Merge branch 'maint-1.6.0' into maint
[git] / git-gui / 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
55         set path $current_diff_path
56         set s $file_states($path)
57         if {[lindex $s 0] ne {_M}} return
58
59         info_popup [mc "No differences detected.
60
61 %s has no changes.
62
63 The modification date of this file was updated by another application, but the content within the file was not changed.
64
65 A rescan will be automatically started to find other files which may have the same state." [short_path $path]]
66
67         clear_diff
68         display_file $path __
69         rescan ui_ready 0
70 }
71
72 proc show_diff {path w {lno {}} {scroll_pos {}} {callback {}}} {
73         global file_states file_lists
74         global is_3way_diff is_conflict_diff diff_active repo_config
75         global ui_diff ui_index ui_workdir
76         global current_diff_path current_diff_side current_diff_header
77         global current_diff_queue
78
79         if {$diff_active || ![lock_index read]} return
80
81         clear_diff
82         if {$lno == {}} {
83                 set lno [lsearch -sorted -exact $file_lists($w) $path]
84                 if {$lno >= 0} {
85                         incr lno
86                 }
87         }
88         if {$lno >= 1} {
89                 $w tag add in_diff $lno.0 [expr {$lno + 1}].0
90                 $w see $lno.0
91         }
92
93         set s $file_states($path)
94         set m [lindex $s 0]
95         set is_conflict_diff 0
96         set current_diff_path $path
97         set current_diff_side $w
98         set current_diff_queue {}
99         ui_status [mc "Loading diff of %s..." [escape_path $path]]
100
101         set cont_info [list $scroll_pos $callback]
102
103         if {[string first {U} $m] >= 0} {
104                 merge_load_stages $path [list show_unmerged_diff $cont_info]
105         } elseif {$m eq {_O}} {
106                 show_other_diff $path $w $m $cont_info
107         } else {
108                 start_show_diff $cont_info
109         }
110 }
111
112 proc show_unmerged_diff {cont_info} {
113         global current_diff_path current_diff_side
114         global merge_stages ui_diff is_conflict_diff
115         global current_diff_queue
116
117         if {$merge_stages(2) eq {}} {
118                 set is_conflict_diff 1
119                 lappend current_diff_queue \
120                         [list [mc "LOCAL: deleted\nREMOTE:\n"] d======= \
121                             [list ":1:$current_diff_path" ":3:$current_diff_path"]]
122         } elseif {$merge_stages(3) eq {}} {
123                 set is_conflict_diff 1
124                 lappend current_diff_queue \
125                         [list [mc "REMOTE: deleted\nLOCAL:\n"] d======= \
126                             [list ":1:$current_diff_path" ":2:$current_diff_path"]]
127         } elseif {[lindex $merge_stages(1) 0] eq {120000}
128                 || [lindex $merge_stages(2) 0] eq {120000}
129                 || [lindex $merge_stages(3) 0] eq {120000}} {
130                 set is_conflict_diff 1
131                 lappend current_diff_queue \
132                         [list [mc "LOCAL:\n"] d======= \
133                             [list ":1:$current_diff_path" ":2:$current_diff_path"]]
134                 lappend current_diff_queue \
135                         [list [mc "REMOTE:\n"] d======= \
136                             [list ":1:$current_diff_path" ":3:$current_diff_path"]]
137         } else {
138                 start_show_diff $cont_info
139                 return
140         }
141
142         advance_diff_queue $cont_info
143 }
144
145 proc advance_diff_queue {cont_info} {
146         global current_diff_queue ui_diff
147
148         set item [lindex $current_diff_queue 0]
149         set current_diff_queue [lrange $current_diff_queue 1 end]
150
151         $ui_diff conf -state normal
152         $ui_diff insert end [lindex $item 0] [lindex $item 1]
153         $ui_diff conf -state disabled
154
155         start_show_diff $cont_info [lindex $item 2]
156 }
157
158 proc show_other_diff {path w m cont_info} {
159         global file_states file_lists
160         global is_3way_diff diff_active repo_config
161         global ui_diff ui_index ui_workdir
162         global current_diff_path current_diff_side current_diff_header
163
164         # - Git won't give us the diff, there's nothing to compare to!
