git-gui: fix ANSI-color parsing
[git] / lib / diff.tcl
1 # git-gui diff viewer
2 # Copyright (C) 2006, 2007 Shawn Pearce
3
4 proc clear_diff {} {
5         global ui_diff current_diff_path current_diff_header
6         global ui_index ui_workdir
7
8         $ui_diff conf -state normal
9         $ui_diff delete 0.0 end
10         $ui_diff conf -state disabled
11
12         set current_diff_path {}
13         set current_diff_header {}
14
15         $ui_index tag remove in_diff 0.0 end
16         $ui_workdir tag remove in_diff 0.0 end
17 }
18
19 proc reshow_diff {{after {}}} {
20         global file_states file_lists
21         global current_diff_path current_diff_side
22         global ui_diff
23
24         set p $current_diff_path
25         if {$p eq {}} {
26                 # No diff is being shown.
27         } elseif {$current_diff_side eq {}} {
28                 clear_diff
29         } elseif {[catch {set s $file_states($p)}]
30                 || [lsearch -sorted -exact $file_lists($current_diff_side) $p] == -1} {
31
32                 if {[find_next_diff $current_diff_side $p {} {[^O]}]} {
33                         next_diff $after
34                 } else {
35                         clear_diff
36                 }
37         } else {
38                 set save_pos [lindex [$ui_diff yview] 0]
39                 show_diff $p $current_diff_side {} $save_pos $after
40         }
41 }
42
43 proc force_diff_encoding {enc} {
44         global current_diff_path
45         
46         if {$current_diff_path ne {}} {
47                 force_path_encoding $current_diff_path $enc
48                 reshow_diff
49         }
50 }
51
52 proc handle_empty_diff {} {
53         global current_diff_path file_states file_lists
54         global diff_empty_count
55
56         set path $current_diff_path
57         set s $file_states($path)
58         if {[lindex $s 0] ne {_M} || [has_textconv $path]} return
59
60         # Prevent infinite rescan loops
61         incr diff_empty_count
62         if {$diff_empty_count > 1} return
63
64         info_popup [mc "No differences detected.
65
66 %s has no changes.
67
68 The modification date of this file was updated by another application, but the content within the file was not changed.
69
70 A rescan will be automatically started to find other files which may have the same state." [short_path $path]]
71
72         clear_diff
73         display_file $path __
74         rescan ui_ready 0
75 }
76
77 proc show_diff {path w {lno {}} {scroll_pos {}} {callback {}}} {
78         global file_states file_lists
79         global is_3way_diff is_conflict_diff diff_active repo_config
80         global ui_diff ui_index ui_workdir
81         global current_diff_path current_diff_side current_diff_header
82         global current_diff_queue
83
84         if {$diff_active || ![lock_index read]} return
85
86         clear_diff
87         if {$lno == {}} {
88                 set lno [lsearch -sorted -exact $file_lists($w) $path]
89                 if {$lno >= 0} {
90                         incr lno
91                 }
92         }
93         if {$lno >= 1} {
94                 $w tag add in_diff $lno.0 [expr {$lno + 1}].0
95                 $w see $lno.0
96         }
97
98         set s $file_states($path)
99         set m [lindex $s 0]
100         set is_conflict_diff 0
101         set current_diff_path $path
102         set current_diff_side $w
103         set current_diff_queue {}
104         ui_status [mc "Loading diff of %s..." [escape_path $path]]
105
106         set cont_info [list $scroll_pos $callback]
107
108         if {[string first {U} $m] >= 0} {
109                 merge_load_stages $path [list show_unmerged_diff $cont_info]
110         } elseif {$m eq {_O}} {
111                 show_other_diff $path $w $m $cont_info
112         } else {
113                 start_show_diff $cont_info
114         }
115 }
116
117 proc show_unmerged_diff {cont_info} {
118         global current_diff_path current_diff_side
119         global merge_stages ui_diff is_conflict_diff
120         global current_diff_queue
121
122         if {$merge_stages(2) eq {}} {
123                 set is_conflict_diff 1
124                 lappend current_diff_queue \
125                         [list [mc "LOCAL: deleted\nREMOTE:\n"] d======= \
126                             [list ":1:$current_diff_path" ":3:$current_diff_path"]]
127         } elseif {$merge_stages(3) eq {}} {
128                 set is_conflict_diff 1
129                 lappend current_diff_queue \
130                         [list [mc "REMOTE: deleted\nLOCAL:\n"] d======= \
131                             [list ":1:$current_diff_path" ":2:$current_diff_path"]]
132         } elseif {[lindex $merge_stages(1) 0] eq {120000}
133                 || [lindex $merge_stages(2) 0] eq {120000}
