perl/Git/SVN/Editor.pm

   1 package Git::SVN::Editor;
   2 use vars qw/@ISA $_rmdir $_cp_similarity $_find_copies_harder $_rename_limit/;
   3 use strict;
   4 use warnings;
   5 use SVN::Core;
   6 use SVN::Delta;
   7 use Carp qw/croak/;
   8 use Git qw/command command_oneline command_noisy command_output_pipe
   9            command_input_pipe command_close_pipe
  10            command_bidi_pipe command_close_bidi_pipe/;
  11 BEGIN {
  12         @ISA = qw(SVN::Delta::Editor);
  13 }
  14
  15 sub new {
  16         my ($class, $opts) = @_;
  17         foreach (qw/svn_path r ra tree_a tree_b log editor_cb/) {
  18                 die "$_ required!\n" unless (defined $opts->{$_});
  19         }
  20
  21         my $pool = SVN::Pool->new;
  22         my $mods = generate_diff($opts->{tree_a}, $opts->{tree_b});
  23         my $types = check_diff_paths($opts->{ra}, $opts->{svn_path},
  24                                      $opts->{r}, $mods);
  25
  26         # $opts->{ra} functions should not be used after this:
  27         my @ce  = $opts->{ra}->get_commit_editor($opts->{log},
  28                                                 $opts->{editor_cb}, $pool);
  29         my $self = SVN::Delta::Editor->new(@ce, $pool);
  30         bless $self, $class;
  31         foreach (qw/svn_path r tree_a tree_b/) {
  32                 $self->{$_} = $opts->{$_};
  33         }
  34         $self->{url} = $opts->{ra}->{url};
  35         $self->{mods} = $mods;
  36         $self->{types} = $types;
  37         $self->{pool} = $pool;
  38         $self->{bat} = { '' => $self->open_root($self->{r}, $self->{pool}) };
  39         $self->{rm} = { };
  40         $self->{path_prefix} = length $self->{svn_path} ?
  41                                "$self->{svn_path}/" : '';
  42         $self->{config} = $opts->{config};
  43         $self->{mergeinfo} = $opts->{mergeinfo};
  44         return $self;
  45 }
  46
  47 sub generate_diff {
  48         my ($tree_a, $tree_b) = @_;
  49         my @diff_tree = qw(diff-tree -z -r);
  50         if ($_cp_similarity) {
  51                 push @diff_tree, "-C$_cp_similarity";
  52         } else {
  53                 push @diff_tree, '-C';
  54         }
  55         push @diff_tree, '--find-copies-harder' if $_find_copies_harder;
  56         push @diff_tree, "-l$_rename_limit" if defined $_rename_limit;
  57         push @diff_tree, $tree_a, $tree_b;
  58         my ($diff_fh, $ctx) = command_output_pipe(@diff_tree);
  59         local $/ = "\0";
  60         my $state = 'meta';
  61         my @mods;
  62         while (<$diff_fh>) {
  63                 chomp $_; # this gets rid of the trailing "\0"
  64                 if ($state eq 'meta' && /^:(\d{6})\s(\d{6})\s
  65                                         ($::sha1)\s($::sha1)\s
  66                                         ([MTCRAD])\d*$/xo) {
  67                         push @mods, {   mode_a => $1, mode_b => $2,
  68                                         sha1_a => $3, sha1_b => $4,
  69                                         chg => $5 };
  70                         if ($5 =~ /^(?:C|R)$/) {
  71                                 $state = 'file_a';
  72                         } else {
  73                                 $state = 'file_b';
  74                         }
  75                 } elsif ($state eq 'file_a') {
  76                         my $x = $mods[$#mods] or croak "Empty array\n";
  77                         if ($x->{chg} !~ /^(?:C|R)$/) {
  78                                 croak "Error parsing $_, $x->{chg}\n";
  79                         }
  80                         $x->{file_a} = $_;
  81                         $state = 'file_b';
  82                 } elsif ($state eq 'file_b') {
  83                         my $x = $mods[$#mods] or croak "Empty array\n";
  84                         if (exists $x->{file_a} && $x->{chg} !~ /^(?:C|R)$/) {
  85                                 croak "Error parsing $_, $x->{chg}\n";
  86                         }
  87                         if (!exists $x->{file_a} && $x->{chg} =~ /^(?:C|R)$/) {
  88                                 croak "Error parsing $_, $x->{chg}\n";
  89                         }
  90                         $x->{file_b} = $_;
  91                         $state = 'meta';
  92                 } else {