165         #
166         if {$m eq {_O}} {
167                 set max_sz 100000
168                 set type unknown
169                 if {[catch {
170                                 set type [file type $path]
171                                 switch -- $type {
172                                 directory {
173                                         set type submodule
174                                         set content {}
175                                         set sz 0
176                                 }
177                                 link {
178                                         set content [file readlink $path]
179                                         set sz [string length $content]
180                                 }
181                                 file {
182                                         set fd [open $path r]
183                                         fconfigure $fd \
184                                                 -eofchar {} \
185                                                 -encoding [get_path_encoding $path]
186                                         set content [read $fd $max_sz]
187                                         close $fd
188                                         set sz [file size $path]
189                                 }
190                                 default {
191                                         error "'$type' not supported"
192                                 }
193                                 }
194                         } err ]} {
195                         set diff_active 0
196                         unlock_index
197                         ui_status [mc "Unable to display %s" [escape_path $path]]
198                         error_popup [strcat [mc "Error loading file:"] "\n\n$err"]
199                         return
200                 }
201                 $ui_diff conf -state normal
202                 if {$type eq {submodule}} {
203                         $ui_diff insert end [append \
204                                 "* " \
205                                 [mc "Git Repository (subproject)"] \
206                                 "\n"] d_@
207                 } elseif {![catch {set type [exec file $path]}]} {
208                         set n [string length $path]
209                         if {[string equal -length $n $path $type]} {
210                                 set type [string range $type $n end]
211                                 regsub {^:?\s*} $type {} type
212                         }
213                         $ui_diff insert end "* $type\n" d_@
214                 }
215                 if {[string first "\0" $content] != -1} {
216                         $ui_diff insert end \
217                                 [mc "* Binary file (not showing content)."] \
218                                 d_@
219                 } else {
220                         if {$sz > $max_sz} {
221                                 $ui_diff insert end [mc \
222 "* Untracked file is %d bytes.
223 * Showing only first %d bytes.
224 " $sz $max_sz] d_@
225                         }
226                         $ui_diff insert end $content
227                         if {$sz > $max_sz} {
228                                 $ui_diff insert end [mc "
229 * Untracked file clipped here by %s.
230 * To see the entire file, use an external editor.
231 " [appname]] d_@
232                         }
233                 }
234                 $ui_diff conf -state disabled
235                 set diff_active 0
236                 unlock_index
237                 set scroll_pos [lindex $cont_info 0]
238                 if {$scroll_pos ne {}} {
239                         update
240                         $ui_diff yview moveto $scroll_pos
241                 }
242                 ui_ready
243                 set callback [lindex $cont_info 1]
244                 if {$callback ne {}} {
245                         eval $callback
246                 }
247                 return
248         }
249 }
250
251 proc start_show_diff {cont_info {add_opts {}}} {
252         global file_states file_lists
253         global is_3way_diff diff_active repo_config
254         global ui_diff ui_index ui_workdir
255         global current_diff_path current_diff_side current_diff_header
256
257         set path $current_diff_path
258         set w $current_diff_side
259
260         set s $file_states($path)
261         set m [lindex $s 0]
262         set is_3way_diff 0
263         set diff_active 1
264         set current_diff_header {}
265
266         set cmd [list]
267         if {$w eq $ui_index} {
268                 lappend cmd diff-index
269                 lappend cmd --cached
270         } elseif {$w eq $ui_workdir} {
271                 if {[string first {U} $m] >= 0} {
272                         lappend cmd diff
273                 } else {
274                         lappend cmd diff-files
275                 }
276         }
277
278         lappend cmd -p
279         lappend cmd --no-color
280         if {$repo_config(gui.diffcontext) >= 1} {
281                 lappend cmd "-U$repo_config(gui.diffcontext)"
282         }
283         if {$w eq $ui_index} {
284                 lappend cmd [PARENT]
285         }
286         if {$add_opts ne {}} {
287                 eval lappend cmd $add_opts
288         } else {
289                 lappend cmd --
290                 lappend cmd $path
291         }
292
293         if {[catch {set fd [eval git_read --nice $cmd]} err]} {
294                 set diff_active 0
295                 unlock_index
296                 ui_status [mc "Unable to display %s" [escape_path $path]]
297                 error_popup [strcat [mc "Error loading diff:"] "\n\n$err"]
298                 return
299         }
300
301         set ::current_diff_inheader 1
302         fconfigure $fd \
303                 -blocking 0 \
304                 -encoding [get_path_encoding $path] \
305                 -translation lf
306         fileevent $fd readable [list read_diff $fd $cont_info]
307 }
308
309 proc read_diff {fd cont_info} {
310         global ui_diff diff_active
311         global is_3way_diff is_conflict_diff current_diff_header
312         global current_diff_queue
313
314         $ui_diff conf -state normal
315         while {[gets $fd line] >= 0} {
316                 # -- Cleanup uninteresting diff header lines.
