git.oblomov.eu Git - git/blob - lib/diff.tcl

   1 # git-gui diff viewer
   2 # Copyright (C) 2006, 2007 Shawn Pearce
   3
   4 proc apply_tab_size {{firsttab {}}} {
   5         global have_tk85 repo_config ui_diff
   6
   7         set w [font measure font_diff "0"]
   8         if {$have_tk85 && $firsttab != 0} {
   9                 $ui_diff configure -tabs [list [expr {$firsttab * $w}] [expr {($firsttab + $repo_config(gui.tabsize)) * $w}]]
  10         } elseif {$have_tk85 || $repo_config(gui.tabsize) != 8} {
  11                 $ui_diff configure -tabs [expr {$repo_config(gui.tabsize) * $w}]
  12         } else {
  13                 $ui_diff configure -tabs {}
  14         }
  15 }
  16
  17 proc clear_diff {} {
  18         global ui_diff current_diff_path current_diff_header
  19         global ui_index ui_workdir
  20
  21         $ui_diff conf -state normal
  22         $ui_diff delete 0.0 end
  23         $ui_diff conf -state disabled
  24
  25         set current_diff_path {}
  26         set current_diff_header {}
  27
  28         $ui_index tag remove in_diff 0.0 end
  29         $ui_workdir tag remove in_diff 0.0 end
  30 }
  31
  32 proc reshow_diff {{after {}}} {
  33         global file_states file_lists
  34         global current_diff_path current_diff_side
  35         global ui_diff
  36
  37         set p $current_diff_path
  38         if {$p eq {}} {
  39                 # No diff is being shown.
  40         } elseif {$current_diff_side eq {}} {
  41                 clear_diff
  42         } elseif {[catch {set s $file_states($p)}]
  43                 || [lsearch -sorted -exact $file_lists($current_diff_side) $p] == -1} {
  44
  45                 if {[find_next_diff $current_diff_side $p {} {[^O]}]} {
  46                         next_diff $after
  47                 } else {
  48                         clear_diff
  49                 }
  50         } else {
  51                 set save_pos [lindex [$ui_diff yview] 0]
  52                 show_diff $p $current_diff_side {} $save_pos $after
  53         }
  54 }
  55
  56 proc force_diff_encoding {enc} {
  57         global current_diff_path
  58
  59         if {$current_diff_path ne {}} {
  60                 force_path_encoding $current_diff_path $enc
  61                 reshow_diff
  62         }
  63 }
  64
  65 proc handle_empty_diff {} {
  66         global current_diff_path file_states file_lists
  67         global diff_empty_count
  68
  69         set path $current_diff_path
  70         set s $file_states($path)
  71         if {[lindex $s 0] ne {_M} || [has_textconv $path]} return
  72
  73         # Prevent infinite rescan loops
  74         incr diff_empty_count
  75         if {$diff_empty_count > 1} return
  76
  77         info_popup [mc "No differences detected.
  78
  79 %s has no changes.
  80
  81 The modification date of this file was updated by another application, but the content within the file was not changed.
