git-gui: Teach the gui how to uninclude a file.

Sometimes the user may want to keep their working directory file to be
the same content but they don't want it to be part of the current commit
anymore.  In this case we need to undo any changes made to the index
for that file (by reloading the info from HEAD or removing the file
from the index) but leave the working directory alone.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

git-gui

@@ -1,4 +1,3 @@
-#!/bin/sh
 # Tcl ignores the next line -*- tcl -*- \
 exec wish "$0" -- "$@"
 
@@ -369,12 +368,14 @@ proc read_diff_index {fd after} {
 		set z2 [string first "\0" $buf_rdi $z1]
 		if {$z2 == -1} break
 
-		set c $z2
-		incr z2 -1
-		display_file \
-			[string range $buf_rdi $z1 $z2] \
-			[string index $buf_rdi [expr {$z1 - 2}]]?
 		incr c
+		set n [split [string range $buf_rdi $c [expr {$z1 - 2}]] { }]
+		merge_state \
+			[string range $buf_rdi $z1 [expr {$z2 - 1}]] \
+			[lindex $n 4]? \
+			[list [lindex $n 0] [lindex $n 2]] \
+			[list]
+		set c $z2
 	}
 	if {$c < $n} {
 		set buf_rdi [string range $buf_rdi $c end]
@@ -398,12 +399,14 @@ proc read_diff_files {fd after} {
 		set z2 [string first "\0" $buf_rdf $z1]
 		if {$z2 == -1} break
 
-		set c $z2
-		incr z2 -1
-		display_file \
-			[string range $buf_rdf $z1 $z2] \
-			?[string index $buf_rdf [expr {$z1 - 2}]]
 		incr c
+		set n [split [string range $buf_rdf $c [expr {$z1 - 2}]] { }]
+		merge_state \
+			[string range $buf_rdf $z1 [expr {$z2 - 1}]] \
+			?[lindex $n 4] \
+			[list] \
+			[list [lindex $n 0] [lindex $n 2]]
+		set c $z2
 	}
 	if {$c < $n} {
 		set buf_rdf [string range $buf_rdf $c end]
@@ -421,7 +424,7 @@ proc read_ls_others {fd after} {
 	set pck [split $buf_rlo "\0"]
 	set buf_rlo [lindex $pck end]
 	foreach p [lrange $pck 0 end-1] {
-		display_file $p ?O
+		merge_state $p ?O
 	}
 	rescan_done $fd buf_rlo $after
 }
@@ -1165,7 +1168,7 @@ proc short_path {path} {
 
 set next_icon_id 0
 
-proc merge_state {path new_state} {
+proc merge_state {path new_state {head_info {}} {index_info {}}} {
 	global file_states next_icon_id
 
 	set s0 [string index $new_state 0]
@@ -1177,30 +1180,31 @@ proc merge_state {path new_state} {
 	} else {
 		set state [lindex $info 0]
 		set icon [lindex $info 1]
+		if {$head_info eq {}}  {set head_info  [lindex $info 2]}
+		if {$index_info eq {}} {set index_info [lindex $info 3]}
 	}
 
-	if {$s0 eq {?}} {
+	if     {$s0 eq {?}} {set s0 [string index $state 0]} \
-		set s0 [string index $state 0]
+	elseif {$s0 eq {_}} {set s0 _}
-	} elseif {$s0 eq {_}} {
+
-		set s0 _
+	if     {$s1 eq {?}} {set s1 [string index $state 1]} \
+	elseif {$s1 eq {_}} {set s1 _}
+
+	if {$s0 ne {_} && [string index $state 0] eq {_}
+		&& $head_info eq {}} {
+		set head_info $index_info
 	}
 
-	if {$s1 eq {?}} {
+	set file_states($path) [list $s0$s1 $icon \
-		set s1 [string index $state 1]
+		$head_info $index_info \
-	} elseif {$s1 eq {_}} {
+		]
-		set s1 _
-	}
-
-	set file_states($path) [list $s0$s1 $icon]
 	return $state
 }
 
 proc display_file {path state} {
-	global file_states file_lists selected_paths rescan_active
+	global file_states file_lists selected_paths
 
 	set old_m [merge_state $path $state]
-	if {$rescan_active > 0} return
-
 	set s $file_states($path)
 	set new_m [lindex $s 0]
 	set new_w [mapcol $new_m $path] 
@@ -1278,6 +1282,80 @@ proc display_all_files {} {
 	$ui_other conf -state disabled
 }
 