317                 #
318                 if {$::current_diff_inheader} {
319                         if {   [string match {diff --git *}      $line]
320                             || [string match {diff --cc *}       $line]
321                             || [string match {diff --combined *} $line]
322                             || [string match {--- *}             $line]
323                             || [string match {+++ *}             $line]} {
324                                 append current_diff_header $line "\n"
325                                 continue
326                         }
327                 }
328                 if {[string match {index *} $line]} continue
329                 if {$line eq {deleted file mode 120000}} {
330                         set line "deleted symlink"
331                 }
332                 set ::current_diff_inheader 0
333
334                 # -- Automatically detect if this is a 3 way diff.
335                 #
336                 if {[string match {@@@ *} $line]} {set is_3way_diff 1}
337
338                 if {[string match {mode *} $line]
339                         || [string match {new file *} $line]
340                         || [regexp {^(old|new) mode *} $line]
341                         || [string match {deleted file *} $line]
342                         || [string match {deleted symlink} $line]
343                         || [string match {Binary files * and * differ} $line]
344                         || $line eq {\ No newline at end of file}
345                         || [regexp {^\* Unmerged path } $line]} {
346                         set tags {}
347                 } elseif {$is_3way_diff} {
348                         set op [string range $line 0 1]
349                         switch -- $op {
350                         {  } {set tags {}}
351                         {@@} {set tags d_@}
352                         { +} {set tags d_s+}
353                         { -} {set tags d_s-}
354                         {+ } {set tags d_+s}
355                         {- } {set tags d_-s}
356                         {--} {set tags d_--}
357                         {++} {
358                                 if {[regexp {^\+\+([<>]{7} |={7})} $line _g op]} {
359                                         set is_conflict_diff 1
360                                         set line [string replace $line 0 1 {  }]
361                                         set tags d$op
362                                 } else {
363                                         set tags d_++
364                                 }
365                         }
366                         default {
367                                 puts "error: Unhandled 3 way diff marker: {$op}"
368                                 set tags {}
369                         }
370                         }
371                 } else {
372                         set op [string index $line 0]
373                         switch -- $op {
374                         { } {set tags {}}
375                         {@} {set tags d_@}
376                         {-} {set tags d_-}
377                         {+} {
378                                 if {[regexp {^\+([<>]{7} |={7})} $line _g op]} {
379                                         set is_conflict_diff 1
380                                         set tags d$op
381                                 } else {
382                                         set tags d_+
383                                 }
384                         }
385                         default {
386                                 puts "error: Unhandled 2 way diff marker: {$op}"
387                                 set tags {}
388                         }
389                         }
390                 }
391                 $ui_diff insert end $line $tags
392                 if {[string index $line end] eq "\r"} {
393                         $ui_diff tag add d_cr {end - 2c}
394                 }
395                 $ui_diff insert end "\n" $tags
396         }
397         $ui_diff conf -state disabled
398
399         if {[eof $fd]} {
400                 close $fd
401
402                 if {$current_diff_queue ne {}} {
403                         advance_diff_queue $cont_info
404                         return
405                 }
406
407                 set diff_active 0
408                 unlock_index
409                 set scroll_pos [lindex $cont_info 0]
410                 if {$scroll_pos ne {}} {
411                         update
412                         $ui_diff yview moveto $scroll_pos
413                 }
414                 ui_ready
415
416                 if {[$ui_diff index end] eq {2.0}} {
417                         handle_empty_diff
418                 }
419                 set callback [lindex $cont_info 1]
420                 if {$callback ne {}} {
421                         eval $callback
422                 }
423         }
424 }
425
426 proc apply_hunk {x y} {
427         global current_diff_path current_diff_header current_diff_side
428         global ui_diff ui_index file_states
429
430         if {$current_diff_path eq {} || $current_diff_header eq {}} return
431         if {![lock_index apply_hunk]} return
432
433         set apply_cmd {apply --cached --whitespace=nowarn}
434         set mi [lindex $file_states($current_diff_path) 0]
435         if {$current_diff_side eq $ui_index} {
436                 set failed_msg [mc "Failed to unstage selected hunk."]