  93                         croak "Error parsing $_\n";
  94                 }
  95         }
  96         command_close_pipe($diff_fh, $ctx);
  97         \@mods;
  98 }
  99
 100 sub check_diff_paths {
 101         my ($ra, $pfx, $rev, $mods) = @_;
 102         my %types;
 103         $pfx .= '/' if length $pfx;
 104
 105         sub type_diff_paths {
 106                 my ($ra, $types, $path, $rev) = @_;
 107                 my @p = split m#/+#, $path;
 108                 my $c = shift @p;
 109                 unless (defined $types->{$c}) {
 110                         $types->{$c} = $ra->check_path($c, $rev);
 111                 }
 112                 while (@p) {
 113                         $c .= '/' . shift @p;
 114                         next if defined $types->{$c};
 115                         $types->{$c} = $ra->check_path($c, $rev);
 116                 }
 117         }
 118
 119         foreach my $m (@$mods) {
 120                 foreach my $f (qw/file_a file_b/) {
 121                         next unless defined $m->{$f};
 122                         my ($dir) = ($m->{$f} =~ m#^(.*?)/?(?:[^/]+)$#);
 123                         if (length $pfx.$dir && ! defined $types{$dir}) {
 124                                 type_diff_paths($ra, \%types, $pfx.$dir, $rev);
 125                         }
 126                 }
 127         }
 128         \%types;
 129 }
 130
 131 sub split_path {
 132         return ($_[0] =~ m#^(.*?)/?([^/]+)$#);
 133 }
 134
 135 sub repo_path {
 136         my ($self, $path) = @_;
 137         if (my $enc = $self->{pathnameencoding}) {
 138                 require Encode;
 139                 Encode::from_to($path, $enc, 'UTF-8');
 140         }
 141         $self->{path_prefix}.(defined $path ? $path : '');
 142 }
 143
 144 sub url_path {
 145         my ($self, $path) = @_;
 146         if ($self->{url} =~ m#^https?://#) {
 147                 # characters are taken from subversion/libsvn_subr/path.c
 148                 $path =~ s#([^~a-zA-Z0-9_./!$&'()*+,-])#sprintf("%%%02X",ord($1))#eg;
 149         }
 150         $self->{url} . '/' . $self->repo_path($path);
 151 }
 152
 153 sub rmdirs {
 154         my ($self) = @_;
 155         my $rm = $self->{rm};
 156         delete $rm->{''}; # we never delete the url we're tracking
 157         return unless %$rm;
 158
 159         foreach (keys %$rm) {
 160                 my @d = split m#/#, $_;
 161                 my $c = shift @d;
 162                 $rm->{$c} = 1;
 163                 while (@d) {
 164                         $c .= '/' . shift @d;
 165                         $rm->{$c} = 1;
 166                 }
 167         }
 168         delete $rm->{$self->{svn_path}};
 169         delete $rm->{''}; # we never delete the url we're tracking
 170         return unless %$rm;
 171
 172         my ($fh, $ctx) = command_output_pipe(qw/ls-tree --name-only -r -z/,
 173                                              $self->{tree_b});
 174         local $/ = "\0";
 175         while (<$fh>) {
 176                 chomp;
 177                 my @dn = split m#/#, $_;
 178                 while (pop @dn) {
 179                         delete $rm->{join '/', @dn};
 180                 }
 181                 unless (%$rm) {
 182                         close $fh;
 183                         return;
 184                 }
 185         }
 186         command_close_pipe($fh, $ctx);
 187
 188         my ($r, $p, $bat) = ($self->{r}, $self->{pool}, $self->{bat});
 189         foreach my $d (sort { $b =~ tr#/#/# <=> $a =~ tr#/#/# } keys %$rm) {
 190                 $self->close_directory($bat->{$d}, $p);
 191                 my ($dn) = ($d =~ m#^(.*?)/?(?:[^/]+)$#);
 192                 print "\tD+\t$d/\n" unless $::_q;
 193                 $self->SUPER::delete_entry($d, $r, $bat->{$dn}, $p);
 194                 delete $bat->{$d};
 195         }
 196 }
 197
 198 sub open_or_add_dir {
 199         my ($self, $full_path, $baton, $deletions) = @_;
 200         my $t = $self->{types}->{$full_path};
 201         if (!defined $t) {
 202                 die "$full_path not known in r$self->{r} or we have a bug!\n";
 203         }
 204         {
 205                 no warnings 'once';
 206                 # SVN::Node::none and SVN::Node::file are used only once,
 207                 # so we're shutting up Perl's warnings about them.
