	if {$include_global} {
+		catch {
+			set fd_rc [open "| git config --global --list" r]
+			while {[gets $fd_rc line] >= 0} {
+				if {[regexp {^([^=]+)=(.*)$} $line line name value]} {
+					if {[is_many_config $name]} {
+						lappend global_config($name) $value
+					} else {
+						set global_config($name) $value
+					}
+				}
+			}
+			close $fd_rc
+		}
+	}
+
+	array unset repo_config
+	catch {
+		set fd_rc [open "| git config --list" r]
+		while {[gets $fd_rc line] >= 0} {
+			if {[regexp {^([^=]+)=(.*)$} $line line name value]} {
+				if {[is_many_config $name]} {
+					lappend repo_config($name) $value
+				} else {
+					set repo_config($name) $value
+				}
+			}
+		}
+		close $fd_rc
+	}
+
+	foreach name [array names default_config] {
+		if {[catch {set v $global_config($name)}]} {
+			set global_config($name) $default_config($name)
+		}
+		if {[catch {set v $repo_config($name)}]} {
+			set repo_config($name) $default_config($name)
+		}
+	}
+}
+
+proc save_config {} {
+	global default_config font_descs
+	global repo_config global_config
+	global repo_config_new global_config_new
+
+	foreach option $font_descs {
+		set name [lindex $option 0]
+		set font [lindex $option 1]
+		font configure $font \
+			-family $global_config_new(gui.$font^^family) \
+			-size $global_config_new(gui.$font^^size)
+		font configure ${font}bold \
+			-family $global_config_new(gui.$font^^family) \
+			-size $global_config_new(gui.$font^^size)
+		set global_config_new(gui.$name) [font configure $font]
+		unset global_config_new(gui.$font^^family)
+		unset global_config_new(gui.$font^^size)
+	}
+
+	foreach name [array names default_config] {
+		set value $global_config_new($name)
+		if {$value ne $global_config($name)} {
+			if {$value eq $default_config($name)} {
+				catch {exec git config --global --unset $name}
+			} else {
+				regsub -all "\[{}\]" $value {"} value
+				exec git config --global $name $value
+			}
+			set global_config($name) $value
+			if {$value eq $repo_config($name)} {
+				catch {exec git config --unset $name}
+				set repo_config($name) $value
+			}
+		}
+	}
+
+	foreach name [array names default_config] {
+		set value $repo_config_new($name)
+		if {$value ne $repo_config($name)} {
+			if {$value eq $global_config($name)} {
+				catch {exec git config --unset $name}
+			} else {
+				regsub -all "\[{}\]" $value {"} value
+				exec git config $name $value
+			}
+			set repo_config($name) $value
+		}
+	}
+}
+
+proc error_popup {msg} {
+	set title [appname]
+	if {[reponame] ne {}} {
+		append title " ([reponame])"
+	}
+	set cmd [list tk_messageBox \
+		-icon error \
+		-type ok \
+		-title "$title: error" \
+		-message $msg]
+	if {[winfo ismapped .]} {
+		lappend cmd -parent .
+	}
+	eval $cmd
+}
+
+proc warn_popup {msg} {
+	set title [appname]
+	if {[reponame] ne {}} {
+		append title " ([reponame])"
+	}
+	set cmd [list tk_messageBox \
+		-icon warning \
+		-type ok \
+		-title "$title: warning" \
+		-message $msg]
+	if {[winfo ismapped .]} {
+		lappend cmd -parent .