134                 || [lindex $merge_stages(3) 0] eq {120000}} {
135                 set is_conflict_diff 1
136                 lappend current_diff_queue \
137                         [list [mc "LOCAL:\n"] d======= \
138                             [list ":1:$current_diff_path" ":2:$current_diff_path"]]
139                 lappend current_diff_queue \
140                         [list [mc "REMOTE:\n"] d======= \
141                             [list ":1:$current_diff_path" ":3:$current_diff_path"]]
142         } else {
143                 start_show_diff $cont_info
144                 return
145         }
146
147         advance_diff_queue $cont_info
148 }
149
150 proc advance_diff_queue {cont_info} {
151         global current_diff_queue ui_diff
152
153         set item [lindex $current_diff_queue 0]
154         set current_diff_queue [lrange $current_diff_queue 1 end]
155
156         $ui_diff conf -state normal
157         $ui_diff insert end [lindex $item 0] [lindex $item 1]
158         $ui_diff conf -state disabled
159
160         start_show_diff $cont_info [lindex $item 2]
161 }
162
163 proc show_other_diff {path w m cont_info} {
164         global file_states file_lists
165         global is_3way_diff diff_active repo_config
166         global ui_diff ui_index ui_workdir
167         global current_diff_path current_diff_side current_diff_header
168
169         # - Git won't give us the diff, there's nothing to compare to!
170         #
171         if {$m eq {_O}} {
172                 set max_sz 100000
173                 set type unknown
174                 if {[catch {
175                                 set type [file type $path]
176                                 switch -- $type {
177                                 directory {
178                                         set type submodule
179                                         set content {}
180                                         set sz 0
181                                 }
182                                 link {
183                                         set content [file readlink $path]
184                                         set sz [string length $content]
185                                 }
186                                 file {
187                                         set fd [open $path r]
188                                         fconfigure $fd \
189                                                 -eofchar {} \
190                                                 -encoding [get_path_encoding $path]
191                                         set content [read $fd $max_sz]
192                                         close $fd
193                                         set sz [file size $path]
194                                 }
195                                 default {
196                                         error "'$type' not supported"
197                                 }
198                                 }
199                         } err ]} {
200                         set diff_active 0
201                         unlock_index
202                         ui_status [mc "Unable to display %s" [escape_path $path]]
203                         error_popup [strcat [mc "Error loading file:"] "\n\n$err"]
204                         return
205                 }
206                 $ui_diff conf -state normal
207                 if {$type eq {submodule}} {
208                         $ui_diff insert end [append \
209                                 "* " \
210                                 [mc "Git Repository (subproject)"] \
211                                 "\n"] d_@
212                 } elseif {![catch {set type [exec file $path]}]} {
213                         set n [string length $path]
214                         if {[string equal -length $n $path $type]} {
215                                 set type [string range $type $n end]
216                                 regsub {^:?\s*} $type {} type
217                         }
218                         $ui_diff insert end "* $type\n" d_@
219                 }
220                 if {[string first "\0" $content] != -1} {
221                         $ui_diff insert end \
222                                 [mc "* Binary file (not showing content)."] \
223                                 d_@
224                 } else {
225                         if {$sz > $max_sz} {
226                                 $ui_diff insert end [mc \
227 "* Untracked file is %d bytes.
228 * Showing only first %d bytes.
229 " $sz $max_sz] d_@
230                         }
231                         $ui_diff insert end $content
232                         if {$sz > $max_sz} {
233                                 $ui_diff insert end [mc "
234 * Untracked file clipped here by %s.
235 * To see the entire file, use an external editor.
