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