  82
  83 A rescan will be automatically started to find other files which may have the same state." [short_path $path]]
  84
  85         clear_diff
  86         display_file $path __
  87         rescan ui_ready 0
  88 }
  89
  90 proc show_diff {path w {lno {}} {scroll_pos {}} {callback {}}} {
  91         global file_states file_lists
  92         global is_3way_diff is_conflict_diff diff_active repo_config
  93         global ui_diff ui_index ui_workdir
  94         global current_diff_path current_diff_side current_diff_header
  95         global current_diff_queue
  96
  97         if {$diff_active || ![lock_index read]} return
  98
  99         clear_diff
 100         if {$lno == {}} {
 101                 set lno [lsearch -sorted -exact $file_lists($w) $path]
 102                 if {$lno >= 0} {
 103                         incr lno
 104                 }
 105         }
 106         if {$lno >= 1} {
 107                 $w tag add in_diff $lno.0 [expr {$lno + 1}].0
 108                 $w see $lno.0
 109         }
 110
 111         set s $file_states($path)
 112         set m [lindex $s 0]
 113         set is_conflict_diff 0
 114         set current_diff_path $path
 115         set current_diff_side $w
 116         set current_diff_queue {}
 117         ui_status [mc "Loading diff of %s..." [escape_path $path]]
 118
 119         set cont_info [list $scroll_pos $callback]
 120
 121         apply_tab_size 0
 122
 123         if {[string first {U} $m] >= 0} {
 124                 merge_load_stages $path [list show_unmerged_diff $cont_info]
 125         } elseif {$m eq {_O}} {
 126                 show_other_diff $path $w $m $cont_info
 127         } else {
 128                 start_show_diff $cont_info
 129         }
 130
 131         global current_diff_path selected_paths
 132         set selected_paths($current_diff_path) 1
 133 }
 134
 135 proc show_unmerged_diff {cont_info} {
 136         global current_diff_path current_diff_side
 137         global merge_stages ui_diff is_conflict_diff
 138         global current_diff_queue
 139
 140         if {$merge_stages(2) eq {}} {
 141                 set is_conflict_diff 1
 142                 lappend current_diff_queue \
 143                         [list [mc "LOCAL: deleted\nREMOTE:\n"] d= \
 144                             [list ":1:$current_diff_path" ":3:$current_diff_path"]]
 145         } elseif {$merge_stages(3) eq {}} {
 146                 set is_conflict_diff 1
 147                 lappend current_diff_queue \
 148                         [list [mc "REMOTE: deleted\nLOCAL:\n"] d= \
 149                             [list ":1:$current_diff_path" ":2:$current_diff_path"]]
 150         } elseif {[lindex $merge_stages(1) 0] eq {120000}
 151                 || [lindex $merge_stages(2) 0] eq {120000}
 152                 || [lindex $merge_stages(3) 0] eq {120000}} {
 153                 set is_conflict_diff 1
 154                 lappend current_diff_queue \
 155                         [list [mc "LOCAL:\n"] d= \
 156                             [list ":1:$current_diff_path" ":2:$current_diff_path"]]
 157                 lappend current_diff_queue \
 158                         [list [mc "REMOTE:\n"] d= \
 159                             [list ":1:$current_diff_path" ":3:$current_diff_path"]]
 160         } else {
 161                 start_show_diff $cont_info
 162                 return
 163         }
 164
 165         advance_diff_queue $cont_info
 166 }
 167
 168 proc advance_diff_queue {cont_info} {
 169         global current_diff_queue ui_diff
 170
 171         set item [lindex $current_diff_queue 0]
 172         set current_diff_queue [lrange $current_diff_queue 1 end]
 173
 174         $ui_diff conf -state normal
 175         $ui_diff insert end [lindex $item 0] [lindex $item 1]
 176         $ui_diff conf -state disabled
 177
 178         start_show_diff $cont_info [lindex $item 2]
 179 }
 180
 181 proc show_other_diff {path w m cont_info} {
 182         global file_states file_lists
 183         global is_3way_diff diff_active repo_config
 184         global ui_diff ui_index ui_workdir
 185         global current_diff_path current_diff_side current_diff_header
 186
 187         # - Git won't give us the diff, there's nothing to compare to!
