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 {} $save_pos
  40         }
  41 }
  42
  43 proc force_diff_encoding {enc} {
  44         global current_diff_path
  45
  46         if {$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 $path __
  69         rescan ui_ready 0
  70 }
  71
  72 proc show_diff {path w {lno {}} {scroll_pos {}}} {
  73         global file_states file_lists
  74         global is_3way_diff diff_active repo_config
  75         global ui_diff ui_index ui_workdir
  76         global current_diff_path current_diff_side current_diff_header
  77         global current_diff_queue
  78
  79         if {$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 current_diff_path $path
  96         set current_diff_side $w
  97         set current_diff_queue {}
  98         ui_status [mc "Loading diff of %s..." [escape_path $path]]
  99
 100         if {[string first {U} $m] >= 0} {
 101                 merge_load_stages $path [list show_unmerged_diff $scroll_pos]
 102         } elseif {$m eq {_O}} {
 103                 show_other_diff $path $w $m $scroll_pos
 104         } else {
 105                 start_show_diff $scroll_pos
 106         }
 107 }
 108
 109 proc show_unmerged_diff {scroll_pos} {
 110         global current_diff_path current_diff_side
 111         global merge_stages ui_diff
 112         global current_diff_queue
 113
 114         if {$merge_stages(2) eq {}} {
 115                 lappend current_diff_queue \
 116                         [list "LOCAL: deleted\nREMOTE:\n" d======= \
 117                             [list ":1:$current_diff_path" ":3:$current_diff_path"]]
 118         } elseif {$merge_stages(3) eq {}} {
 119                 lappend current_diff_queue \
 120                         [list "REMOTE: deleted\nLOCAL:\n" d======= \
 121                             [list ":1:$current_diff_path" ":2:$current_diff_path"]]
 122         } elseif {[lindex $merge_stages(1) 0] eq {120000}
 123                 || [lindex $merge_stages(2) 0] eq {120000}
 124                 || [lindex $merge_stages(3) 0] eq {120000}} {
 125                 lappend current_diff_queue \
 126                         [list "LOCAL:\n" d======= \
 127                             [list ":1:$current_diff_path" ":2:$current_diff_path"]]
 128                 lappend current_diff_queue \
 129                         [list "REMOTE:\n" d======= \
 130                             [list ":1:$current_diff_path" ":3:$current_diff_path"]]
 131         } else {
 132                 start_show_diff $scroll_pos
 133                 return
 134         }
 135
 136         advance_diff_queue $scroll_pos
 137 }
 138
 139 proc advance_diff_queue {scroll_pos} {
 140         global current_diff_queue ui_diff
 141
 142         set item [lindex $current_diff_queue 0]
 143         set current_diff_queue [lrange $current_diff_queue 1 end]
 144
 145         $ui_diff conf -state normal
 146         $ui_diff insert end [lindex $item 0] [lindex $item 1]
 147         $ui_diff conf -state disabled
 148
 149         start_show_diff $scroll_pos [lindex $item 2]
 150 }
 151
 152 proc show_other_diff {path w m scroll_pos} {
 153         global file_states file_lists
 154         global is_3way_diff diff_active repo_config
 155         global ui_diff ui_index ui_workdir
 156         global current_diff_path current_diff_side current_diff_header
 157
 158         # - Git won't give us the diff, there's nothing to compare to!