+proc update_indexinfo {msg pathList after} {
+	global update_index_cp ui_status_value
+
+	if {![lock_index update]} return
+
+	set update_index_cp 0
+	set pathList [lsort $pathList]
+	set totalCnt [llength $pathList]
+	set batch [expr {int($totalCnt * .01) + 1}]
+	if {$batch > 25} {set batch 25}
+
+	set ui_status_value [format \
+		"$msg... %i/%i files (%.2f%%)" \
+		$update_index_cp \
+		$totalCnt \
+		0.0]
+	set fd [open "| git update-index -z --index-info" w]
+	fconfigure $fd \
+		-blocking 0 \
+		-buffering full \
+		-buffersize 512 \
+		-translation binary
+	fileevent $fd writable [list \
+		write_update_indexinfo \
+		$fd \
+		$pathList \
+		$totalCnt \
+		$batch \
+		$msg \
+		$after \
+		]
+}
+
+proc write_update_indexinfo {fd pathList totalCnt batch msg after} {
+	global update_index_cp ui_status_value
+	global file_states current_diff
+
+	if {$update_index_cp >= $totalCnt} {
+		close $fd
+		unlock_index
+		uplevel #0 $after
+		return
+	}
+
+	for {set i $batch} \
+		{$update_index_cp < $totalCnt && $i > 0} \
+		{incr i -1} {
+		set path [lindex $pathList $update_index_cp]
+		incr update_index_cp
+
+		set s $file_states($path)
+		switch -glob -- [lindex $s 0] {
+		A? {set new _O}
+		M? {set new _M}
+		D? {set new _?}
+		?? {continue}
+		}
+		set info [lindex $s 2]
+		if {$info eq {}} continue
+
+		puts -nonewline $fd $info
+		puts -nonewline $fd "\t"
+		puts -nonewline $fd $path
+		puts -nonewline $fd "\0"
+		display_file $path $new
+	}
+
+	set ui_status_value [format \
+		"$msg... %i/%i files (%.2f%%)" \
+		$update_index_cp \
+		$totalCnt \
+		[expr {100.0 * $update_index_cp / $totalCnt}]]
+}
+
 proc update_index {msg pathList after} {
 	global update_index_cp ui_status_value
 
@@ -1881,6 +1959,49 @@ proc do_rescan {} {
 	rescan {set ui_status_value {Ready.}}
 }
 
+proc remove_helper {txt paths} {
+	global file_states current_diff
+
+	if {![lock_index begin-update]} return
+
+	set pathList [list]
+	set after {}
+	foreach path $paths {
+		switch -glob -- [lindex $file_states($path) 0] {
+		A? -
+		M? -
+		D? {
+			lappend pathList $path
+			if {$path eq $current_diff} {
+				set after {reshow_diff;}
+			}
+		}
+		}
+	}
+	if {$pathList eq {}} {
+		unlock_index
+	} else {
+		update_indexinfo \
+			$txt \
+			$pathList \
+			[concat $after {set ui_status_value {Ready.}}]
+	}
+}
+
+proc do_remove_selection {} {
+	global current_diff selected_paths
+
+	if {[array size selected_paths] > 0} {
+		remove_helper \
+			{Removing selected files from commit} \
+			[array names selected_paths]
+	} elseif {$current_diff ne {}} {
+		remove_helper \
+			"Removing [short_path $current_diff] from commit" \
+			[list $current_diff]
+	}
+}
+
 proc include_helper {txt paths} {
 	global file_states current_diff
 
@@ -2525,19 +2646,27 @@ lappend disable_on_lock \
 lappend disable_on_lock \
 	[list .mbar.commit entryconf [.mbar.commit index last] -state]
 
-.mbar.commit add command -label {Include Selected Files} \
+.mbar.commit add command -label {Remove From Commit} \
+	-command do_remove_selection \
+	-font font_ui
+lappend disable_on_lock \
+	[list .mbar.commit entryconf [.mbar.commit index last] -state]
+
+.mbar.commit add command -label {Include In Commit} \
 	-command do_include_selection \
 	-font font_ui
 lappend disable_on_lock \
 	[list .mbar.commit entryconf [.mbar.commit index last] -state]
 
-.mbar.commit add command -label {Include All Files} \
+.mbar.commit add command -label {Include All} \
 	-command do_include_all \
 	-accelerator $M1T-I \
 	-font font_ui
 lappend disable_on_lock \
 	[list .mbar.commit entryconf [.mbar.commit index last] -state]
 
+.mbar.commit add separator
+
 .mbar.commit add command -label {Sign Off} \
 	-command do_signoff \
 	-accelerator $M1T-S \