 188         #
 189         if {$m eq {_O}} {
 190                 set max_sz 100000
 191                 set type unknown
 192                 if {[catch {
 193                                 set type [file type $path]
 194                                 switch -- $type {
 195                                 directory {
 196                                         set type submodule
 197                                         set content {}
 198                                         set sz 0
 199                                 }
 200                                 link {
 201                                         set content [file readlink $path]
 202                                         set sz [string length $content]
 203                                 }
 204                                 file {
 205                                         set fd [open $path r]
 206                                         fconfigure $fd \
 207                                                 -eofchar {} \
 208                                                 -encoding [get_path_encoding $path]
 209                                         set content [read $fd $max_sz]
 210                                         close $fd
 211                                         set sz [file size $path]
 212                                 }
 213                                 default {
 214                                         error "'$type' not supported"
 215                                 }
 216                                 }
 217                         } err ]} {
 218                         set diff_active 0
 219                         unlock_index
 220                         ui_status [mc "Unable to display %s" [escape_path $path]]
 221                         error_popup [strcat [mc "Error loading file:"] "\n\n$err"]
 222                         return
 223                 }
 224                 $ui_diff conf -state normal
 225                 if {$type eq {submodule}} {
 226                         $ui_diff insert end [append \
 227                                 "* " \
 228                                 [mc "Git Repository (subproject)"] \
 229                                 "\n"] d_info
 230                 } elseif {![catch {set type [exec file $path]}]} {
 231                         set n [string length $path]
 232                         if {[string equal -length $n $path $type]} {
 233                                 set type [string range $type $n end]
 234                                 regsub {^:?\s*} $type {} type
 235                         }
 236                         $ui_diff insert end "* $type\n" d_info
 237                 }
 238                 if {[string first "\0" $content] != -1} {
 239                         $ui_diff insert end \
 240                                 [mc "* Binary file (not showing content)."] \
 241                                 d_info
 242                 } else {
 243                         if {$sz > $max_sz} {
 244                                 $ui_diff insert end [mc \
 245 "* Untracked file is %d bytes.
 246 * Showing only first %d bytes.
 247 " $sz $max_sz] d_info
 248                         }
 249                         $ui_diff insert end $content
 250                         if {$sz > $max_sz} {
 251                                 $ui_diff insert end [mc "
 252 * Untracked file clipped here by %s.
 253 * To see the entire file, use an external editor.
 254 " [appname]] d_info
 255                         }
 256                 }
 257                 $ui_diff conf -state disabled
 258                 set diff_active 0
 259                 unlock_index
 260                 set scroll_pos [lindex $cont_info 0]
 261                 if {$scroll_pos ne {}} {
 262                         update
 263                         $ui_diff yview moveto $scroll_pos
 264                 }
 265                 ui_ready
 266                 set callback [lindex $cont_info 1]
 267                 if {$callback ne {}} {
 268                         eval $callback
 269                 }
 270                 return
 271         }
 272 }
 273
 274 proc get_conflict_marker_size {path} {
 275         set size 7
 276         catch {
 277                 set fd_rc [eval [list git_read check-attr "conflict-marker-size" -- $path]]
 278                 set ret [gets $fd_rc line]
 279                 close $fd_rc
 280                 if {$ret > 0} {
 281                         regexp {.*: conflict-marker-size: (\d+)$} $line line size
 282                 }
 283         }
 284         return $size
 285 }
 286
 287 proc start_show_diff {cont_info {add_opts {}}} {
 288         global file_states file_lists
 289         global is_3way_diff is_submodule_diff diff_active repo_config
 290         global ui_diff ui_index ui_workdir
 291         global current_diff_path current_diff_side current_diff_header
 292
 293         set path $current_diff_path
 294         set w $current_diff_side
 295