236 " [appname]] d_@
237                         }
238                 }
239                 $ui_diff conf -state disabled
240                 set diff_active 0
241                 unlock_index
242                 set scroll_pos [lindex $cont_info 0]
243                 if {$scroll_pos ne {}} {
244                         update
245                         $ui_diff yview moveto $scroll_pos
246                 }
247                 ui_ready
248                 set callback [lindex $cont_info 1]
249                 if {$callback ne {}} {
250                         eval $callback
251                 }
252                 return
253         }
254 }
255
256 proc start_show_diff {cont_info {add_opts {}}} {
257         global file_states file_lists
258         global is_3way_diff is_submodule_diff diff_active repo_config
259         global ui_diff ui_index ui_workdir
260         global current_diff_path current_diff_side current_diff_header
261
262         set path $current_diff_path
263         set w $current_diff_side
264
265         set s $file_states($path)
266         set m [lindex $s 0]
267         set is_3way_diff 0
268         set is_submodule_diff 0
269         set diff_active 1
270         set current_diff_header {}
271
272         set cmd [list]
273         if {$w eq $ui_index} {
274                 lappend cmd diff-index
275                 lappend cmd --cached
276         } elseif {$w eq $ui_workdir} {
277                 if {[string first {U} $m] >= 0} {
278                         lappend cmd diff
279                 } else {
280                         lappend cmd diff-files
281                 }
282         }
283         if {![is_config_false gui.textconv] && [git-version >= 1.6.1]} {
284                 lappend cmd --textconv
285         }
286
287         if {[string match {160000 *} [lindex $s 2]]
288          || [string match {160000 *} [lindex $s 3]]} {
289                 set is_submodule_diff 1
290
291                 if {[git-version >= "1.6.6"]} {
292                         lappend cmd --submodule
293                 }
294         }
295
296         lappend cmd -p
297         lappend cmd --color
298         if {$repo_config(gui.diffcontext) >= 1} {
299                 lappend cmd "-U$repo_config(gui.diffcontext)"
300         }
301         if {$w eq $ui_index} {
302                 lappend cmd [PARENT]
303         }
304         if {$add_opts ne {}} {
305                 eval lappend cmd $add_opts
306         } else {
307                 lappend cmd --
308                 lappend cmd $path
309         }
310
311         if {$is_submodule_diff && [git-version < "1.6.6"]} {
312                 if {$w eq $ui_index} {
313                         set cmd [list submodule summary --cached -- $path]
314                 } else {
315                         set cmd [list submodule summary --files -- $path]
316                 }
317         }
318
319         if {[catch {set fd [eval git_read --nice $cmd]} err]} {
320                 set diff_active 0
321                 unlock_index
322                 ui_status [mc "Unable to display %s" [escape_path $path]]
323                 error_popup [strcat [mc "Error loading diff:"] "\n\n$err"]
324                 return
325         }
326
327         set ::current_diff_inheader 1
328         fconfigure $fd \
329                 -blocking 0 \
330                 -encoding [get_path_encoding $path] \
331                 -translation lf
332         fileevent $fd readable [list read_diff $fd $cont_info]
333 }
334
335 proc parse_color_line {line} {
336         set start 0
337         set result ""
338         set markup [list]
339         set regexp {\033\[((?:\d+;)*\d+)?m}
340         set need_reset 0
341         while {[regexp -indices -start $start $regexp $line match code]} {
342                 foreach {begin end} $match break
343                 append result [string range $line $start [expr {$begin - 1}]]
344                 set pos [string length $result]
345                 set col [eval [linsert $code 0 string range $line]]
346                 set start [incr end]
347                 if {$col eq "0" || $col eq ""} {
348                         if {!$need_reset} continue
349                         set need_reset 0
350                 } else {
351                         set need_reset 1
352                 }
353                 lappend markup $pos $col
354         }
355         append result [string range $line $start end]
356         if {[llength $markup] < 4} {set markup {}}
357         return [list $result $markup]
358 }
359
360 proc read_diff {fd cont_info} {
361         global ui_diff diff_active is_submodule_diff
362         global is_3way_diff is_conflict_diff current_diff_header
363         global current_diff_queue
364         global diff_empty_count
365
366         $ui_diff conf -state normal
367         while {[gets $fd line] >= 0} {
368                 foreach {line markup} [parse_color_line $line] break
369                 set line [string map {\033 ^} $line]
370
371                 # -- Cleanup uninteresting diff header lines.
372                 #
373                 if {$::current_diff_inheader} {
374                         if {   [string match {diff --git *}      $line]
375                             || [string match {diff --cc *}       $line]
376                             || [string match {diff --combined *} $line]
377                             || [string match {--- *}             $line]
378                             || [string match {+++ *}             $line]} {
379                                 append current_diff_header $line "\n"
380                                 continue
381                         }
382                 }
383                 if {[string match {index *} $line]} continue
384                 if {$line eq {deleted file mode 120000}} {
385                         set line "deleted symlink"
386                 }
387                 set ::current_diff_inheader 0
388
389                 # -- Automatically detect if this is a 3 way diff.