437                 lappend apply_cmd --reverse
438                 if {[string index $mi 0] ne {M}} {
439                         unlock_index
440                         return
441                 }
442         } else {
443                 set failed_msg [mc "Failed to stage selected hunk."]
444                 if {[string index $mi 1] ne {M}} {
445                         unlock_index
446                         return
447                 }
448         }
449
450         set s_lno [lindex [split [$ui_diff index @$x,$y] .] 0]
451         set s_lno [$ui_diff search -backwards -regexp ^@@ $s_lno.0 0.0]
452         if {$s_lno eq {}} {
453                 unlock_index
454                 return
455         }
456
457         set e_lno [$ui_diff search -forwards -regexp ^@@ "$s_lno + 1 lines" end]
458         if {$e_lno eq {}} {
459                 set e_lno end
460         }
461
462         if {[catch {
463                 set enc [get_path_encoding $current_diff_path]
464                 set p [eval git_write $apply_cmd]
465                 fconfigure $p -translation binary -encoding $enc
466                 puts -nonewline $p $current_diff_header
467                 puts -nonewline $p [$ui_diff get $s_lno $e_lno]
468                 close $p} err]} {
469                 error_popup [append $failed_msg "\n\n$err"]
470                 unlock_index
471                 return
472         }
473
474         $ui_diff conf -state normal
475         $ui_diff delete $s_lno $e_lno
476         $ui_diff conf -state disabled
477
478         if {[$ui_diff get 1.0 end] eq "\n"} {
479                 set o _
480         } else {
481                 set o ?
482         }
483
484         if {$current_diff_side eq $ui_index} {
485                 set mi ${o}M
486         } elseif {[string index $mi 0] eq {_}} {
487                 set mi M$o
488         } else {
489                 set mi ?$o
490         }
491         unlock_index
492         display_file $current_diff_path $mi
493         # This should trigger shift to the next changed file
494         if {$o eq {_}} {
495                 reshow_diff
496         }
497 }
498
499 proc apply_line {x y} {
500         global current_diff_path current_diff_header current_diff_side
501         global ui_diff ui_index file_states
502
503         if {$current_diff_path eq {} || $current_diff_header eq {}} return
504         if {![lock_index apply_hunk]} return
505
506         set apply_cmd {apply --cached --whitespace=nowarn}
507         set mi [lindex $file_states($current_diff_path) 0]
508         if {$current_diff_side eq $ui_index} {
509                 set failed_msg [mc "Failed to unstage selected line."]
510                 set to_context {+}
511                 lappend apply_cmd --reverse
512                 if {[string index $mi 0] ne {M}} {
513                         unlock_index
514                         return
515                 }
516         } else {
517                 set failed_msg [mc "Failed to stage selected line."]