 159         #
 160         if {$m eq {_O}} {
 161                 set max_sz [expr {128 * 1024}]
 162                 set type unknown
 163                 if {[catch {
 164                                 set type [file type $path]
 165                                 switch -- $type {
 166                                 directory {
 167                                         set type submodule
 168                                         set content {}
 169                                         set sz 0
 170                                 }
 171                                 link {
 172                                         set content [file readlink $path]
 173                                         set sz [string length $content]
 174                                 }
 175                                 file {
 176                                         set fd [open $path r]
 177                                         fconfigure $fd \
 178                                                 -eofchar {} \
 179                                                 -encoding [get_path_encoding $path]
 180                                         set content [read $fd $max_sz]
 181                                         close $fd
 182                                         set sz [file size $path]
 183                                 }
 184                                 default {
 185                                         error "'$type' not supported"
 186                                 }
 187                                 }
 188                         } err ]} {
 189                         set diff_active 0
 190                         unlock_index
 191                         ui_status [mc "Unable to display %s" [escape_path $path]]
 192                         error_popup [strcat [mc "Error loading file:"] "\n\n$err"]
 193                         return
 194                 }
 195                 $ui_diff conf -state normal
 196                 if {$type eq {submodule}} {
 197                         $ui_diff insert end [append \
 198                                 "* " \
 199                                 [mc "Git Repository (subproject)"] \
 200                                 "\n"] d_@
 201                 } elseif {![catch {set type [exec file $path]}]} {
 202                         set n [string length $path]
 203                         if {[string equal -length $n $path $type]} {
 204                                 set type [string range $type $n end]
 205                                 regsub {^:?\s*} $type {} type
 206                         }
 207                         $ui_diff insert end "* $type\n" d_@
 208                 }
 209                 if {[string first "\0" $content] != -1} {
 210                         $ui_diff insert end \
 211                                 [mc "* Binary file (not showing content)."] \
 212                                 d_@
 213                 } else {
 214                         if {$sz > $max_sz} {
 215                                 $ui_diff insert end \
 216 "* Untracked file is $sz bytes.
 217 * Showing only first $max_sz bytes.
 218 " d_@
 219                         }
 220                         $ui_diff insert end $content
 221                         if {$sz > $max_sz} {
 222                                 $ui_diff insert end "
 223 * Untracked file clipped here by [appname].
 224 * To see the entire file, use an external editor.
 225 " d_@
 226                         }
 227                 }
 228                 $ui_diff conf -state disabled
 229                 set diff_active 0
 230                 unlock_index
 231                 if {$scroll_pos ne {}} {
 232                         update
 233                         $ui_diff yview moveto $scroll_pos
 234                 }
 235                 ui_ready
 236                 return
 237         }
 238 }
 239
 240 proc start_show_diff {scroll_pos {add_opts {}}} {
 241         global file_states file_lists
 242         global is_3way_diff diff_active repo_config
 243         global ui_diff ui_index ui_workdir
 244         global current_diff_path current_diff_side current_diff_header
 245
 246         set path $current_diff_path
 247         set w $current_diff_side
 248
 249         set s $file_states($path)
 250         set m [lindex $s 0]
 251         set is_3way_diff 0
 252         set diff_active 1
 253         set current_diff_header {}
 254
 255         set cmd [list]
 256         if {$w eq $ui_index} {
 257                 lappend cmd diff-index
 258                 lappend cmd --cached
 259         } elseif {$w eq $ui_workdir} {
 260                 if {[string first {U} $m] >= 0} {
 261                         lappend cmd diff
 262                 } else {
 263                         lappend cmd diff-files
 264                 }
 265         }
 266
 267         lappend cmd -p
 268         lappend cmd --no-color
 269         if {$repo_config(gui.diffcontext) >= 1} {
 270                 lappend cmd "-U$repo_config(gui.diffcontext)"
 271         }
 272         if {$w eq $ui_index} {
 273                 lappend cmd [PARENT]
 274         }
 275         if {$add_opts ne {}} {
 276                 eval lappend cmd $add_opts
 277         } else {
 278                 lappend cmd --
 279                 lappend cmd $path
 280         }
 281
 282         if {[catch {set fd [eval git_read --nice $cmd]} err]} {
 283                 set diff_active 0
 284                 unlock_index
 285                 ui_status [mc "Unable to display %s" [escape_path $path]]
 286                 error_popup [strcat [mc "Error loading diff:"] "\n\n$err"]
 287                 return
 288         }
 289
 290         set ::current_diff_inheader 1
 291         fconfigure $fd \
 292                 -blocking 0 \
 293                 -encoding [get_path_encoding $path] \
 294                 -translation lf
 295         fileevent $fd readable [list read_diff $fd $scroll_pos]
 296 }
 297
 298 proc read_diff {fd scroll_pos} {
 299         global ui_diff diff_active
 300         global is_3way_diff current_diff_header
 301         global current_diff_queue
 302
 303         $ui_diff conf -state normal
 304         while {[gets $fd line] >= 0} {
 305                 # -- Cleanup uninteresting diff header lines.