390                 #
391                 if {[string match {@@@ *} $line]} {set is_3way_diff 1}
392
393                 if {[string match {mode *} $line]
394                         || [string match {new file *} $line]
395                         || [regexp {^(old|new) mode *} $line]
396                         || [string match {deleted file *} $line]
397                         || [string match {deleted symlink} $line]
398                         || [string match {Binary files * and * differ} $line]
399                         || $line eq {\ No newline at end of file}
400                         || [regexp {^\* Unmerged path } $line]} {
401                         set tags {}
402                 } elseif {$is_3way_diff} {
403                         set op [string range $line 0 1]
404                         switch -- $op {
405                         {  } {set tags {}}
406                         {@@} {set tags d_@}
407                         { +} {set tags d_s+}
408                         { -} {set tags d_s-}
409                         {+ } {set tags d_+s}
410                         {- } {set tags d_-s}
411                         {--} {set tags d_--}
412                         {++} {
413                                 if {[regexp {^\+\+([<>]{7} |={7})} $line _g op]} {
414                                         set is_conflict_diff 1
415                                         set line [string replace $line 0 1 {  }]
416                                         set tags d$op
417                                 } else {
418                                         set tags d_++
419                                 }
420                         }
421                         default {
422                                 puts "error: Unhandled 3 way diff marker: {$op}"
423                                 set tags {}
424                         }
425                         }
426                 } elseif {$is_submodule_diff} {
427                         if {$line == ""} continue
428                         if {[regexp {^Submodule } $line]} {
429                                 set tags d_@
430                         } elseif {[regexp {^\* } $line]} {
431                                 set line [string replace $line 0 1 {Submodule }]
432                                 set tags d_@
433                         } else {
434                                 set op [string range $line 0 2]
435                                 switch -- $op {
436                                 {  <} {set tags d_-}
437                                 {  >} {set tags d_+}
438                                 {  W} {set tags {}}
439                                 default {
440                                         puts "error: Unhandled submodule diff marker: {$op}"
441                                         set tags {}
442                                 }
443                                 }
444                         }
445                 } else {
446                         set op [string index $line 0]
447                         switch -- $op {
448                         { } {set tags {}}
449                         {@} {set tags d_@}
450                         {-} {set tags d_-}
451                         {+} {
452                                 if {[regexp {^\+([<>]{7} |={7})} $line _g op]} {
453                                         set is_conflict_diff 1
454                                         set tags d$op
455                                 } else {
456                                         set tags d_+
457                                 }
458                         }
459                         default {
460                                 puts "error: Unhandled 2 way diff marker: {$op}"
461                                 set tags {}
462                         }
463                         }
464                 }
465                 set mark [$ui_diff index "end - 1 line linestart"]
466                 $ui_diff insert end $line $tags
467                 if {[string index $line end] eq "\r"} {
468                         $ui_diff tag add d_cr {end - 2c}
469                 }
470                 $ui_diff insert end "\n" $tags
471
472                 foreach {posbegin colbegin posend colend} $markup {
473                         set prefix clr
474                         foreach style [split $colbegin ";"] {
475                                 if {$style eq "7"} {append prefix i; continue}
476                                 if {$style < 30 || $style > 47} {continue}
477                                 set a "$mark linestart + $posbegin chars"
478                                 set b "$mark linestart + $posend chars"
479                                 catch {$ui_diff tag add $prefix$style $a $b}
480                         }
481                 }
482         }
483         $ui_diff conf -state disabled
484
485         if {[eof $fd]} {
486                 close $fd
487
488                 if {$current_diff_queue ne {}} {
489                         advance_diff_queue $cont_info
490                         return
491                 }
492
493                 set diff_active 0
494                 unlock_index
495                 set scroll_pos [lindex $cont_info 0]
496                 if {$scroll_pos ne {}} {
497                         update
498                         $ui_diff yview moveto $scroll_pos
499                 }
500                 ui_ready
501
502                 if {[$ui_diff index end] eq {2.0}} {
503                         handle_empty_diff
504                 } else {
505                         set diff_empty_count 0
506                 }
507
508                 set callback [lindex $cont_info 1]
509                 if {$callback ne {}} {
510                         eval $callback
511                 }
512         }
513 }
514
515 proc apply_hunk {x y} {
516         global current_diff_path current_diff_header current_diff_side
517         global ui_diff ui_index file_states
518
519         if {$current_diff_path eq {} || $current_diff_header eq {}} return
520         if {![lock_index apply_hunk]} return
521
522         set apply_cmd {apply --cached --whitespace=nowarn}
523         set mi [lindex $file_states($current_diff_path) 0]
524         if {$current_diff_side eq $ui_index} {
525                 set failed_msg [mc "Failed to unstage selected hunk."]