 296         set s $file_states($path)
 297         set m [lindex $s 0]
 298         set is_3way_diff 0
 299         set is_submodule_diff 0
 300         set diff_active 1
 301         set current_diff_header {}
 302         set conflict_size [get_conflict_marker_size $path]
 303
 304         set cmd [list]
 305         if {$w eq $ui_index} {
 306                 lappend cmd diff-index
 307                 lappend cmd --cached
 308                 if {[git-version >= "1.7.2"]} {
 309                         lappend cmd --ignore-submodules=dirty
 310                 }
 311         } elseif {$w eq $ui_workdir} {
 312                 if {[string first {U} $m] >= 0} {
 313                         lappend cmd diff
 314                 } else {
 315                         lappend cmd diff-files
 316                 }
 317         }
 318         if {![is_config_false gui.textconv] && [git-version >= 1.6.1]} {
 319                 lappend cmd --textconv
 320         }
 321
 322         if {[string match {160000 *} [lindex $s 2]]
 323          || [string match {160000 *} [lindex $s 3]]} {
 324                 set is_submodule_diff 1
 325
 326                 if {[git-version >= "1.6.6"]} {
 327                         lappend cmd --submodule
 328                 }
 329         }
 330
 331         lappend cmd -p
 332         lappend cmd --color
 333         set cmd [concat $cmd $repo_config(gui.diffopts)]
 334         if {$repo_config(gui.diffcontext) >= 1} {
 335                 lappend cmd "-U$repo_config(gui.diffcontext)"
 336         }
 337         if {$w eq $ui_index} {
 338                 lappend cmd [PARENT]
 339         }
 340         if {$add_opts ne {}} {
 341                 eval lappend cmd $add_opts
 342         } else {
 343                 lappend cmd --
 344                 lappend cmd $path
 345         }
 346
 347         if {$is_submodule_diff && [git-version < "1.6.6"]} {
 348                 if {$w eq $ui_index} {
 349                         set cmd [list submodule summary --cached -- $path]
 350                 } else {
 351                         set cmd [list submodule summary --files -- $path]
 352                 }
 353         }
 354
 355         if {[catch {set fd [eval git_read --nice $cmd]} err]} {
 356                 set diff_active 0
 357                 unlock_index
 358                 ui_status [mc "Unable to display %s" [escape_path $path]]
 359                 error_popup [strcat [mc "Error loading diff:"] "\n\n$err"]
 360                 return
 361         }
 362
 363         set ::current_diff_inheader 1
 364         fconfigure $fd \
 365                 -blocking 0 \
 366                 -encoding [get_path_encoding $path] \
 367                 -translation lf
 368         fileevent $fd readable [list read_diff $fd $conflict_size $cont_info]
 369 }
 370
 371 proc parse_color_line {line} {
 372         set start 0
 373         set result ""
 374         set markup [list]
 375         set regexp {\033\[((?:\d+;)*\d+)?m}
 376         set need_reset 0
 377         while {[regexp -indices -start $start $regexp $line match code]} {
 378                 foreach {begin end} $match break
 379                 append result [string range $line $start [expr {$begin - 1}]]
 380                 set pos [string length $result]
 381                 set col [eval [linsert $code 0 string range $line]]
 382                 set start [incr end]
 383                 if {$col eq "0" || $col eq ""} {
 384                         if {!$need_reset} continue
 385                         set need_reset 0
 386                 } else {
 387                         set need_reset 1
 388                 }
 389                 lappend markup $pos $col
 390         }
 391         append result [string range $line $start end]
 392         if {[llength $markup] < 4} {set markup {}}
 393         return [list $result $markup]
 394 }
 395
 396 proc read_diff {fd conflict_size cont_info} {
 397         global ui_diff diff_active is_submodule_diff
 398         global is_3way_diff is_conflict_diff current_diff_header
 399         global current_diff_queue
 400         global diff_empty_count
 401
 402         $ui_diff conf -state normal
 403         while {[gets $fd line] >= 0} {
 404                 foreach {line markup} [parse_color_line $line] break
 405                 set line [string map {\033 ^} $line]
 406
 407                 set tags {}
 408
 409                 # -- Check for start of diff header.
 410                 if {   [string match {diff --git *}      $line]
 411                     || [string match {diff --cc *}       $line]
 412                     || [string match {diff --combined *} $line]} {
 413                         set ::current_diff_inheader 1
 414                 }
 415
 416                 # -- Check for end of diff header (any hunk line will do this).
 417                 #
 418                 if {[regexp {^@@+ } $line]} {set ::current_diff_inheader 0}
 419
 420                 # -- Automatically detect if this is a 3 way diff.