 208                 if ($t == $SVN::Node::none || defined($deletions->{$full_path})) {
 209                         return $self->add_directory($full_path, $baton,
 210                             undef, -1, $self->{pool});
 211                 } elsif ($t == $SVN::Node::dir) {
 212                         return $self->open_directory($full_path, $baton,
 213                             $self->{r}, $self->{pool});
 214                 } # no warnings 'once'
 215                 print STDERR "$full_path already exists in repository at ",
 216                     "r$self->{r} and it is not a directory (",
 217                     ($t == $SVN::Node::file ? 'file' : 'unknown'),"/$t)\n";
 218         } # no warnings 'once'
 219         exit 1;
 220 }
 221
 222 sub ensure_path {
 223         my ($self, $path, $deletions) = @_;
 224         my $bat = $self->{bat};
 225         my $repo_path = $self->repo_path($path);
 226         return $bat->{''} unless (length $repo_path);
 227
 228         my @p = split m#/+#, $repo_path;
 229         my $c = shift @p;
 230         $bat->{$c} ||= $self->open_or_add_dir($c, $bat->{''}, $deletions);
 231         while (@p) {
 232                 my $c0 = $c;
 233                 $c .= '/' . shift @p;
 234                 $bat->{$c} ||= $self->open_or_add_dir($c, $bat->{$c0}, $deletions);
 235         }
 236         return $bat->{$c};
 237 }
 238
 239 # Subroutine to convert a globbing pattern to a regular expression.
 240 # From perl cookbook.
 241 sub glob2pat {
 242         my $globstr = shift;
 243         my %patmap = ('*' => '.*', '?' => '.', '[' => '[', ']' => ']');
 244         $globstr =~ s{(.)} { $patmap{$1} || "\Q$1" }ge;
 245         return '^' . $globstr . '$';
 246 }
 247
 248 sub check_autoprop {
 249         my ($self, $pattern, $properties, $file, $fbat) = @_;
 250         # Convert the globbing pattern to a regular expression.
 251         my $regex = glob2pat($pattern);
 252         # Check if the pattern matches the file name.
 253         if($file =~ m/($regex)/) {
 254                 # Parse the list of properties to set.
 255                 my @props = split(/;/, $properties);
 256                 foreach my $prop (@props) {
 257                         # Parse 'name=value' syntax and set the property.
 258                         if ($prop =~ /([^=]+)=(.*)/) {
 259                                 my ($n,$v) = ($1,$2);
 260                                 for ($n, $v) {
 261                                         s/^\s+//; s/\s+$//;
 262                                 }
 263                                 $self->change_file_prop($fbat, $n, $v);
 264                         }
 265                 }
 266         }
 267 }
 268
 269 sub apply_autoprops {
 270         my ($self, $file, $fbat) = @_;
 271         my $conf_t = ${$self->{config}}{'config'};
 272         no warnings 'once';
 273         # Check [miscellany]/enable-auto-props in svn configuration.
 274         if (SVN::_Core::svn_config_get_bool(
 275                 $conf_t,
 276                 $SVN::_Core::SVN_CONFIG_SECTION_MISCELLANY,
 277                 $SVN::_Core::SVN_CONFIG_OPTION_ENABLE_AUTO_PROPS,
 278                 0)) {
 279                 # Auto-props are enabled.  Enumerate them to look for matches.
 280                 my $callback = sub {
 281                         $self->check_autoprop($_[0], $_[1], $file, $fbat);
 282                 };
 283                 SVN::_Core::svn_config_enumerate(
 284                         $conf_t,
 285                         $SVN::_Core::SVN_CONFIG_SECTION_AUTO_PROPS,
 286                         $callback);
 287         }
 288 }
 289
 290 sub check_attr {
 291         my ($attr,$path) = @_;
 292         my $val = command_oneline("check-attr", $attr, "--", $path);
 293         if ($val) { $val =~ s/^[^:]*:\s*[^:]*:\s*(.*)\s*$/$1/; }
 294         return $val;
 295 }
 296
 297 sub apply_manualprops {
 298         my ($self, $file, $fbat) = @_;
 299         my $pending_properties = check_attr( "svn-properties", $file );
 300         if ($pending_properties eq "") { return; }
 301         # Parse the list of properties to set.