 306                 #
 307                 if {$::current_diff_inheader} {
 308                         if {   [string match {diff --git *}      $line]
 309                             || [string match {diff --cc *}       $line]
 310                             || [string match {diff --combined *} $line]
 311                             || [string match {--- *}             $line]
 312                             || [string match {+++ *}             $line]} {
 313                                 append current_diff_header $line "\n"
 314                                 continue
 315                         }
 316                 }
 317                 if {[string match {index *} $line]} continue
 318                 if {$line eq {deleted file mode 120000}} {
 319                         set line "deleted symlink"
 320                 }
 321                 set ::current_diff_inheader 0
 322
 323                 # -- Automatically detect if this is a 3 way diff.
 324                 #
 325                 if {[string match {@@@ *} $line]} {set is_3way_diff 1}
 326
 327                 if {[string match {mode *} $line]
 328                         || [string match {new file *} $line]
 329                         || [regexp {^(old|new) mode *} $line]
 330                         || [string match {deleted file *} $line]
 331                         || [string match {deleted symlink} $line]
 332                         || [string match {Binary files * and * differ} $line]
 333                         || $line eq {\ No newline at end of file}
 334                         || [regexp {^\* Unmerged path } $line]} {
 335                         set tags {}
 336                 } elseif {$is_3way_diff} {
 337                         set op [string range $line 0 1]
 338                         switch -- $op {
 339                         {  } {set tags {}}
 340                         {@@} {set tags d_@}
 341                         { +} {set tags d_s+}
 342                         { -} {set tags d_s-}
 343                         {+ } {set tags d_+s}
 344                         {- } {set tags d_-s}
 345                         {--} {set tags d_--}
 346                         {++} {
 347                                 if {[regexp {^\+\+([<>]{7} |={7})} $line _g op]} {
 348                                         set line [string replace $line 0 1 {  }]
 349                                         set tags d$op
 350                                 } else {
 351                                         set tags d_++
 352                                 }
 353                         }
 354                         default {
 355                                 puts "error: Unhandled 3 way diff marker: {$op}"
 356                                 set tags {}
 357                         }
 358                         }
 359                 } else {
 360                         set op [string index $line 0]
 361                         switch -- $op {
 362                         { } {set tags {}}
 363                         {@} {set tags d_@}
 364                         {-} {set tags d_-}
 365                         {+} {
 366                                 if {[regexp {^\+([<>]{7} |={7})} $line _g op]} {
 367                                         set line [string replace $line 0 0 { }]
 368                                         set tags d$op
 369                                 } else {
 370                                         set tags d_+
 371                                 }
 372                         }
 373                         default {
 374                                 puts "error: Unhandled 2 way diff marker: {$op}"
 375                                 set tags {}
 376                         }
 377                         }
 378                 }
 379                 $ui_diff insert end $line $tags
 380                 if {[string index $line end] eq "\r"} {
 381                         $ui_diff tag add d_cr {end - 2c}
 382                 }
 383                 $ui_diff insert end "\n" $tags
 384         }
 385         $ui_diff conf -state disabled
 386
 387         if {[eof $fd]} {
 388                 close $fd
 389
 390                 if {$current_diff_queue ne {}} {
 391                         advance_diff_queue $scroll_pos
 392                         return
 393                 }
 394
 395                 set diff_active 0
 396                 unlock_index
 397                 if {$scroll_pos ne {}} {
 398                         update
 399                         $ui_diff yview moveto $scroll_pos
 400                 }
 401                 ui_ready
 402
 403                 if {[$ui_diff index end] eq {2.0}} {
 404                         handle_empty_diff
 405                 }
 406         }
 407 }
 408
 409 proc apply_hunk {x y} {
 410         global current_diff_path current_diff_header current_diff_side
 411         global ui_diff ui_index file_states
 412
 413         if {$current_diff_path eq {} || $current_diff_header eq {}} return
 414         if {![lock_index apply_hunk]} return
 415
 416         set apply_cmd {apply --cached --whitespace=nowarn}
 417         set mi [lindex $file_states($current_diff_path) 0]
 418         if {$current_diff_side eq $ui_index} {
 419                 set failed_msg [mc "Failed to unstage selected hunk."]