 421                 #
 422                 if {[string match {@@@ *} $line]} {
 423                         set is_3way_diff 1
 424                         apply_tab_size 1
 425                 }
 426
 427                 if {$::current_diff_inheader} {
 428
 429                         # -- These two lines stop a diff header and shouldn't be in there
 430                         if {   [string match {Binary files * and * differ} $line]
 431                             || [regexp {^\* Unmerged path }                $line]} {
 432                                 set ::current_diff_inheader 0
 433                         } else {
 434                                 append current_diff_header $line "\n"
 435                         }
 436
 437                         # -- Cleanup uninteresting diff header lines.
 438                         #
 439                         if {   [string match {diff --git *}      $line]
 440                             || [string match {diff --cc *}       $line]
 441                             || [string match {diff --combined *} $line]
 442                             || [string match {--- *}             $line]
 443                             || [string match {+++ *}             $line]
 444                             || [string match {index *}           $line]} {
 445                                 continue
 446                         }
 447
 448                         # -- Name it symlink, not 120000
 449                         #    Note, that the original line is in $current_diff_header
 450                         regsub {^(deleted|new) file mode 120000} $line {\1 symlink} line
 451
 452                 } elseif {   $line eq {\ No newline at end of file}} {
 453                         # -- Handle some special lines
 454                 } elseif {$is_3way_diff} {
 455                         set op [string range $line 0 1]
 456                         switch -- $op {
 457                         {  } {set tags {}}
 458                         {@@} {set tags d_@}
 459                         { +} {set tags d_s+}
 460                         { -} {set tags d_s-}
 461                         {+ } {set tags d_+s}
 462                         {- } {set tags d_-s}
 463                         {--} {set tags d_--}
 464                         {++} {
 465                                 set regexp [string map [list %conflict_size $conflict_size]\
 466                                                                 {^\+\+([<>=]){%conflict_size}(?: |$)}]
 467                                 if {[regexp $regexp $line _g op]} {
 468                                         set is_conflict_diff 1
 469                                         set line [string replace $line 0 1 {  }]
 470                                         set tags d$op
 471                                 } else {
 472                                         set tags d_++
 473                                 }
 474                         }
 475                         default {
 476                                 puts "error: Unhandled 3 way diff marker: {$op}"
 477                                 set tags {}
 478                         }
 479                         }
 480                 } elseif {$is_submodule_diff} {
 481                         if {$line == ""} continue
 482                         if {[regexp {^Submodule } $line]} {
 483                                 set tags d_info
 484                         } elseif {[regexp {^\* } $line]} {
 485                                 set line [string replace $line 0 1 {Submodule }]
 486                                 set tags d_info
 487                         } else {
 488                                 set op [string range $line 0 2]
 489                                 switch -- $op {
 490                                 {  <} {set tags d_-}
 491                                 {  >} {set tags d_+}
 492                                 {  W} {set tags {}}
 493                                 default {
 494                                         puts "error: Unhandled submodule diff marker: {$op}"
 495                                         set tags {}
 496                                 }
 497                                 }
 498                         }
 499                 } else {
 500                         set op [string index $line 0]
 501                         switch -- $op {
 502                         { } {set tags {}}
 503                         {@} {set tags d_@}
 504                         {-} {set tags d_-}
 505                         {+} {
 506                                 set regexp [string map [list %conflict_size $conflict_size]\
 507                                                                 {^\+([<>=]){%conflict_size}(?: |$)}]
 508                                 if {[regexp $regexp $line _g op]} {
