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 enc [gitattr $path encoding UTF-8]
 168                                         set fd [open $path r]
 169                                         fconfigure $fd \
 170                                                 -eofchar {} \
 171                                                 -encoding [tcl_encoding $enc]
 172                                         set content [read $fd $max_sz]
 173                                         close $fd
 174                                         set sz [file size $path]
 175                                 }
 176                                 default {
 177                                         error "'$type' not supported"
 178                                 }
 179                                 }
 180                         } err ]} {
 181                         set diff_active 0
 182                         unlock_index
 183                         ui_status [mc "Unable to display %s" [escape_path $path]]
 184                         error_popup [strcat [mc "Error loading file:"] "\n\n$err"]
 185                         return
 186                 }
 187                 $ui_diff conf -state normal
 188                 if {$type eq {submodule}} {
 189                         $ui_diff insert end [append \
 190                                 "* " \
 191                                 [mc "Git Repository (subproject)"] \
 192                                 "\n"] d_@
 193                 } elseif {![catch {set type [exec file $path]}]} {
 194                         set n [string length $path]
 195                         if {[string equal -length $n $path $type]} {
 196                                 set type [string range $type $n end]
 197                                 regsub {^:?\s*} $type {} type
 198                         }
 199                         $ui_diff insert end "* $type\n" d_@
 200                 }
 201                 if {[string first "\0" $content] != -1} {
 202                         $ui_diff insert end \
 203                                 [mc "* Binary file (not showing content)."] \
 204                                 d_@
 205                 } else {
 206                         if {$sz > $max_sz} {
 207                                 $ui_diff insert end \
 208 "* Untracked file is $sz bytes.
 209 * Showing only first $max_sz bytes.
 210 " d_@
 211                         }
 212                         $ui_diff insert end $content
 213                         if {$sz > $max_sz} {
 214                                 $ui_diff insert end "
 215 * Untracked file clipped here by [appname].
 216 * To see the entire file, use an external editor.
 217 " d_@
 218                         }
 219                 }
 220                 $ui_diff conf -state disabled
 221                 set diff_active 0
 222                 unlock_index
 223                 if {$scroll_pos ne {}} {
 224                         update
 225                         $ui_diff yview moveto $scroll_pos
 226                 }
 227                 ui_ready
 228                 return
 229         }
 230 }
 231
 232 proc start_show_diff {scroll_pos {add_opts {}}} {
 233         global file_states file_lists
 234         global is_3way_diff diff_active repo_config
 235         global ui_diff ui_index ui_workdir
 236         global current_diff_path current_diff_side current_diff_header
 237
 238         set path $current_diff_path
 239         set w $current_diff_side
 240
 241         set s $file_states($path)
 242         set m [lindex $s 0]
 243         set is_3way_diff 0
 244         set diff_active 1
 245         set current_diff_header {}
 246
 247         set cmd [list]
 248         if {$w eq $ui_index} {
 249                 lappend cmd diff-index
 250                 lappend cmd --cached
 251         } elseif {$w eq $ui_workdir} {
 252                 if {[string first {U} $m] >= 0} {
 253                         lappend cmd diff
 254                 } else {
 255                         lappend cmd diff-files
 256                 }
 257         }
 258
 259         lappend cmd -p
 260         lappend cmd --no-color
 261         if {$repo_config(gui.diffcontext) >= 1} {
 262                 lappend cmd "-U$repo_config(gui.diffcontext)"
 263         }
 264         if {$w eq $ui_index} {
 265                 lappend cmd [PARENT]
 266         }
 267         if {$add_opts ne {}} {
 268                 eval lappend cmd $add_opts
 269         } else {
 270                 lappend cmd --
 271                 lappend cmd $path
 272         }
 273
 274         if {[catch {set fd [eval git_read --nice $cmd]} err]} {
 275                 set diff_active 0
 276                 unlock_index
 277                 ui_status [mc "Unable to display %s" [escape_path $path]]
 278                 error_popup [strcat [mc "Error loading diff:"] "\n\n$err"]
 279                 return
 280         }
 281
 282         set ::current_diff_inheader 1
 283         fconfigure $fd \
 284                 -blocking 0 \
 285                 -encoding [tcl_encoding [gitattr $path encoding UTF-8]] \
 286                 -translation lf
 287         fileevent $fd readable [list read_diff $fd $scroll_pos]
 288 }
 289
 290 proc read_diff {fd scroll_pos} {
 291         global ui_diff diff_active
 292         global is_3way_diff current_diff_header
 293         global current_diff_queue
 294
 295         $ui_diff conf -state normal
 296         while {[gets $fd line] >= 0} {
 297                 # -- Cleanup uninteresting diff header lines.
 298                 #
 299                 if {$::current_diff_inheader} {
 300                         if {   [string match {diff --git *}      $line]
 301                             || [string match {diff --cc *}       $line]
 302                             || [string match {diff --combined *} $line]
 303                             || [string match {--- *}             $line]
 304                             || [string match {+++ *}             $line]} {
 305                                 append current_diff_header $line "\n"
 306                                 continue
 307                         }
 308                 }
 309                 if {[string match {index *} $line]} continue
 310                 if {$line eq {deleted file mode 120000}} {
 311                         set line "deleted symlink"
 312                 }
 313                 set ::current_diff_inheader 0
 314
 315                 # -- Automatically detect if this is a 3 way diff.