 302         my @props = split(/;/, $pending_properties);
 303         # TODO: get existing properties to compare to
 304         # - this fails for add so currently not done
 305         # my $existing_props = ::get_svnprops($file);
 306         my $existing_props = {};
 307         # TODO: caching svn properties or storing them in .gitattributes
 308         # would make that faster
 309         foreach my $prop (@props) {
 310                 # Parse 'name=value' syntax and set the property.
 311                 if ($prop =~ /([^=]+)=(.*)/) {
 312                         my ($n,$v) = ($1,$2);
 313                         for ($n, $v) {
 314                                 s/^\s+//; s/\s+$//;
 315                         }
 316                         my $existing = $existing_props->{$n};
 317                         if (!defined($existing) || $existing ne $v) {
 318                             $self->change_file_prop($fbat, $n, $v);
 319                         }
 320                 }
 321         }
 322 }
 323
 324 sub A {
 325         my ($self, $m, $deletions) = @_;
 326         my ($dir, $file) = split_path($m->{file_b});
 327         my $pbat = $self->ensure_path($dir, $deletions);
 328         my $fbat = $self->add_file($self->repo_path($m->{file_b}), $pbat,
 329                                         undef, -1);
 330         print "\tA\t$m->{file_b}\n" unless $::_q;
 331         $self->apply_autoprops($file, $fbat);
 332         $self->apply_manualprops($m->{file_b}, $fbat);
 333         $self->chg_file($fbat, $m);
 334         $self->close_file($fbat,undef,$self->{pool});
 335 }
 336
 337 sub C {
 338         my ($self, $m, $deletions) = @_;
 339         my ($dir, $file) = split_path($m->{file_b});
 340         my $pbat = $self->ensure_path($dir, $deletions);
 341         # workaround for a bug in svn serf backend (v1.8.5 and below):
 342         # store third argument to ->add_file() in a local variable, to make it
 343         # have the same lifetime as $fbat
 344         my $upa = $self->url_path($m->{file_a});
 345         my $fbat = $self->add_file($self->repo_path($m->{file_b}), $pbat,
 346                                 $upa, $self->{r});
 347         print "\tC\t$m->{file_a} => $m->{file_b}\n" unless $::_q;
 348         $self->apply_manualprops($m->{file_b}, $fbat);
 349         $self->chg_file($fbat, $m);
 350         $self->close_file($fbat,undef,$self->{pool});
 351 }
 352
 353 sub delete_entry {
 354         my ($self, $path, $pbat) = @_;
 355         my $rpath = $self->repo_path($path);
 356         my ($dir, $file) = split_path($rpath);
 357         $self->{rm}->{$dir} = 1;
 358         $self->SUPER::delete_entry($rpath, $self->{r}, $pbat, $self->{pool});
 359 }
 360
 361 sub R {
 362         my ($self, $m, $deletions) = @_;
 363         my ($dir, $file) = split_path($m->{file_b});
 364         my $pbat = $self->ensure_path($dir, $deletions);
 365         # workaround for a bug in svn serf backend, see comment in C() above
 366         my $upa = $self->url_path($m->{file_a});
 367         my $fbat = $self->add_file($self->repo_path($m->{file_b}), $pbat,
 368                                 $upa, $self->{r});
 369         print "\tR\t$m->{file_a} => $m->{file_b}\n" unless $::_q;
 370         $self->apply_autoprops($file, $fbat);
 371         $self->apply_manualprops($m->{file_b}, $fbat);
 372         $self->chg_file($fbat, $m);
 373         $self->close_file($fbat,undef,$self->{pool});
 374
 375         ($dir, $file) = split_path($m->{file_a});
 376         $pbat = $self->ensure_path($dir, $deletions);
 377         $self->delete_entry($m->{file_a}, $pbat);
 378 }
 379
 380 sub M {
 381         my ($self, $m, $deletions) = @_;
 382         my ($dir, $file) = split_path($m->{file_b});
 383         my $pbat = $self->ensure_path($dir, $deletions);
 384         my $fbat = $self->open_file($self->repo_path($m->{file_b}),
 385                                 $pbat,$self->{r},$self->{pool});
 386         print "\t$m->{chg}\t$m->{file_b}\n" unless $::_q;
 387         $self->apply_manualprops($m->{file_b}, $fbat);
 388         $self->chg_file($fbat, $m);
 389         $self->close_file($fbat,undef,$self->{pool});
 390 }
 391
 392 sub T {
 393         my ($self, $m, $deletions) = @_;
 394
 395         # Work around subversion issue 4091: toggling the "is a
 396         # symlink" property requires removing and re-adding a
 397         # file or else "svn up" on affected clients trips an
 398         # assertion and aborts.