 509                                         set is_conflict_diff 1
 510                                         set tags d$op
 511                                 } else {
 512                                         set tags d_+
 513                                 }
 514                         }
 515                         default {
 516                                 puts "error: Unhandled 2 way diff marker: {$op}"
 517                                 set tags {}
 518                         }
 519                         }
 520                 }
 521                 set mark [$ui_diff index "end - 1 line linestart"]
 522                 $ui_diff insert end $line $tags
 523                 if {[string index $line end] eq "\r"} {
 524                         $ui_diff tag add d_cr {end - 2c}
 525                 }
 526                 $ui_diff insert end "\n" $tags
 527
 528                 foreach {posbegin colbegin posend colend} $markup {
 529                         set prefix clr
 530                         foreach style [lsort -integer [split $colbegin ";"]] {
 531                                 if {$style eq "7"} {append prefix i; continue}
 532                                 if {$style != 4 && ($style < 30 || $style > 47)} {continue}
 533                                 set a "$mark linestart + $posbegin chars"
 534                                 set b "$mark linestart + $posend chars"
 535                                 catch {$ui_diff tag add $prefix$style $a $b}
 536                         }
 537                 }
 538         }
 539         $ui_diff conf -state disabled
 540
 541         if {[eof $fd]} {
 542                 close $fd
 543
 544                 if {$current_diff_queue ne {}} {
 545                         advance_diff_queue $cont_info
 546                         return
 547                 }
 548
 549                 set diff_active 0
 550                 unlock_index
 551                 set scroll_pos [lindex $cont_info 0]
 552                 if {$scroll_pos ne {}} {
 553                         update
 554                         $ui_diff yview moveto $scroll_pos
 555                 }
 556                 ui_ready
 557
 558                 if {[$ui_diff index end] eq {2.0}} {
 559                         handle_empty_diff
 560                 } else {
 561                         set diff_empty_count 0
 562                 }
 563
 564                 set callback [lindex $cont_info 1]
 565                 if {$callback ne {}} {
 566                         eval $callback
 567                 }
 568         }
 569 }
 570
 571 proc apply_hunk {x y} {
 572         global current_diff_path current_diff_header current_diff_side
 573         global ui_diff ui_index file_states
 574
 575         if {$current_diff_path eq {} || $current_diff_header eq {}} return
 576         if {![lock_index apply_hunk]} return
 577
 578         set apply_cmd {apply --cached --whitespace=nowarn}
 579         set mi [lindex $file_states($current_diff_path) 0]
 580         if {$current_diff_side eq $ui_index} {
 581                 set failed_msg [mc "Failed to unstage selected hunk."]
 582                 lappend apply_cmd --reverse
 583                 if {[string index $mi 0] ne {M}} {
 584                         unlock_index
 585                         return
 586                 }
 587         } else {
 588                 set failed_msg [mc "Failed to stage selected hunk."]
 589                 if {[string index $mi 1] ne {M}} {
 590                         unlock_index
 591                         return
 592                 }
 593         }
 594
 595         set s_lno [lindex [split [$ui_diff index @$x,$y] .] 0]
 596         set s_lno [$ui_diff search -backwards -regexp ^@@ $s_lno.0 0.0]
 597         if {$s_lno eq {}} {
 598                 unlock_index
 599                 return
 600         }
 601
 602         set e_lno [$ui_diff search -forwards -regexp ^@@ "$s_lno + 1 lines" end]
 603         if {$e_lno eq {}} {
 604                 set e_lno end
 605         }
 606
 607         if {[catch {
 608                 set enc [get_path_encoding $current_diff_path]
 609                 set p [eval git_write $apply_cmd]
 610                 fconfigure $p -translation binary -encoding $enc
 611                 puts -nonewline $p $current_diff_header
 612                 puts -nonewline $p [$ui_diff get $s_lno $e_lno]
 613                 close $p} err]} {
 614                 error_popup [append $failed_msg "\n\n$err"]
 615                 unlock_index
 616                 return
 617         }
 618
 619         $ui_diff conf -state normal
 620         $ui_diff delete $s_lno $e_lno
 621         $ui_diff conf -state disabled
 622
 623         if {[$ui_diff get 1.0 end] eq "\n"} {
 624                 set o _
 625         } else {
 626                 set o ?
