git-gui: Add a menu of available encodings.
[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 {} {
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 $p {} {[^O]}]} {
33                         next_diff
34                 } else {
35                         clear_diff
36                 }
37         } else {
38                 set save_pos [lindex [$ui_diff yview] 0]
39                 show_diff $p $current_diff_side {} $save_pos
40         }
41 }
42
43 proc handle_empty_diff {} {
44         global current_diff_path file_states file_lists
45
46         set path $current_diff_path
47         set s $file_states($path)
48         if {[lindex $s 0] ne {_M}} return
49
50         info_popup [mc "No differences detected.
51
52 %s has no changes.
53
54 The modification date of this file was updated by another application, but the content within the file was not changed.
55
56 A rescan will be automatically started to find other files which may have the same state." [short_path $path]]
57
58         clear_diff
59         display_file $path __
60         rescan ui_ready 0
61 }
62
63 proc show_diff {path w {lno {}} {scroll_pos {}}} {
64         global file_states file_lists
65         global is_3way_diff diff_active repo_config
66         global ui_diff ui_index ui_workdir
67         global current_diff_path current_diff_side current_diff_header
68         global current_diff_queue
69
70         if {$diff_active || ![lock_index read]} return
71
72         clear_diff
73         if {$lno == {}} {
74                 set lno [lsearch -sorted -exact $file_lists($w) $path]
75                 if {$lno >= 0} {
76                         incr lno
77                 }
78         }
79         if {$lno >= 1} {
80                 $w tag add in_diff $lno.0 [expr {$lno + 1}].0
81                 $w see $lno.0
82         }
83
84         set s $file_states($path)
85         set m [lindex $s 0]
86         set current_diff_path $path
87         set current_diff_side $w
88         set current_diff_queue {}
89         ui_status [mc "Loading diff of %s..." [escape_path $path]]
90
91         if {[string first {U} $m] >= 0} {
92                 merge_load_stages $path [list show_unmerged_diff $scroll_pos]
93         } elseif {$m eq {_O}} {
94                 show_other_diff $path $w $m $scroll_pos
95         } else {
96                 start_show_diff $scroll_pos
97         }
98 }
99
100 proc show_unmerged_diff {scroll_pos} {
101         global current_diff_path current_diff_side
102         global merge_stages ui_diff
103         global current_diff_queue
104
105         if {$merge_stages(2) eq {}} {
106                 lappend current_diff_queue \
107                         [list "LOCAL: deleted\nREMOTE:\n" d======= \
108                             [list ":1:$current_diff_path" ":3:$current_diff_path"]]
109         } elseif {$merge_stages(3) eq {}} {
110                 lappend current_diff_queue \
111                         [list "REMOTE: deleted\nLOCAL:\n" d======= \
112                             [list ":1:$current_diff_path" ":2:$current_diff_path"]]
113         } elseif {[lindex $merge_stages(1) 0] eq {120000}
114                 || [lindex $merge_stages(2) 0] eq {120000}
115                 || [lindex $merge_stages(3) 0] eq {120000}} {
116                 lappend current_diff_queue \
117                         [list "LOCAL:\n" d======= \
118                             [list ":1:$current_diff_path" ":2:$current_diff_path"]]
119                 lappend current_diff_queue \
120                         [list "REMOTE:\n" d======= \
121                             [list ":1:$current_diff_path" ":3:$current_diff_path"]]
122         } else {
123                 start_show_diff $scroll_pos
124                 return
125         }
126
127         advance_diff_queue $scroll_pos
128 }
129
130 proc advance_diff_queue {scroll_pos} {
131         global current_diff_queue ui_diff
132
133         set item [lindex $current_diff_queue 0]
134         set current_diff_queue [lrange $current_diff_queue 1 end]
135
136         $ui_diff conf -state normal
137         $ui_diff insert end [lindex $item 0] [lindex $item 1]
138         $ui_diff conf -state disabled
139
140         start_show_diff $scroll_pos [lindex $item 2]
141 }
142
143 proc show_other_diff {path w m scroll_pos} {
144         global file_states file_lists
145         global is_3way_diff diff_active repo_config
146         global ui_diff ui_index ui_workdir
147         global current_diff_path current_diff_side current_diff_header
148
149         # - Git won't give us the diff, there's nothing to compare to!