 399         if (($m->{mode_b} =~ /^120/ && $m->{mode_a} !~ /^120/) ||
 400             ($m->{mode_b} !~ /^120/ && $m->{mode_a} =~ /^120/)) {
 401                 $self->D({
 402                         mode_a => $m->{mode_a}, mode_b => '000000',
 403                         sha1_a => $m->{sha1_a}, sha1_b => '0' x 40,
 404                         chg => 'D', file_b => $m->{file_b}
 405                 }, $deletions);
 406                 $self->A({
 407                         mode_a => '000000', mode_b => $m->{mode_b},
 408                         sha1_a => '0' x 40, sha1_b => $m->{sha1_b},
 409                         chg => 'A', file_b => $m->{file_b}
 410                 }, $deletions);
 411                 return;
 412         }
 413
 414         $self->M($m, $deletions);
 415 }
 416
 417 sub change_file_prop {
 418         my ($self, $fbat, $pname, $pval) = @_;
 419         $self->SUPER::change_file_prop($fbat, $pname, $pval, $self->{pool});
 420 }
 421
 422 sub change_dir_prop {
 423         my ($self, $pbat, $pname, $pval) = @_;
 424         $self->SUPER::change_dir_prop($pbat, $pname, $pval, $self->{pool});
 425 }
 426
 427 sub _chg_file_get_blob ($$$$) {
 428         my ($self, $fbat, $m, $which) = @_;
 429         my $fh = $::_repository->temp_acquire("git_blob_$which");
 430         if ($m->{"mode_$which"} =~ /^120/) {
 431                 print $fh 'link ' or croak $!;
 432                 $self->change_file_prop($fbat,'svn:special','*');
 433         } elsif ($m->{mode_a} =~ /^120/ && $m->{"mode_$which"} !~ /^120/) {
 434                 $self->change_file_prop($fbat,'svn:special',undef);
 435         }
 436         my $blob = $m->{"sha1_$which"};
 437         return ($fh,) if ($blob =~ /^0{40}$/);
 438         my $size = $::_repository->cat_blob($blob, $fh);
 439         croak "Failed to read object $blob" if ($size < 0);
 440         $fh->flush == 0 or croak $!;
 441         seek $fh, 0, 0 or croak $!;
 442
 443         my $exp = ::md5sum($fh);
 444         seek $fh, 0, 0 or croak $!;
 445         return ($fh, $exp);
 446 }
 447
 448 sub chg_file {
 449         my ($self, $fbat, $m) = @_;
 450         if ($m->{mode_b} =~ /755$/ && $m->{mode_a} !~ /755$/) {
 451                 $self->change_file_prop($fbat,'svn:executable','*');
 452         } elsif ($m->{mode_b} !~ /755$/ && $m->{mode_a} =~ /755$/) {
 453                 $self->change_file_prop($fbat,'svn:executable',undef);
 454         }
 455         my ($fh_a, $exp_a) = _chg_file_get_blob $self, $fbat, $m, 'a';
 456         my ($fh_b, $exp_b) = _chg_file_get_blob $self, $fbat, $m, 'b';
 457         my $pool = SVN::Pool->new;
 458         my $atd = $self->apply_textdelta($fbat, $exp_a, $pool);
 459         if (-s $fh_a) {
 460                 my $txstream = SVN::TxDelta::new ($fh_a, $fh_b, $pool);
 461                 my $res = SVN::TxDelta::send_txstream($txstream, @$atd, $pool);
 462                 if (defined $res) {
 463                         die "Unexpected result from send_txstream: $res\n",
 464                             "(SVN::Core::VERSION: $SVN::Core::VERSION)\n";
 465                 }
 466         } else {
 467                 my $got = SVN::TxDelta::send_stream($fh_b, @$atd, $pool);
 468                 die "Checksum mismatch\nexpected: $exp_b\ngot: $got\n"
 469                     if ($got ne $exp_b);
 470         }
 471         Git::temp_release($fh_b, 1);
 472         Git::temp_release($fh_a, 1);
 473         $pool->clear;
 474 }
 475
 476 sub D {
 477         my ($self, $m, $deletions) = @_;
 478         my ($dir, $file) = split_path($m->{file_b});
 479         my $pbat = $self->ensure_path($dir, $deletions);
 480         print "\tD\t$m->{file_b}\n" unless $::_q;
 481         $self->delete_entry($m->{file_b}, $pbat);