518                 set to_context {-}
519                 if {[string index $mi 1] ne {M}} {
520                         unlock_index
521                         return
522                 }
523         }
524
525         set the_l [$ui_diff index @$x,$y]
526
527         # operate only on change lines
528         set c1 [$ui_diff get "$the_l linestart"]
529         if {$c1 ne {+} && $c1 ne {-}} {
530                 unlock_index
531                 return
532         }
533         set sign $c1
534
535         set i_l [$ui_diff search -backwards -regexp ^@@ $the_l 0.0]
536         if {$i_l eq {}} {
537                 unlock_index
538                 return
539         }
540         # $i_l is now at the beginning of a line
541
542         # pick start line number from hunk header
543         set hh [$ui_diff get $i_l "$i_l + 1 lines"]
544         set hh [lindex [split $hh ,] 0]
545         set hln [lindex [split $hh -] 1]
546
547         # There is a special situation to take care of. Consider this hunk:
548         #
549         #    @@ -10,4 +10,4 @@
550         #     context before
551         #    -old 1
552         #    -old 2
553         #    +new 1
554         #    +new 2
555         #     context after
556         #
557         # We used to keep the context lines in the order they appear in the
558         # hunk. But then it is not possible to correctly stage only
559         # "-old 1" and "+new 1" - it would result in this staged text:
560         #
561         #    context before
562         #    old 2
563         #    new 1
564         #    context after
565         #
566         # (By symmetry it is not possible to *un*stage "old 2" and "new 2".)
567         #
568         # We resolve the problem by introducing an asymmetry, namely, when
569         # a "+" line is *staged*, it is moved in front of the context lines
570         # that are generated from the "-" lines that are immediately before
571         # the "+" block. That is, we construct this patch:
572         #
573         #    @@ -10,4 +10,5 @@
574         #     context before
575         #    +new 1
576         #     old 1
577         #     old 2
578         #     context after
579         #
580         # But we do *not* treat "-" lines that are *un*staged in a special
581         # way.
582         #
583         # With this asymmetry it is possible to stage the change
584         # "old 1" -> "new 1" directly, and to stage the change
585         # "old 2" -> "new 2" by first staging the entire hunk and
586         # then unstaging the change "old 1" -> "new 1".
587
588         # This is non-empty if and only if we are _staging_ changes;
589         # then it accumulates the consecutive "-" lines (after converting
590         # them to context lines) in order to be moved after the "+" change
591         # line.
592         set pre_context {}
593
594         set n 0
595         set i_l [$ui_diff index "$i_l + 1 lines"]
596         set patch {}
597         while {[$ui_diff compare $i_l < "end - 1 chars"] &&
598                [$ui_diff get $i_l "$i_l + 2 chars"] ne {@@}} {
599                 set next_l [$ui_diff index "$i_l + 1 lines"]
600                 set c1 [$ui_diff get $i_l]
601                 if {[$ui_diff compare $i_l <= $the_l] &&
602                     [$ui_diff compare $the_l < $next_l]} {
603                         # the line to stage/unstage
604                         set ln [$ui_diff get $i_l $next_l]
605                         if {$c1 eq {-}} {
606                                 set n [expr $n+1]
607                                 set patch "$patch$pre_context$ln"
608                         } else {
609                                 set patch "$patch$ln$pre_context"
610                         }
611                         set pre_context {}
612                 } elseif {$c1 ne {-} && $c1 ne {+}} {
613                         # context line
614                         set ln [$ui_diff get $i_l $next_l]
615                         set patch "$patch$pre_context$ln"
616                         set n [expr $n+1]
617                         set pre_context {}
618                 } elseif {$c1 eq $to_context} {
619                         # turn change line into context line
620                         set ln [$ui_diff get "$i_l + 1 chars" $next_l]
621                         if {$c1 eq {-}} {
622                                 set pre_context "$pre_context $ln"
623                         } else {
624                                 set patch "$patch $ln"
625                         }
626                         set n [expr $n+1]
627                 }
628                 set i_l $next_l
629         }
630         set patch "@@ -$hln,$n +$hln,[eval expr $n $sign 1] @@\n$patch"
631
632         if {[catch {
633                 set enc [get_path_encoding $current_diff_path]
634                 set p [eval git_write $apply_cmd]
635                 fconfigure $p -translation binary -encoding $enc
636                 puts -nonewline $p $current_diff_header
637                 puts -nonewline $p $patch
638                 close $p} err]} {
639                 error_popup [append $failed_msg "\n\n$err"]
640         }
641
642         unlock_index
643 }