526                 lappend apply_cmd --reverse
527                 if {[string index $mi 0] ne {M}} {
528                         unlock_index
529                         return
530                 }
531         } else {
532                 set failed_msg [mc "Failed to stage selected hunk."]
533                 if {[string index $mi 1] ne {M}} {
534                         unlock_index
535                         return
536                 }
537         }
538
539         set s_lno [lindex [split [$ui_diff index @$x,$y] .] 0]
540         set s_lno [$ui_diff search -backwards -regexp ^@@ $s_lno.0 0.0]
541         if {$s_lno eq {}} {
542                 unlock_index
543                 return
544         }
545
546         set e_lno [$ui_diff search -forwards -regexp ^@@ "$s_lno + 1 lines" end]
547         if {$e_lno eq {}} {
548                 set e_lno end
549         }
550
551         if {[catch {
552                 set enc [get_path_encoding $current_diff_path]
553                 set p [eval git_write $apply_cmd]
554                 fconfigure $p -translation binary -encoding $enc
555                 puts -nonewline $p $current_diff_header
556                 puts -nonewline $p [$ui_diff get $s_lno $e_lno]
557                 close $p} err]} {
558                 error_popup [append $failed_msg "\n\n$err"]
559                 unlock_index
560                 return
561         }
562
563         $ui_diff conf -state normal
564         $ui_diff delete $s_lno $e_lno
565         $ui_diff conf -state disabled
566
567         if {[$ui_diff get 1.0 end] eq "\n"} {
568                 set o _
569         } else {
570                 set o ?
571         }
572
573         if {$current_diff_side eq $ui_index} {
574                 set mi ${o}M
575         } elseif {[string index $mi 0] eq {_}} {
576                 set mi M$o
577         } else {
578                 set mi ?$o
579         }
580         unlock_index
581         display_file $current_diff_path $mi
582         # This should trigger shift to the next changed file
583         if {$o eq {_}} {
584                 reshow_diff
585         }
586 }
587
588 proc apply_range_or_line {x y} {
589         global current_diff_path current_diff_header current_diff_side
590         global ui_diff ui_index file_states
591
592         set selected [$ui_diff tag nextrange sel 0.0]
593
594         if {$selected == {}} {
595                 set first [$ui_diff index "@$x,$y"]
596                 set last $first
597         } else {
598                 set first [lindex $selected 0]
599                 set last [lindex $selected 1]
600         }
601
602         set first_l [$ui_diff index "$first linestart"]
603         set last_l [$ui_diff index "$last lineend"]
604
605         if {$current_diff_path eq {} || $current_diff_header eq {}} return
606         if {![lock_index apply_hunk]} return
607
608         set apply_cmd {apply --cached --whitespace=nowarn}
609         set mi [lindex $file_states($current_diff_path) 0]
610         if {$current_diff_side eq $ui_index} {
611                 set failed_msg [mc "Failed to unstage selected line."]
612                 set to_context {+}
613                 lappend apply_cmd --reverse
614                 if {[string index $mi 0] ne {M}} {
615                         unlock_index
616                         return
617                 }
618         } else {
619                 set failed_msg [mc "Failed to stage selected line."]
620                 set to_context {-}
621                 if {[string index $mi 1] ne {M}} {
622                         unlock_index
623                         return
624                 }
625         }
626
627         set wholepatch {}
628
629         while {$first_l < $last_l} {
630                 set i_l [$ui_diff search -backwards -regexp ^@@ $first_l 0.0]
631                 if {$i_l eq {}} {
632                         # If there's not a @@ above, then the selected range
633                         # must have come before the first_l @@
634                         set i_l [$ui_diff search -regexp ^@@ $first_l $last_l]
635                 }
636                 if {$i_l eq {}} {
637                         unlock_index
638                         return
639                 }
640                 # $i_l is now at the beginning of a line
641
642                 # pick start line number from hunk header
643                 set hh [$ui_diff get $i_l "$i_l + 1 lines"]
644                 set hh [lindex [split $hh ,] 0]
645                 set hln [lindex [split $hh -] 1]
646
647                 # There is a special situation to take care of. Consider this
648                 # hunk:
649                 #
650                 #    @@ -10,4 +10,4 @@
651                 #     context before
652                 #    -old 1
653                 #    -old 2
654                 #    +new 1
655                 #    +new 2
656                 #     context after
657                 #
658                 # We used to keep the context lines in the order they appear in
659                 # the hunk. But then it is not possible to correctly stage only
660                 # "-old 1" and "+new 1" - it would result in this staged text:
661                 #
662                 #    context before
663                 #    old 2
664                 #    new 1
665                 #    context after
666                 #
667                 # (By symmetry it is not possible to *un*stage "old 2" and "new
668                 # 2".)
