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