+	}
+	eval $cmd
+}
+
+proc info_popup {msg {parent .}} {
+	set title [appname]
+	if {[reponame] ne {}} {
+		append title " ([reponame])"
+	}
+	tk_messageBox \
+		-parent $parent \
+		-icon info \
+		-type ok \
+		-title $title \
+		-message $msg
+}
+
+proc ask_popup {msg} {
+	set title [appname]
+	if {[reponame] ne {}} {
+		append title " ([reponame])"
+	}
+	return [tk_messageBox \
+		-parent . \
+		-icon question \
+		-type yesno \
+		-title $title \
+		-message $msg]
+}
+
+######################################################################
+##
+## repository setup
+
+if {   [catch {set _gitdir $env(GIT_DIR)}]
+	&& [catch {set _gitdir [exec git rev-parse --git-dir]} err]} {
+	catch {wm withdraw .}
+	error_popup "Cannot find the git directory:\n\n$err"
+	exit 1
+}
+if {![file isdirectory $_gitdir] && [is_Cygwin]} {
+	catch {set _gitdir [exec cygpath --unix $_gitdir]}
+}
+if {![file isdirectory $_gitdir]} {
+	catch {wm withdraw .}
+	error_popup "Git directory not found:\n\n$_gitdir"
+	exit 1
+}
+if {[lindex [file split $_gitdir] end] ne {.git}} {
+	catch {wm withdraw .}
+	error_popup "Cannot use funny .git directory:\n\n$_gitdir"
+	exit 1
+}
+if {[catch {cd [file dirname $_gitdir]} err]} {
+	catch {wm withdraw .}
+	error_popup "No working directory [file dirname $_gitdir]:\n\n$err"
+	exit 1
+}
+set _reponame [lindex [file split \
+	[file normalize [file dirname $_gitdir]]] \
+	end]
+
+######################################################################
+##
+## task management
+
+set rescan_active 0
+set diff_active 0
+set last_clicked {}
+
+set disable_on_lock [list]
+set index_lock_type none
+
+proc lock_index {type} {
+	global index_lock_type disable_on_lock
+
+	if {$index_lock_type eq {none}} {
+		set index_lock_type $type
+		foreach w $disable_on_lock {
+			uplevel #0 $w disabled
+		}
+		return 1
+	} elseif {$index_lock_type eq "begin-$type"} {
+		set index_lock_type $type
+		return 1
+	}
+	return 0
+}
+
+proc unlock_index {} {
+	global index_lock_type disable_on_lock
+
+	set index_lock_type none
+	foreach w $disable_on_lock {
+		uplevel #0 $w normal
+	}
+}
+
+######################################################################
+##
+## status
+
+proc repository_state {ctvar hdvar mhvar} {
+	global current_branch
+	upvar $ctvar ct $hdvar hd $mhvar mh
+
+	set mh [list]
+
+	if {[catch {set current_branch [exec git symbolic-ref HEAD]}]} {
+		set current_branch {}
+	} else {
+		regsub ^refs/((heads|tags|remotes)/)? \
+			$current_branch \
+			{} \
+			current_branch
+	}
+
+	if {[catch {set hd [exec git rev-parse --verify HEAD]}]} {
+		set hd {}
+		set ct initial
+		return
+	}
+
+	set merge_head [gitdir MERGE_HEAD]
+	if {[file exists $merge_head]} {
+		set ct merge
+		set fd_mh [open $merge_head r]
+		while {[gets $fd_mh line] >= 0} {
+			lappend mh $line
+		}
+		close $fd_mh
+		return
+	}
+
+	set ct normal
+}
+
+proc PARENT {} {
+	global PARENT empty_tree
+
+	set p [lindex $PARENT 0]
+	if {$p ne {}} {
+		return $p
+	}
+	if {$empty_tree eq {}} {
+		set empty_tree [exec git mktree << {}]
+	}
+	return $empty_tree
+}
+
+proc rescan {after {honor_trustmtime 1}} {
+	global HEAD PARENT MERGE_HEAD commit_type