 316                 #
 317                 if {[string match {@@@ *} $line]} {set is_3way_diff 1}
 318
 319                 if {[string match {mode *} $line]
 320                         || [string match {new file *} $line]
 321                         || [regexp {^(old|new) mode *} $line]
 322                         || [string match {deleted file *} $line]
 323                         || [string match {deleted symlink} $line]
 324                         || [string match {Binary files * and * differ} $line]
 325                         || $line eq {\ No newline at end of file}
 326                         || [regexp {^\* Unmerged path } $line]} {
 327                         set tags {}
 328                 } elseif {$is_3way_diff} {
 329                         set op [string range $line 0 1]
 330                         switch -- $op {
 331                         {  } {set tags {}}
 332                         {@@} {set tags d_@}
 333                         { +} {set tags d_s+}
 334                         { -} {set tags d_s-}
 335                         {+ } {set tags d_+s}
 336                         {- } {set tags d_-s}
 337                         {--} {set tags d_--}
 338                         {++} {
 339                                 if {[regexp {^\+\+([<>]{7} |={7})} $line _g op]} {
 340                                         set line [string replace $line 0 1 {  }]
 341                                         set tags d$op
 342                                 } else {
 343                                         set tags d_++
 344                                 }
 345                         }
 346                         default {
 347                                 puts "error: Unhandled 3 way diff marker: {$op}"
 348                                 set tags {}
 349                         }
 350                         }
 351                 } else {
 352                         set op [string index $line 0]
 353                         switch -- $op {
 354                         { } {set tags {}}
 355                         {@} {set tags d_@}
 356                         {-} {set tags d_-}
 357                         {+} {
 358                                 if {[regexp {^\+([<>]{7} |={7})} $line _g op]} {
 359                                         set line [string replace $line 0 0 { }]
 360                                         set tags d$op
 361                                 } else {
 362                                         set tags d_+
 363                                 }
 364                         }
 365                         default {
 366                                 puts "error: Unhandled 2 way diff marker: {$op}"
 367                                 set tags {}
 368                         }
 369                         }
 370                 }
 371                 $ui_diff insert end $line $tags
 372                 if {[string index $line end] eq "\r"} {
 373                         $ui_diff tag add d_cr {end - 2c}
 374                 }
 375                 $ui_diff insert end "\n" $tags
 376         }
 377         $ui_diff conf -state disabled
 378
 379         if {[eof $fd]} {
 380                 close $fd
 381
 382                 if {$current_diff_queue ne {}} {
 383                         advance_diff_queue $scroll_pos
 384                         return
 385                 }
 386
 387                 set diff_active 0
 388                 unlock_index
 389                 if {$scroll_pos ne {}} {
 390                         update
 391                         $ui_diff yview moveto $scroll_pos
 392                 }
 393                 ui_ready
 394
 395                 if {[$ui_diff index end] eq {2.0}} {
 396                         handle_empty_diff
 397                 }
 398         }
 399 }
 400
 401 proc apply_hunk {x y} {
 402         global current_diff_path current_diff_header current_diff_side
 403         global ui_diff ui_index file_states
 404
 405         if {$current_diff_path eq {} || $current_diff_header eq {}} return
 406         if {![lock_index apply_hunk]} return
 407
 408         set apply_cmd {apply --cached --whitespace=nowarn}
 409         set mi [lindex $file_states($current_diff_path) 0]
 410         if {$current_diff_side eq $ui_index} {
 411                 set failed_msg [mc "Failed to unstage selected hunk."]
 412                 lappend apply_cmd --reverse
 413                 if {[string index $mi 0] ne {M}} {
 414                         unlock_index
 415                         return
 416                 }
 417         } else {
 418                 set failed_msg [mc "Failed to stage selected hunk."]
 419                 if {[string index $mi 1] ne {M}} {
 420                         unlock_index
 421                         return
 422                 }
 423         }
 424
 425         set s_lno [lindex [split [$ui_diff index @$x,$y] .] 0]
 426         set s_lno [$ui_diff search -backwards -regexp ^@@ $s_lno.0 0.0]
 427         if {$s_lno eq {}} {
 428                 unlock_index
 429                 return
 430         }
 431
 432         set e_lno [$ui_diff search -forwards -regexp ^@@ "$s_lno + 1 lines" end]
 433         if {$e_lno eq {}} {
 434                 set e_lno end
 435         }
 436
 437         if {[catch {
 438                 set p [eval git_write $apply_cmd]
 439                 fconfigure $p -translation binary -encoding binary
 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 p [eval git_write $apply_cmd]
 608                 fconfigure $p -translation binary -encoding binary
 609                 puts -nonewline $p $current_diff_header
 610                 puts -nonewline $p $patch
 611                 close $p} err]} {
 612                 error_popup [append $failed_msg "\n\n$err"]
 613         }
 614
 615         unlock_index
 616 }