 420                 lappend apply_cmd --reverse
 421                 if {[string index $mi 0] ne {M}} {
 422                         unlock_index
 423                         return
 424                 }
 425         } else {
 426                 set failed_msg [mc "Failed to stage selected hunk."]
 427                 if {[string index $mi 1] ne {M}} {
 428                         unlock_index
 429                         return
 430                 }
 431         }
 432
 433         set s_lno [lindex [split [$ui_diff index @$x,$y] .] 0]
 434         set s_lno [$ui_diff search -backwards -regexp ^@@ $s_lno.0 0.0]
 435         if {$s_lno eq {}} {
 436                 unlock_index
 437                 return
 438         }
 439
 440         set e_lno [$ui_diff search -forwards -regexp ^@@ "$s_lno + 1 lines" end]
 441         if {$e_lno eq {}} {
 442                 set e_lno end
 443         }
 444
 445         if {[catch {
 446                 set enc [get_path_encoding $current_diff_path]
 447                 set p [eval git_write $apply_cmd]
 448                 fconfigure $p -translation binary -encoding $enc
 449                 puts -nonewline $p $current_diff_header
 450                 puts -nonewline $p [$ui_diff get $s_lno $e_lno]
 451                 close $p} err]} {
 452                 error_popup [append $failed_msg "\n\n$err"]
 453                 unlock_index
 454                 return
 455         }
 456
 457         $ui_diff conf -state normal
 458         $ui_diff delete $s_lno $e_lno
 459         $ui_diff conf -state disabled
 460
 461         if {[$ui_diff get 1.0 end] eq "\n"} {
 462                 set o _
 463         } else {
 464                 set o ?
 465         }
 466
 467         if {$current_diff_side eq $ui_index} {
 468                 set mi ${o}M
 469         } elseif {[string index $mi 0] eq {_}} {
 470                 set mi M$o
 471         } else {
 472                 set mi ?$o
 473         }
 474         unlock_index
 475         display_file $current_diff_path $mi
 476         # This should trigger shift to the next changed file
 477         if {$o eq {_}} {
 478                 reshow_diff
 479         }
 480 }
 481
 482 proc apply_line {x y} {
 483         global current_diff_path current_diff_header current_diff_side
 484         global ui_diff ui_index file_states
 485
 486         if {$current_diff_path eq {} || $current_diff_header eq {}} return
 487         if {![lock_index apply_hunk]} return
 488
 489         set apply_cmd {apply --cached --whitespace=nowarn}
 490         set mi [lindex $file_states($current_diff_path) 0]
 491         if {$current_diff_side eq $ui_index} {
 492                 set failed_msg [mc "Failed to unstage selected line."]
 493                 set to_context {+}
 494                 lappend apply_cmd --reverse
 495                 if {[string index $mi 0] ne {M}} {
 496                         unlock_index
 497                         return
 498                 }
 499         } else {
 500                 set failed_msg [mc "Failed to stage selected line."]