150         #
151         if {$m eq {_O}} {
152                 set max_sz [expr {128 * 1024}]
153                 set type unknown
154                 if {[catch {
155                                 set type [file type $path]
156                                 switch -- $type {
157                                 directory {
158                                         set type submodule
159                                         set content {}
160                                         set sz 0
161                                 }
162                                 link {
163                                         set content [file readlink $path]
164                                         set sz [string length $content]
165                                 }
166                                 file {
167                                         set fd [open $path r]
168                                         fconfigure $fd \
169                                                 -eofchar {} \
170                                                 -encoding [get_path_encoding $path]
171                                         set content [read $fd $max_sz]
172                                         close $fd
173                                         set sz [file size $path]
174                                 }
175                                 default {
176                                         error "'$type' not supported"
177                                 }
178                                 }
179                         } err ]} {
180                         set diff_active 0
181                         unlock_index
182                         ui_status [mc "Unable to display %s" [escape_path $path]]
183                         error_popup [strcat [mc "Error loading file:"] "\n\n$err"]
184                         return
185                 }
186                 $ui_diff conf -state normal
187                 if {$type eq {submodule}} {
188                         $ui_diff insert end [append \
189                                 "* " \
190                                 [mc "Git Repository (subproject)"] \
191                                 "\n"] d_@
192                 } elseif {![catch {set type [exec file $path]}]} {
193                         set n [string length $path]
194                         if {[string equal -length $n $path $type]} {
195                                 set type [string range $type $n end]
196                                 regsub {^:?\s*} $type {} type
197                         }
198                         $ui_diff insert end "* $type\n" d_@
199                 }
200                 if {[string first "\0" $content] != -1} {
201                         $ui_diff insert end \
202                                 [mc "* Binary file (not showing content)."] \
203                                 d_@
204                 } else {
205                         if {$sz > $max_sz} {
206                                 $ui_diff insert end \
207 "* Untracked file is $sz bytes.
208 * Showing only first $max_sz bytes.
209 " d_@
210                         }
211                         $ui_diff insert end $content
212                         if {$sz > $max_sz} {
213                                 $ui_diff insert end "
214 * Untracked file clipped here by [appname].
215 * To see the entire file, use an external editor.
216 " d_@
217                         }
218                 }
219                 $ui_diff conf -state disabled
220                 set diff_active 0
221                 unlock_index
222                 if {$scroll_pos ne {}} {
223                         update
224                         $ui_diff yview moveto $scroll_pos
225                 }
226                 ui_ready
227                 return
228         }
229 }
230
231 proc start_show_diff {scroll_pos {add_opts {}}} {
232         global file_states file_lists
233         global is_3way_diff diff_active repo_config
234         global ui_diff ui_index ui_workdir
235         global current_diff_path current_diff_side current_diff_header
236
237         set path $current_diff_path
238         set w $current_diff_side
239
240         set s $file_states($path)
241         set m [lindex $s 0]
242         set is_3way_diff 0
243         set diff_active 1
244         set current_diff_header {}
245
246         set cmd [list]
247         if {$w eq $ui_index} {
248                 lappend cmd diff-index
249                 lappend cmd --cached
250         } elseif {$w eq $ui_workdir} {
251                 if {[string first {U} $m] >= 0} {
252                         lappend cmd diff
253                 } else {
254                         lappend cmd diff-files
255                 }
256         }
257
258         lappend cmd -p
259         lappend cmd --no-color
260         if {$repo_config(gui.diffcontext) >= 1} {
261                 lappend cmd "-U$repo_config(gui.diffcontext)"
262         }
263         if {$w eq $ui_index} {
264                 lappend cmd [PARENT]
265         }
266         if {$add_opts ne {}} {
267                 eval lappend cmd $add_opts
268         } else {
269                 lappend cmd --
270                 lappend cmd $path
271         }
272
273         if {[catch {set fd [eval git_read --nice $cmd]} err]} {
274                 set diff_active 0
275                 unlock_index
276                 ui_status [mc "Unable to display %s" [escape_path $path]]
277                 error_popup [strcat [mc "Error loading diff:"] "\n\n$err"]
278                 return
279         }
280
281         set ::current_diff_inheader 1
282         fconfigure $fd \
283                 -blocking 0 \
284                 -encoding [get_path_encoding $path] \
285                 -translation lf
286         fileevent $fd readable [list read_diff $fd $scroll_pos]
287 }
288
289 proc read_diff {fd scroll_pos} {
290         global ui_diff diff_active
291         global is_3way_diff current_diff_header
292         global current_diff_queue
293
294         $ui_diff conf -state normal
295         while {[gets $fd line] >= 0} {
296                 # -- Cleanup uninteresting diff header lines.