+	global ui_index ui_workdir ui_status_value ui_comm
+	global rescan_active file_states
+	global repo_config
+
+	if {$rescan_active > 0 || ![lock_index read]} return
+
+	repository_state newType newHEAD newMERGE_HEAD
+	if {[string match amend* $commit_type]
+		&& $newType eq {normal}
+		&& $newHEAD eq $HEAD} {
+	} else {
+		set HEAD $newHEAD
+		set PARENT $newHEAD
+		set MERGE_HEAD $newMERGE_HEAD
+		set commit_type $newType
+	}
+
+	array unset file_states
+
+	if {![$ui_comm edit modified]
+		|| [string trim [$ui_comm get 0.0 end]] eq {}} {
+		if {[load_message GITGUI_MSG]} {
+		} elseif {[load_message MERGE_MSG]} {
+		} elseif {[load_message SQUASH_MSG]} {
+		}
+		$ui_comm edit reset
+		$ui_comm edit modified false
+	}
+
+	if {[is_enabled branch]} {
+		load_all_heads
+		populate_branch_menu
+	}
+
+	if {$honor_trustmtime && $repo_config(gui.trustmtime) eq {true}} {
+		rescan_stage2 {} $after
+	} else {
+		set rescan_active 1
+		set ui_status_value {Refreshing file status...}
+		set cmd [list git update-index]
+		lappend cmd -q
+		lappend cmd --unmerged
+		lappend cmd --ignore-missing
+		lappend cmd --refresh
+		set fd_rf [open "| $cmd" r]
+		fconfigure $fd_rf -blocking 0 -translation binary
+		fileevent $fd_rf readable \
+			[list rescan_stage2 $fd_rf $after]
+	}
+}
+
+proc rescan_stage2 {fd after} {
+	global ui_status_value
+	global rescan_active buf_rdi buf_rdf buf_rlo
+
+	if {$fd ne {}} {
+		read $fd
+		if {![eof $fd]} return
+		close $fd
+	}
+
+	set ls_others [list | git ls-files --others -z \
+		--exclude-per-directory=.gitignore]
+	set info_exclude [gitdir info exclude]
+	if {[file readable $info_exclude]} {
+		lappend ls_others "--exclude-from=$info_exclude"
+	}
+
+	set buf_rdi {}
+	set buf_rdf {}
+	set buf_rlo {}
+
+	set rescan_active 3
+	set ui_status_value {Scanning for modified files ...}
+	set fd_di [open "| git diff-index --cached -z [PARENT]" r]
+	set fd_df [open "| git diff-files -z" r]
+	set fd_lo [open $ls_others r]
+
+	fconfigure $fd_di -blocking 0 -translation binary -encoding binary
+	fconfigure $fd_df -blocking 0 -translation binary -encoding binary
+	fconfigure $fd_lo -blocking 0 -translation binary -encoding binary
+	fileevent $fd_di readable [list read_diff_index $fd_di $after]
+	fileevent $fd_df readable [list read_diff_files $fd_df $after]
+	fileevent $fd_lo readable [list read_ls_others $fd_lo $after]
+}
+
+proc load_message {file} {
+	global ui_comm
+
+	set f [gitdir $file]
+	if {[file isfile $f]} {
+		if {[catch {set fd [open $f r]}]} {
+			return 0
+		}
+		set content [string trim [read $fd]]
+		close $fd
+		regsub -all -line {[ \r\t]+$} $content {} content
+		$ui_comm delete 0.0 end
+		$ui_comm insert end $content
+		return 1
+	}
+	return 0
+}
+
+proc read_diff_index {fd after} {
+	global buf_rdi
+
+	append buf_rdi [read $fd]
+	set c 0
+	set n [string length $buf_rdi]
+	while {$c < $n} {
+		set z1 [string first "\0" $buf_rdi $c]
+		if {$z1 == -1} break
+		incr z1
+		set z2 [string first "\0" $buf_rdi $z1]
+		if {$z2 == -1} break
+
+		incr c
+		set i [split [string range $buf_rdi $c [expr {$z1 - 2}]] { }]
+		set p [string range $buf_rdi $z1 [expr {$z2 - 1}]]
+		merge_state \
+			[encoding convertfrom $p] \
+			[lindex $i 4]? \