 501                 set to_context {-}
 502                 if {[string index $mi 1] ne {M}} {
 503                         unlock_index
 504                         return
 505                 }
 506         }
 507
 508         set the_l [$ui_diff index @$x,$y]
 509
 510         # operate only on change lines
 511         set c1 [$ui_diff get "$the_l linestart"]
 512         if {$c1 ne {+} && $c1 ne {-}} {
 513                 unlock_index
 514                 return
 515         }
 516         set sign $c1
 517
 518         set i_l [$ui_diff search -backwards -regexp ^@@ $the_l 0.0]
 519         if {$i_l eq {}} {
 520                 unlock_index
 521                 return
 522         }
 523         # $i_l is now at the beginning of a line
 524
 525         # pick start line number from hunk header
 526         set hh [$ui_diff get $i_l "$i_l + 1 lines"]
 527         set hh [lindex [split $hh ,] 0]
 528         set hln [lindex [split $hh -] 1]
 529
 530         # There is a special situation to take care of. Consider this hunk:
 531         #
 532         #    @@ -10,4 +10,4 @@
 533         #     context before
 534         #    -old 1
 535         #    -old 2
 536         #    +new 1
 537         #    +new 2
 538         #     context after
 539         #
 540         # We used to keep the context lines in the order they appear in the
 541         # hunk. But then it is not possible to correctly stage only
 542         # "-old 1" and "+new 1" - it would result in this staged text:
 543         #
 544         #    context before
 545         #    old 2
 546         #    new 1
 547         #    context after
 548         #
 549         # (By symmetry it is not possible to *un*stage "old 2" and "new 2".)
 550         #
 551         # We resolve the problem by introducing an asymmetry, namely, when
 552         # a "+" line is *staged*, it is moved in front of the context lines
 553         # that are generated from the "-" lines that are immediately before
 554         # the "+" block. That is, we construct this patch:
 555         #
 556         #    @@ -10,4 +10,5 @@
 557         #     context before
 558         #    +new 1
 559         #     old 1
 560         #     old 2
 561         #     context after
 562         #
 563         # But we do *not* treat "-" lines that are *un*staged in a special
 564         # way.
 565         #
 566         # With this asymmetry it is possible to stage the change
 567         # "old 1" -> "new 1" directly, and to stage the change
 568         # "old 2" -> "new 2" by first staging the entire hunk and
 569         # then unstaging the change "old 1" -> "new 1".
 570
 571         # This is non-empty if and only if we are _staging_ changes;
 572         # then it accumulates the consecutive "-" lines (after converting
 573         # them to context lines) in order to be moved after the "+" change
 574         # line.
 575         set pre_context {}
 576
 577         set n 0
 578         set i_l [$ui_diff index "$i_l + 1 lines"]
 579         set patch {}
 580         while {[$ui_diff compare $i_l < "end - 1 chars"] &&
 581                [$ui_diff get $i_l "$i_l + 2 chars"] ne {@@}} {
 582                 set next_l [$ui_diff index "$i_l + 1 lines"]
 583                 set c1 [$ui_diff get $i_l]
 584                 if {[$ui_diff compare $i_l <= $the_l] &&
 585                     [$ui_diff compare $the_l < $next_l]} {
 586                         # the line to stage/unstage
 587                         set ln [$ui_diff get $i_l $next_l]
 588                         if {$c1 eq {-}} {
 589                                 set n [expr $n+1]
 590                                 set patch "$patch$pre_context$ln"
 591                         } else {
 592                                 set patch "$patch$ln$pre_context"
 593                         }
 594                         set pre_context {}
 595                 } elseif {$c1 ne {-} && $c1 ne {+}} {
 596                         # context line
 597                         set ln [$ui_diff get $i_l $next_l]
 598                         set patch "$patch$pre_context$ln"
 599                         set n [expr $n+1]
 600                         set pre_context {}
 601                 } elseif {$c1 eq $to_context} {
 602                         # turn change line into context line
 603                         set ln [$ui_diff get "$i_l + 1 chars" $next_l]
 604                         if {$c1 eq {-}} {
 605                                 set pre_context "$pre_context $ln"
 606                         } else {
 607                                 set patch "$patch $ln"
 608                         }
 609                         set n [expr $n+1]
 610                 }
 611                 set i_l $next_l
 612         }
 613         set patch "@@ -$hln,$n +$hln,[eval expr $n $sign 1] @@\n$patch"
 614
 615         if {[catch {
 616                 set enc [get_path_encoding $current_diff_path]
 617                 set p [eval git_write $apply_cmd]
 618                 fconfigure $p -translation binary -encoding $enc
 619                 puts -nonewline $p $current_diff_header
 620                 puts -nonewline $p $patch
 621                 close $p} err]} {
 622                 error_popup [append $failed_msg "\n\n$err"]
 623         }
 624
 625         unlock_index
 626 }