297                 #
298                 if {$::current_diff_inheader} {
299                         if {   [string match {diff --git *}      $line]
300                             || [string match {diff --cc *}       $line]
301                             || [string match {diff --combined *} $line]
302                             || [string match {--- *}             $line]
303                             || [string match {+++ *}             $line]} {
304                                 append current_diff_header $line "\n"
305                                 continue
306                         }
307                 }
308                 if {[string match {index *} $line]} continue
309                 if {$line eq {deleted file mode 120000}} {
310                         set line "deleted symlink"
311                 }
312                 set ::current_diff_inheader 0
313
314                 # -- Automatically detect if this is a 3 way diff.
315                 #
316                 if {[string match {@@@ *} $line]} {set is_3way_diff 1}
317
318                 if {[string match {mode *} $line]
319                         || [string match {new file *} $line]
320                         || [regexp {^(old|new) mode *} $line]
321                         || [string match {deleted file *} $line]
322                         || [string match {deleted symlink} $line]
323                         || [string match {Binary files * and * differ} $line]
324                         || $line eq {\ No newline at end of file}
325                         || [regexp {^\* Unmerged path } $line]} {
326                         set tags {}
327                 } elseif {$is_3way_diff} {
328                         set op [string range $line 0 1]
329                         switch -- $op {
330                         {  } {set tags {}}
331                         {@@} {set tags d_@}
332                         { +} {set tags d_s+}
333                         { -} {set tags d_s-}
334                         {+ } {set tags d_+s}
335                         {- } {set tags d_-s}
336                         {--} {set tags d_--}
337                         {++} {
338                                 if {[regexp {^\+\+([<>]{7} |={7})} $line _g op]} {
339                                         set line [string replace $line 0 1 {  }]
340                                         set tags d$op
341                                 } else {
342                                         set tags d_++
343                                 }
344                         }
345                         default {
346                                 puts "error: Unhandled 3 way diff marker: {$op}"
347                                 set tags {}
348                         }
349                         }
350                 } else {
351                         set op [string index $line 0]
352                         switch -- $op {
353                         { } {set tags {}}
354                         {@} {set tags d_@}
355                         {-} {set tags d_-}
356                         {+} {
357                                 if {[regexp {^\+([<>]{7} |={7})} $line _g op]} {
358                                         set line [string replace $line 0 0 { }]
359                                         set tags d$op
360                                 } else {
361                                         set tags d_+
362                                 }
363                         }
364                         default {
365                                 puts "error: Unhandled 2 way diff marker: {$op}"
366                                 set tags {}
367                         }
368                         }
369                 }
370                 $ui_diff insert end $line $tags
371                 if {[string index $line end] eq "\r"} {
372                         $ui_diff tag add d_cr {end - 2c}
373                 }
374                 $ui_diff insert end "\n" $tags
375         }
376         $ui_diff conf -state disabled
377
378         if {[eof $fd]} {
379                 close $fd
380
381                 if {$current_diff_queue ne {}} {
382                         advance_diff_queue $scroll_pos
383                         return
384                 }
385
386                 set diff_active 0
387                 unlock_index
388                 if {$scroll_pos ne {}} {
389                         update
390                         $ui_diff yview moveto $scroll_pos
391                 }
392                 ui_ready
393
394                 if {[$ui_diff index end] eq {2.0}} {
395                         handle_empty_diff
396                 }
397         }
398 }
399
400 proc apply_hunk {x y} {
401         global current_diff_path current_diff_header current_diff_side
402         global ui_diff ui_index file_states
403
404         if {$current_diff_path eq {} || $current_diff_header eq {}} return
405         if {![lock_index apply_hunk]} return
406
407         set apply_cmd {apply --cached --whitespace=nowarn}
408         set mi [lindex $file_states($current_diff_path) 0]
409         if {$current_diff_side eq $ui_index} {
410                 set failed_msg [mc "Failed to unstage selected hunk."]