 627         }
 628
 629         if {$current_diff_side eq $ui_index} {
 630                 set mi ${o}M
 631         } elseif {[string index $mi 0] eq {_}} {
 632                 set mi M$o
 633         } else {
 634                 set mi ?$o
 635         }
 636         unlock_index
 637         display_file $current_diff_path $mi
 638         # This should trigger shift to the next changed file
 639         if {$o eq {_}} {
 640                 reshow_diff
 641         }
 642 }
 643
 644 proc apply_range_or_line {x y} {
 645         global current_diff_path current_diff_header current_diff_side
 646         global ui_diff ui_index file_states
 647
 648         set selected [$ui_diff tag nextrange sel 0.0]
 649
 650         if {$selected == {}} {
 651                 set first [$ui_diff index "@$x,$y"]
 652                 set last $first
 653         } else {
 654                 set first [lindex $selected 0]
 655                 set last [lindex $selected 1]
 656         }
 657
 658         set first_l [$ui_diff index "$first linestart"]
 659         set last_l [$ui_diff index "$last lineend"]
 660
 661         if {$current_diff_path eq {} || $current_diff_header eq {}} return
 662         if {![lock_index apply_hunk]} return
 663
 664         set apply_cmd {apply --cached --whitespace=nowarn}
 665         set mi [lindex $file_states($current_diff_path) 0]
 666         if {$current_diff_side eq $ui_index} {
 667                 set failed_msg [mc "Failed to unstage selected line."]
 668                 set to_context {+}
 669                 lappend apply_cmd --reverse
 670                 if {[string index $mi 0] ne {M}} {
 671                         unlock_index
 672                         return
 673                 }
 674         } else {
 675                 set failed_msg [mc "Failed to stage selected line."]
 676                 set to_context {-}
 677                 if {[string index $mi 1] ne {M}} {
 678                         unlock_index
 679                         return
 680                 }
 681         }
 682
 683         set wholepatch {}
 684
 685         while {$first_l < $last_l} {
 686                 set i_l [$ui_diff search -backwards -regexp ^@@ $first_l 0.0]
 687                 if {$i_l eq {}} {
 688                         # If there's not a @@ above, then the selected range
 689                         # must have come before the first_l @@
 690                         set i_l [$ui_diff search -regexp ^@@ $first_l $last_l]
 691                 }
 692                 if {$i_l eq {}} {
 693                         unlock_index
 694                         return
 695                 }
 696                 # $i_l is now at the beginning of a line
 697
 698                 # pick start line number from hunk header
 699                 set hh [$ui_diff get $i_l "$i_l + 1 lines"]
 700                 set hh [lindex [split $hh ,] 0]
 701                 set hln [lindex [split $hh -] 1]
 702
 703                 # There is a special situation to take care of. Consider this
 704                 # hunk:
 705                 #
 706                 #    @@ -10,4 +10,4 @@
 707                 #     context before
 708                 #    -old 1
 709                 #    -old 2
 710                 #    +new 1
 711                 #    +new 2
 712                 #     context after
 713                 #
 714                 # We used to keep the context lines in the order they appear in
 715                 # the hunk. But then it is not possible to correctly stage only
 716                 # "-old 1" and "+new 1" - it would result in this staged text:
 717                 #
 718                 #    context before
 719                 #    old 2
 720                 #    new 1
 721                 #    context after
 722                 #
 723                 # (By symmetry it is not possible to *un*stage "old 2" and "new
 724                 # 2".)
 725                 #
 726                 # We resolve the problem by introducing an asymmetry, namely,
 727                 # when a "+" line is *staged*, it is moved in front of the
 728                 # context lines that are generated from the "-" lines that are
 729                 # immediately before the "+" block. That is, we construct this
 730                 # patch:
 731                 #
 732                 #    @@ -10,4 +10,5 @@
 733                 #     context before
 734                 #    +new 1
 735                 #     old 1
 736                 #     old 2
 737                 #     context after
 738                 #
 739                 # But we do *not* treat "-" lines that are *un*staged in a
 740                 # special way.
 741                 #
 742                 # With this asymmetry it is possible to stage the change "old
 743                 # 1" -> "new 1" directly, and to stage the change "old 2" ->
 744                 # "new 2" by first staging the entire hunk and then unstaging
 745                 # the change "old 1" -> "new 1".