669                 #
670                 # We resolve the problem by introducing an asymmetry, namely,
671                 # when a "+" line is *staged*, it is moved in front of the
672                 # context lines that are generated from the "-" lines that are
673                 # immediately before the "+" block. That is, we construct this
674                 # patch:
675                 #
676                 #    @@ -10,4 +10,5 @@
677                 #     context before
678                 #    +new 1
679                 #     old 1
680                 #     old 2
681                 #     context after
682                 #
683                 # But we do *not* treat "-" lines that are *un*staged in a
684                 # special way.
685                 #
686                 # With this asymmetry it is possible to stage the change "old
687                 # 1" -> "new 1" directly, and to stage the change "old 2" ->
688                 # "new 2" by first staging the entire hunk and then unstaging
689                 # the change "old 1" -> "new 1".
690                 #
691                 # Applying multiple lines adds complexity to the special
692                 # situation.  The pre_context must be moved after the entire
693                 # first block of consecutive staged "+" lines, so that
694                 # staging both additions gives the following patch:
695                 #
696                 #    @@ -10,4 +10,6 @@
697                 #     context before
698                 #    +new 1
699                 #    +new 2
700                 #     old 1
701                 #     old 2
702                 #     context after
703
704                 # This is non-empty if and only if we are _staging_ changes;
705                 # then it accumulates the consecutive "-" lines (after
706                 # converting them to context lines) in order to be moved after
707                 # "+" change lines.
708                 set pre_context {}
709
710                 set n 0
711                 set m 0
712                 set i_l [$ui_diff index "$i_l + 1 lines"]
713                 set patch {}
714                 while {[$ui_diff compare $i_l < "end - 1 chars"] &&
715                        [$ui_diff get $i_l "$i_l + 2 chars"] ne {@@}} {
716                         set next_l [$ui_diff index "$i_l + 1 lines"]
717                         set c1 [$ui_diff get $i_l]
718                         if {[$ui_diff compare $first_l <= $i_l] &&
719                             [$ui_diff compare $i_l < $last_l] &&
720                             ($c1 eq {-} || $c1 eq {+})} {
721                                 # a line to stage/unstage
722                                 set ln [$ui_diff get $i_l $next_l]
723                                 if {$c1 eq {-}} {
724                                         set n [expr $n+1]
725                                         set patch "$patch$pre_context$ln"
726                                         set pre_context {}
727                                 } else {
728                                         set m [expr $m+1]
729                                         set patch "$patch$ln"
730                                 }
731                         } elseif {$c1 ne {-} && $c1 ne {+}} {
732                                 # context line
733                                 set ln [$ui_diff get $i_l $next_l]
734                                 set patch "$patch$pre_context$ln"
735                                 set n [expr $n+1]
736                                 set m [expr $m+1]
737                                 set pre_context {}
738                         } elseif {$c1 eq $to_context} {
739                                 # turn change line into context line
740                                 set ln [$ui_diff get "$i_l + 1 chars" $next_l]
741                                 if {$c1 eq {-}} {
742                                         set pre_context "$pre_context $ln"
743                                 } else {
744                                         set patch "$patch $ln"
745                                 }
746                                 set n [expr $n+1]
747                                 set m [expr $m+1]
748                         } else {
749                                 # a change in the opposite direction of
750                                 # to_context which is outside the range of
751                                 # lines to apply.
752                                 set patch "$patch$pre_context"
753                                 set pre_context {}
754                         }
755                         set i_l $next_l
756                 }
757                 set patch "$patch$pre_context"
758                 set wholepatch "$wholepatch@@ -$hln,$n +$hln,$m @@\n$patch"
759                 set first_l [$ui_diff index "$next_l + 1 lines"]
760         }
761
762         if {[catch {
763                 set enc [get_path_encoding $current_diff_path]
764                 set p [eval git_write $apply_cmd]
765                 fconfigure $p -translation binary -encoding $enc
766                 puts -nonewline $p $current_diff_header
767                 puts -nonewline $p $wholepatch
768                 close $p} err]} {
769                 error_popup [append $failed_msg "\n\n$err"]
770         }
771
772         unlock_index
773 }