411                 lappend apply_cmd --reverse
412                 if {[string index $mi 0] ne {M}} {
413                         unlock_index
414                         return
415                 }
416         } else {
417                 set failed_msg [mc "Failed to stage selected hunk."]
418                 if {[string index $mi 1] ne {M}} {
419                         unlock_index
420                         return
421                 }
422         }
423
424         set s_lno [lindex [split [$ui_diff index @$x,$y] .] 0]
425         set s_lno [$ui_diff search -backwards -regexp ^@@ $s_lno.0 0.0]
426         if {$s_lno eq {}} {
427                 unlock_index
428                 return
429         }
430
431         set e_lno [$ui_diff search -forwards -regexp ^@@ "$s_lno + 1 lines" end]
432         if {$e_lno eq {}} {
433                 set e_lno end
434         }
435
436         if {[catch {
437                 set enc [get_path_encoding $current_diff_path]
438                 set p [eval git_write $apply_cmd]
439                 fconfigure $p -translation binary -encoding $enc
440                 puts -nonewline $p $current_diff_header
441                 puts -nonewline $p [$ui_diff get $s_lno $e_lno]
442                 close $p} err]} {
443                 error_popup [append $failed_msg "\n\n$err"]
444                 unlock_index
445                 return
446         }
447
448         $ui_diff conf -state normal
449         $ui_diff delete $s_lno $e_lno
450         $ui_diff conf -state disabled
451
452         if {[$ui_diff get 1.0 end] eq "\n"} {
453                 set o _
454         } else {
455                 set o ?
456         }
457
458         if {$current_diff_side eq $ui_index} {
459                 set mi ${o}M
460         } elseif {[string index $mi 0] eq {_}} {
461                 set mi M$o
462         } else {
463                 set mi ?$o
464         }
465         unlock_index
466         display_file $current_diff_path $mi
467         # This should trigger shift to the next changed file
468         if {$o eq {_}} {
469                 reshow_diff
470         }
471 }
472
473 proc apply_line {x y} {
474         global current_diff_path current_diff_header current_diff_side
475         global ui_diff ui_index file_states
476
477         if {$current_diff_path eq {} || $current_diff_header eq {}} return
478         if {![lock_index apply_hunk]} return
479
480         set apply_cmd {apply --cached --whitespace=nowarn}
481         set mi [lindex $file_states($current_diff_path) 0]
482         if {$current_diff_side eq $ui_index} {
483                 set failed_msg [mc "Failed to unstage selected line."]
484                 set to_context {+}
485                 lappend apply_cmd --reverse
486                 if {[string index $mi 0] ne {M}} {
487                         unlock_index
488                         return
489                 }
490         } else {
491                 set failed_msg [mc "Failed to stage selected line."]