 746                 #
 747                 # Applying multiple lines adds complexity to the special
 748                 # situation.  The pre_context must be moved after the entire
 749                 # first block of consecutive staged "+" lines, so that
 750                 # staging both additions gives the following patch:
 751                 #
 752                 #    @@ -10,4 +10,6 @@
 753                 #     context before
 754                 #    +new 1
 755                 #    +new 2
 756                 #     old 1
 757                 #     old 2
 758                 #     context after
 759
 760                 # This is non-empty if and only if we are _staging_ changes;
 761                 # then it accumulates the consecutive "-" lines (after
 762                 # converting them to context lines) in order to be moved after
 763                 # "+" change lines.
 764                 set pre_context {}
 765
 766                 set n 0
 767                 set m 0
 768                 set i_l [$ui_diff index "$i_l + 1 lines"]
 769                 set patch {}
 770                 while {[$ui_diff compare $i_l < "end - 1 chars"] &&
 771                        [$ui_diff get $i_l "$i_l + 2 chars"] ne {@@}} {
 772                         set next_l [$ui_diff index "$i_l + 1 lines"]
 773                         set c1 [$ui_diff get $i_l]
 774                         if {[$ui_diff compare $first_l <= $i_l] &&
 775                             [$ui_diff compare $i_l < $last_l] &&
 776                             ($c1 eq {-} || $c1 eq {+})} {
 777                                 # a line to stage/unstage
 778                                 set ln [$ui_diff get $i_l $next_l]
 779                                 if {$c1 eq {-}} {
 780                                         set n [expr $n+1]
 781                                         set patch "$patch$pre_context$ln"
 782                                         set pre_context {}
 783                                 } else {
 784                                         set m [expr $m+1]
 785                                         set patch "$patch$ln"
 786                                 }
 787                         } elseif {$c1 ne {-} && $c1 ne {+}} {
 788                                 # context line
 789                                 set ln [$ui_diff get $i_l $next_l]
 790                                 set patch "$patch$pre_context$ln"
 791                                 # Skip the "\ No newline at end of
 792                                 # file". Depending on the locale setting
 793                                 # we don't know what this line looks
 794                                 # like exactly. The only thing we do
 795                                 # know is that it starts with "\ "
 796                                 if {![string match {\\ *} $ln]} {
 797                                         set n [expr $n+1]
 798                                         set m [expr $m+1]
 799                                 }
 800                                 set pre_context {}
 801                         } elseif {$c1 eq $to_context} {
 802                                 # turn change line into context line
 803                                 set ln [$ui_diff get "$i_l + 1 chars" $next_l]
 804                                 if {$c1 eq {-}} {
 805                                         set pre_context "$pre_context $ln"
 806                                 } else {
 807                                         set patch "$patch $ln"
 808                                 }
 809                                 set n [expr $n+1]
 810                                 set m [expr $m+1]
 811                         } else {
 812                                 # a change in the opposite direction of
 813                                 # to_context which is outside the range of
 814                                 # lines to apply.
 815                                 set patch "$patch$pre_context"
 816                                 set pre_context {}
 817                         }
 818                         set i_l $next_l
 819                 }
 820                 set patch "$patch$pre_context"
 821                 set wholepatch "$wholepatch@@ -$hln,$n +$hln,$m @@\n$patch"
 822                 set first_l [$ui_diff index "$next_l + 1 lines"]
 823         }
 824
 825         if {[catch {
 826                 set enc [get_path_encoding $current_diff_path]
 827                 set p [eval git_write $apply_cmd]
 828                 fconfigure $p -translation binary -encoding $enc
 829                 puts -nonewline $p $current_diff_header
 830                 puts -nonewline $p $wholepatch
 831                 close $p} err]} {
 832                 error_popup [append $failed_msg "\n\n$err"]
 833         }
 834
 835         unlock_index
 836 }