+			[list [lindex $i 0] [lindex $i 2]] \
+			[list]
+		set c $z2
+		incr c
+	}
+	if {$c < $n} {
+		set buf_rdi [string range $buf_rdi $c end]
+	} else {
+		set buf_rdi {}
+	}
+
+	rescan_done $fd buf_rdi $after
+}
+
+proc read_diff_files {fd after} {
+	global buf_rdf
+
+	append buf_rdf [read $fd]
+	set c 0
+	set n [string length $buf_rdf]
+	while {$c < $n} {
+		set z1 [string first "\0" $buf_rdf $c]
+		if {$z1 == -1} break
+		incr z1
+		set z2 [string first "\0" $buf_rdf $z1]
+		if {$z2 == -1} break
+
+		incr c
+		set i [split [string range $buf_rdf $c [expr {$z1 - 2}]] { }]
+		set p [string range $buf_rdf $z1 [expr {$z2 - 1}]]
+		merge_state \
+			[encoding convertfrom $p] \
+			?[lindex $i 4] \
+			[list] \
+			[list [lindex $i 0] [lindex $i 2]]
+		set c $z2
+		incr c
+	}
+	if {$c < $n} {
+		set buf_rdf [string range $buf_rdf $c end]
+	} else {
+		set buf_rdf {}
+	}
+
+	rescan_done $fd buf_rdf $after
+}
+
+proc read_ls_others {fd after} {
+	global buf_rlo
+
+	append buf_rlo [read $fd]
+	set pck [split $buf_rlo "\0"]
+	set buf_rlo [lindex $pck end]
+	foreach p [lrange $pck 0 end-1] {
+		merge_state [encoding convertfrom $p] ?O
+	}
+	rescan_done $fd buf_rlo $after
+}
+
+proc rescan_done {fd buf after} {
+	global rescan_active
+	global file_states repo_config
+	upvar $buf to_clear
+
+	if {![eof $fd]} return
+	set to_clear {}
+	close $fd
+	if {[incr rescan_active -1] > 0} return
+
+	prune_selection
+	unlock_index
+	display_all_files
+	reshow_diff
+	uplevel #0 $after
+}
+
+proc prune_selection {} {
+	global file_states selected_paths
+
+	foreach path [array names selected_paths] {
+		if {[catch {set still_here $file_states($path)}]} {
+			unset selected_paths($path)
+		}
+	}
+}
+
+######################################################################
+##
+## diff
+
+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 {} {
+	global ui_status_value file_states file_lists
+	global current_diff_path current_diff_side
+
+	set p $current_diff_path
+	if {$p eq {}
+		|| $current_diff_side eq {}
+		|| [catch {set s $file_states($p)}]
+		|| [lsearch -sorted -exact $file_lists($current_diff_side) $p] == -1} {
+		clear_diff
+	} else {
+		show_diff $p $current_diff_side
+	}
+}
+
+proc handle_empty_diff {} {
+	global current_diff_path file_states file_lists
+
+	set path $current_diff_path
+	set s $file_states($path)
+	if {[lindex $s 0] ne {_M}} return
+
+	info_popup "No differences detected.
+
+[short_path $path] 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."
+
+	clear_diff
+	display_file $path __
+	rescan {set ui_status_value {Ready.}} 0
+}
+
+proc show_diff {path w {lno {}}} {
+	global file_states file_lists
+	global is_3way_diff diff_active repo_config
+	global ui_diff ui_status_value ui_index ui_workdir
+	global current_diff_path current_diff_side current_diff_header
+
+	if {$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
+	}
+
+	set s $file_states($path)
+	set m [lindex $s 0]
+	set is_3way_diff 0
+	set diff_active 1
+	set current_diff_path $path
+	set current_diff_side $w
+	set current_diff_header {}
+	set ui_status_value "Loading diff of [escape_path $path]..."
+
+	# - Git won't give us the diff, there's nothing to compare to!