492                 set to_context {-}
493                 if {[string index $mi 1] ne {M}} {
494                         unlock_index
495                         return
496                 }
497         }
498
499         set the_l [$ui_diff index @$x,$y]
500
501         # operate only on change lines
502         set c1 [$ui_diff get "$the_l linestart"]
503         if {$c1 ne {+} && $c1 ne {-}} {
504                 unlock_index
505                 return
506         }
507         set sign $c1
508
509         set i_l [$ui_diff search -backwards -regexp ^@@ $the_l 0.0]
510         if {$i_l eq {}} {
511                 unlock_index
512                 return
513         }
514         # $i_l is now at the beginning of a line
515
516         # pick start line number from hunk header
517         set hh [$ui_diff get $i_l "$i_l + 1 lines"]
518         set hh [lindex [split $hh ,] 0]
519         set hln [lindex [split $hh -] 1]
520
521         # There is a special situation to take care of. Consider this hunk:
522         #
523         #    @@ -10,4 +10,4 @@
524         #     context before
525         #    -old 1
526         #    -old 2
527         #    +new 1
528         #    +new 2
529         #     context after
530         #
531         # We used to keep the context lines in the order they appear in the
532         # hunk. But then it is not possible to correctly stage only
533         # "-old 1" and "+new 1" - it would result in this staged text:
534         #
535         #    context before
536         #    old 2
537         #    new 1
538         #    context after
539         #
540         # (By symmetry it is not possible to *un*stage "old 2" and "new 2".)
541         #
542         # We resolve the problem by introducing an asymmetry, namely, when
543         # a "+" line is *staged*, it is moved in front of the context lines
544         # that are generated from the "-" lines that are immediately before
545         # the "+" block. That is, we construct this patch:
546         #
547         #    @@ -10,4 +10,5 @@
548         #     context before
549         #    +new 1
550         #     old 1
551         #     old 2
552         #     context after
553         #
554         # But we do *not* treat "-" lines that are *un*staged in a special
555         # way.
556         #
557         # With this asymmetry it is possible to stage the change
558         # "old 1" -> "new 1" directly, and to stage the change
559         # "old 2" -> "new 2" by first staging the entire hunk and
560         # then unstaging the change "old 1" -> "new 1".
561
562         # This is non-empty if and only if we are _staging_ changes;
563         # then it accumulates the consecutive "-" lines (after converting
564         # them to context lines) in order to be moved after the "+" change
565         # line.
566         set pre_context {}
567
568         set n 0
569         set i_l [$ui_diff index "$i_l + 1 lines"]
570         set patch {}
571         while {[$ui_diff compare $i_l < "end - 1 chars"] &&
572                [$ui_diff get $i_l "$i_l + 2 chars"] ne {@@}} {
573                 set next_l [$ui_diff index "$i_l + 1 lines"]
574                 set c1 [$ui_diff get $i_l]
575                 if {[$ui_diff compare $i_l <= $the_l] &&
576                     [$ui_diff compare $the_l < $next_l]} {
577                         # the line to stage/unstage
578                         set ln [$ui_diff get $i_l $next_l]
579                         if {$c1 eq {-}} {
580                                 set n [expr $n+1]
581                                 set patch "$patch$pre_context$ln"
582                         } else {
583                                 set patch "$patch$ln$pre_context"
584                         }
585                         set pre_context {}
586                 } elseif {$c1 ne {-} && $c1 ne {+}} {
587                         # context line
588                         set ln [$ui_diff get $i_l $next_l]
589                         set patch "$patch$pre_context$ln"
590                         set n [expr $n+1]
591                         set pre_context {}
592                 } elseif {$c1 eq $to_context} {
593                         # turn change line into context line
594                         set ln [$ui_diff get "$i_l + 1 chars" $next_l]
595                         if {$c1 eq {-}} {
596                                 set pre_context "$pre_context $ln"
597                         } else {
598                                 set patch "$patch $ln"
599                         }
600                         set n [expr $n+1]
601                 }
602                 set i_l $next_l
603         }
604         set patch "@@ -$hln,$n +$hln,[eval expr $n $sign 1] @@\n$patch"
605
606         if {[catch {
607                 set enc [get_path_encoding $current_diff_path]
608                 set p [eval git_write $apply_cmd]
609                 fconfigure $p -translation binary -encoding $enc
610                 puts -nonewline $p $current_diff_header
611                 puts -nonewline $p $patch
612                 close $p} err]} {
613                 error_popup [append $failed_msg "\n\n$err"]
614         }
615
616         unlock_index
617 }