 482 }
 483
 484 sub close_edit {
 485         my ($self) = @_;
 486         my ($p,$bat) = ($self->{pool}, $self->{bat});
 487         foreach (sort { $b =~ tr#/#/# <=> $a =~ tr#/#/# } keys %$bat) {
 488                 next if $_ eq '';
 489                 $self->close_directory($bat->{$_}, $p);
 490         }
 491         $self->close_directory($bat->{''}, $p);
 492         $self->SUPER::close_edit($p);
 493         $p->clear;
 494 }
 495
 496 sub abort_edit {
 497         my ($self) = @_;
 498         $self->SUPER::abort_edit($self->{pool});
 499 }
 500
 501 sub DESTROY {
 502         my $self = shift;
 503         $self->SUPER::DESTROY(@_);
 504         $self->{pool}->clear;
 505 }
 506
 507 # this drives the editor
 508 sub apply_diff {
 509         my ($self) = @_;
 510         my $mods = $self->{mods};
 511         my %o = ( D => 0, C => 1, R => 2, A => 3, M => 4, T => 5 );
 512         my %deletions;
 513
 514         foreach my $m (@$mods) {
 515                 if ($m->{chg} eq "D") {
 516                         $deletions{$m->{file_b}} = 1;
 517                 }
 518         }
 519
 520         foreach my $m (sort { $o{$a->{chg}} <=> $o{$b->{chg}} } @$mods) {
 521                 my $f = $m->{chg};
 522                 if (defined $o{$f}) {
 523                         $self->$f($m, \%deletions);
 524                 } else {
 525                         fatal("Invalid change type: $f");
 526                 }
 527         }
 528
 529         if (defined($self->{mergeinfo})) {
 530                 $self->change_dir_prop($self->{bat}{''}, "svn:mergeinfo",
 531                                        $self->{mergeinfo});
 532         }
 533         $self->rmdirs if $_rmdir;
 534         if (@$mods == 0 && !defined($self->{mergeinfo})) {
 535                 $self->abort_edit;
 536         } else {
 537                 $self->close_edit;
 538         }
 539         return scalar @$mods;
 540 }
 541
 542 1;
 543 __END__
 544
 545 =head1 NAME
 546
 547 Git::SVN::Editor - commit driver for "git svn set-tree" and dcommit
 548
 549 =head1 SYNOPSIS
 550
 551         use Git::SVN::Editor;
 552         use Git::SVN::Ra;
 553
 554         my $ra = Git::SVN::Ra->new($url);
 555         my %opts = (
 556                 r => 19,
 557                 log => "log message",
 558                 ra => $ra,
 559                 config => SVN::Core::config_get_config($svn_config_dir),
 560                 tree_a => "$commit^",
 561                 tree_b => "$commit",
 562                 editor_cb => sub { print "Committed r$_[0]\n"; },
 563                 mergeinfo => "/branches/foo:1-10",
 564                 svn_path => "trunk"
 565         );
 566         Git::SVN::Editor->new(\%opts)->apply_diff or print "No changes\n";
 567
 568         my $re = Git::SVN::Editor::glob2pat("trunk/*");
 569         if ($branchname =~ /$re/) {
 570                 print "matched!\n";
 571         }
 572
 573 =head1 DESCRIPTION
 574
 575 This module is an implementation detail of the "git svn" command.
 576 Do not use it unless you are developing git-svn.
 577
 578 This module adapts the C<SVN::Delta::Editor> object returned by
 579 C<SVN::Delta::get_commit_editor> and drives it to convey the
 580 difference between two git tree objects to a remote Subversion
 581 repository.
 582
 583 The interface will change as git-svn evolves.
 584
 585 =head1 DEPENDENCIES
 586
 587 Subversion perl bindings,
 588 the core L<Carp> module,
 589 and git's L<Git> helper module.
 590
 591 C<Git::SVN::Editor> has not been tested using callers other than
 592 B<git-svn> itself.
 593
 594 =head1 SEE ALSO
 595
 596 L<SVN::Delta>,
 597 L<Git::SVN::Fetcher>.
 598
 599 =head1 INCOMPATIBILITIES
 600
 601 None reported.
 602
 603 =head1 BUGS
 604
 605 None.