+	#
+	if {$m eq {_O}} {
+		set max_sz [expr {128 * 1024}]
+		if {[catch {
+				set fd [open $path r]
+				set content [read $fd $max_sz]
+				close $fd
+				set sz [file size $path]
+			} err ]} {
+			set diff_active 0
+			unlock_index
+			set ui_status_value "Unable to display [escape_path $path]"
+			error_popup "Error loading file:\n\n$err"
+			return
+		}
+		$ui_diff conf -state normal
+		if {![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_@
+		}
+		if {[string first "\0" $content] != -1} {
+			$ui_diff insert end \
+				"* Binary file (not showing content)." \
+				d_@
+		} else {
+			if {$sz > $max_sz} {
+				$ui_diff insert end \
+"* Untracked file is $sz bytes.
+* Showing only first $max_sz bytes.
+" d_@
+			}
+			$ui_diff insert end $content
+			if {$sz > $max_sz} {
+				$ui_diff insert end "
+* Untracked file clipped here by [appname].
+* To see the entire file, use an external editor.
+" d_@
+			}
+		}
+		$ui_diff conf -state disabled
+		set diff_active 0
+		unlock_index
+		set ui_status_value {Ready.}
+		return
+	}
+
+	set cmd [list | git]
+	if {$w eq $ui_index} {
+		lappend cmd diff-index
+		lappend cmd --cached
+	} elseif {$w eq $ui_workdir} {
+		if {[string index $m 0] eq {U}} {
+			lappend cmd diff
+		} else {
+			lappend cmd diff-files
+		}
+	}
+
+	lappend cmd -p
+	lappend cmd --no-color
+	if {$repo_config(gui.diffcontext) > 0} {
+		lappend cmd "-U$repo_config(gui.diffcontext)"
+	}
+	if {$w eq $ui_index} {
+		lappend cmd [PARENT]
+	}
+	lappend cmd --
+	lappend cmd $path
+
+	if {[catch {set fd [open $cmd r]} err]} {
+		set diff_active 0
+		unlock_index
+		set ui_status_value "Unable to display [escape_path $path]"
+		error_popup "Error loading diff:\n\n$err"
+		return
+	}
+
+	fconfigure $fd \
+		-blocking 0 \
+		-encoding binary \
+		-translation binary
+	fileevent $fd readable [list read_diff $fd]
+}
+
+proc read_diff {fd} {
+	global ui_diff ui_status_value diff_active
+	global is_3way_diff current_diff_header
+
+	$ui_diff conf -state normal
+	while {[gets $fd line] >= 0} {
+		# -- 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]} {
+			append current_diff_header $line "\n"
+			continue
+		}
+		if {[string match {index *} $line]} continue
+		if {$line eq {deleted file mode 120000}} {
+			set line "deleted symlink"
+		}
+
+		# -- Automatically detect if this is a 3 way diff.
+		#
+		if {[string match {@@@ *} $line]} {set is_3way_diff 1}
+
+		if {[string match {mode *} $line]
+			|| [string match {new file *} $line]
+			|| [string match {deleted file *} $line]
+			|| [string match {Binary files * and * differ} $line]
+			|| $line eq {\ No newline at end of file}
+			|| [regexp {^\* Unmerged path } $line]} {
+			set tags {}
+		} elseif {$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_--}
+			{++} {
+				if {[regexp {^\+\+([<>]{7} |={7})} $line _g op]} {
+					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 {}
+			}
+			}
+		} else {
+			set op [string index $line 0]
+			switch -- $op {
+			{ } {set tags {}}
+			{@} {set tags d_@}
+			{-} {set tags d_-}
+			{+} {
+				if {[regexp {^\+([<>]{7} |={7})} $line _g op]} {
+					set line [string replace $line 0 0 { }]
+					set tags d$op
+				} else {
+					set tags d_+
+				}
+			}
+			default {
+				puts "error: Unhandled 2 way diff marker: {$op}"
+				set tags {}
+			}
+			}
+		}
+		$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
+	}
+	$ui_diff conf -state disabled
+
+	if {[eof $fd]} {
+		close $fd
+		set diff_active 0
+		unlock_index
+		set ui_status_value {Ready.}
+
+		if {[$ui_diff index end] eq {2.0}} {
+			handle_empty_diff
+		}
+	}
+}
+
+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 {git apply --cached --whitespace=nowarn}
+	set mi [lindex $file_states($current_diff_path) 0]
+	if {$current_diff_side eq $ui_index} {
+		set mode unstage
+		lappend apply_cmd --reverse
+		if {[string index $mi 0] ne {M}} {
+			unlock_index
+			return
+		}
+	} else {
+		set mode stage
+		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 p [open "| $apply_cmd" w]
+		fconfigure $p -translation binary -encoding binary
+		puts -nonewline $p $current_diff_header
+		puts -nonewline $p [$ui_diff get $s_lno $e_lno]
+		close $p} err]} {
+		error_popup "Failed to $mode selected hunk.\n\n$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 $mi
+	if {$o eq {_}} {
+		clear_diff
+	}
+}
+
+######################################################################
+##
+## commit
+
+proc load_last_commit {} {
+	global HEAD PARENT MERGE_HEAD commit_type ui_comm
+	global repo_config
+
+	if {[llength $PARENT] == 0} {
+		error_popup {There is nothing to amend.
+
+You are about to create the initial commit.
+There is no commit before this to amend.
+}
+		return
+	}
+
+	repository_state curType curHEAD curMERGE_HEAD
+	if {$curType eq {merge}} {
+		error_popup {Cannot amend while merging.
+
+You are currently in the middle of a merge that
+has not been fully completed.  You cannot amend
+the prior commit unless you first abort the
+current merge activity.
+}
+		return
+	}
+
+	set msg {}
+	set parents [list]
+	if {[catch {
+			set fd [open "| git cat-file commit $curHEAD" r]
+			fconfigure $fd -encoding binary -translation lf
+			if {[catch {set enc $repo_config(i18n.commitencoding)}]} {
+				set enc utf-8
+			}
+			while {[gets $fd line] > 0} {
+				if {[string match {parent *} $line]} {
+					lappend parents [string range $line 7 end]
+				} elseif {[string match {encoding *} $line]} {
+					set enc [string tolower [string range $line 9 end]]
+				}
+			}
+			fconfigure $fd -encoding $enc
+			set msg [string trim [read $fd]]
+			close $fd
+		} err]} {
+		error_popup "Error loading commit data for amend:\n\n$err"
+		return
+	}
+
+	set HEAD $curHEAD
+	set PARENT $parents
+	set MERGE_HEAD [list]
+	switch -- [llength $parents] {
+	0       {set commit_type amend-initial}
+	1       {set commit_type amend}
+	default {set commit_type amend-merge}
+	}
+
+	$ui_comm delete 0.0 end
+	$ui_comm insert end $msg
+	$ui_comm edit reset
+	$ui_comm edit modified false
+	rescan {set ui_status_value {Ready.}}
+}
+
+proc create_new_commit {} {
+	global commit_type ui_comm
+
+	set commit_type normal
+	$ui_comm delete 0.0 end
+	$ui_comm edit reset
+	$ui_comm edit modified false
+	rescan {set ui_status_value {Ready.}}
+}
+
+set GIT_COMMITTER_IDENT {}
+
+proc committer_ident {} {
+	global GIT_COMMITTER_IDENT
+
+	if {$GIT_COMMITTER_IDENT eq {}} {
+		if {[catch {set me [exec git var GIT_COMMITTER_IDENT]} err]} {
+			error_popup "Unable to obtain your identity:\n\n$err"
+			return {}
+		}
+		if {![regexp {^(.*) [0-9]+ [-+0-9]+$} \
+			$me me GIT_COMMITTER_IDENT]} {
+			error_popup "Invalid GIT_COMMITTER_IDENT:\n\n$me"
+			return {}
+		}
+	}
+
+	return $GIT_COMMI