contrib/git-svn/git-svn.perl

   1 #!/usr/bin/env perl
   2 # Copyright (C) 2006, Eric Wong <normalperson@yhbt.net>
   3 # License: GPL v2 or later
   4 use warnings;
   5 use strict;
   6 use vars qw/    $AUTHOR $VERSION
   7                 $SVN_URL $SVN_INFO $SVN_WC $SVN_UUID
   8                 $GIT_SVN_INDEX $GIT_SVN
   9                 $GIT_DIR $REV_DIR/;
  10 $AUTHOR = 'Eric Wong <normalperson@yhbt.net>';
  11 $VERSION = '1.0.0';
  12
  13 use Cwd qw/abs_path/;
  14 $GIT_DIR = abs_path($ENV{GIT_DIR} || '.git');
  15 $ENV{GIT_DIR} = $GIT_DIR;
  16
  17 # make sure the svn binary gives consistent output between locales and TZs:
  18 $ENV{TZ} = 'UTC';
  19 $ENV{LC_ALL} = 'C';
  20
  21 # If SVN:: library support is added, please make the dependencies
  22 # optional and preserve the capability to use the command-line client.
  23 # use eval { require SVN::... } to make it lazy load
  24 # We don't use any modules not in the standard Perl distribution:
  25 use Carp qw/croak/;
  26 use IO::File qw//;
  27 use File::Basename qw/dirname basename/;
  28 use File::Path qw/mkpath/;
  29 use Getopt::Long qw/:config gnu_getopt no_ignore_case auto_abbrev/;
  30 use File::Spec qw//;
  31 use POSIX qw/strftime/;
  32 my $sha1 = qr/[a-f\d]{40}/;
  33 my $sha1_short = qr/[a-f\d]{4,40}/;
  34 my ($_revision,$_stdin,$_no_ignore_ext,$_no_stop_copy,$_help,$_rmdir,$_edit,
  35         $_find_copies_harder, $_l, $_version, $_upgrade, $_authors);
  36 my (@_branch_from, %tree_map, %users);
  37 my $_svn_co_url_revs;
  38
  39 my %fc_opts = ( 'no-ignore-externals' => \$_no_ignore_ext,
  40                 'branch|b=s' => \@_branch_from,
  41                 'authors-file|A=s' => \$_authors );
  42 my %cmd = (
  43         fetch => [ \&fetch, "Download new revisions from SVN",
  44                         { 'revision|r=s' => \$_revision, %fc_opts } ],
  45         init => [ \&init, "Initialize a repo for tracking" .
  46                           " (requires URL argument)", { } ],
  47         commit => [ \&commit, "Commit git revisions to SVN",
  48                         {       'stdin|' => \$_stdin,
  49                                 'edit|e' => \$_edit,
  50                                 'rmdir' => \$_rmdir,
  51                                 'find-copies-harder' => \$_find_copies_harder,
  52                                 'l=i' => \$_l,
  53                                 %fc_opts,
  54                         } ],
  55         'show-ignore' => [ \&show_ignore, "Show svn:ignore listings", { } ],
  56         rebuild => [ \&rebuild, "Rebuild git-svn metadata (after git clone)",
  57                         { 'no-ignore-externals' => \$_no_ignore_ext,
  58                           'upgrade' => \$_upgrade } ],
  59 );
  60 my $cmd;
  61 for (my $i = 0; $i < @ARGV; $i++) {
  62         if (defined $cmd{$ARGV[$i]}) {
  63                 $cmd = $ARGV[$i];
  64                 splice @ARGV, $i, 1;
  65                 last;
  66         }
  67 };
  68
  69 my %opts = %{$cmd{$cmd}->[2]} if (defined $cmd);
  70
  71 # convert GetOpt::Long specs for use by git-repo-config
  72 foreach my $o (keys %opts) {
  73         my $v = $opts{$o};
  74         my ($key) = ($o =~ /^([a-z\-]+)/);
  75         $key =~ s/-//g;
  76         my $arg = 'git-repo-config';
  77         $arg .= ' --int' if ($o =~ /=i$/);
  78         $arg .= ' --bool' if ($o !~ /=[sfi]$/);
  79         if (ref $v eq 'ARRAY') {
  80                 chomp(my @tmp = `$arg --get-all svn.$key`);
  81                 @$v = @tmp if @tmp;
  82         } else {
  83                 chomp(my $tmp = `$arg --get svn.$key`);
  84                 if ($tmp && !($arg =~ / --bool / && $tmp eq 'false')) {
  85                         $$v = $tmp;
  86                 }
  87         }
  88 }
  89
  90 GetOptions(%opts, 'help|H|h' => \$_help,
  91                 'version|V' => \$_version,
  92                 'id|i=s' => \$GIT_SVN) or exit 1;
  93
  94 $GIT_SVN ||= $ENV{GIT_SVN_ID} || 'git-svn';
  95 $GIT_SVN_INDEX = "$GIT_DIR/$GIT_SVN/index";
  96 $SVN_URL = undef;
  97 $REV_DIR = "$GIT_DIR/$GIT_SVN/revs";
  98 $SVN_WC = "$GIT_DIR/$GIT_SVN/tree";
  99
 100 usage(0) if $_help;
 101 version() if $_version;
 102 usage(1) unless defined $cmd;
 103 load_authors() if $_authors;
 104 svn_compat_check();
 105 $cmd{$cmd}->[0]->(@ARGV);
 106 exit 0;
 107
 108 ####################### primary functions ######################
 109 sub usage {
 110         my $exit = shift || 0;
 111         my $fd = $exit ? \*STDERR : \*STDOUT;
 112         print $fd <<"";
 113 git-svn - bidirectional operations between a single Subversion tree and git
 114 Usage: $0 <command> [options] [arguments]\n
 115
 116         print $fd "Available commands:\n" unless $cmd;
 117
 118         foreach (sort keys %cmd) {
 119                 next if $cmd && $cmd ne $_;
 120                 print $fd '  ',pack('A13',$_),$cmd{$_}->[1],"\n";
 121                 foreach (keys %{$cmd{$_}->[2]}) {
 122                         # prints out arguments as they should be passed:
 123                         my $x = s#=s$## ? '<arg>' : s#=i$## ? '<num>' : '';
 124                         print $fd ' ' x 17, join(', ', map { length $_ > 1 ?
 125                                                         "--$_" : "-$_" }
 126                                                 split /\|/,$_)," $x\n";
 127                 }
 128         }
 129         print $fd <<"";
 130 \nGIT_SVN_ID may be set in the environment or via the --id/-i switch to an
 131 arbitrary identifier if you're tracking multiple SVN branches/repositories in
 132 one git repository and want to keep them separate.  See git-svn(1) for more
 133 information.
 134
 135         exit $exit;
 136 }
 137
 138 sub version {
 139         print "git-svn version $VERSION\n";
 140         exit 0;
 141 }
 142
 143 sub rebuild {
 144         $SVN_URL = shift or undef;
 145         my $newest_rev = 0;
 146         if ($_upgrade) {
 147                 sys('git-update-ref',"refs/remotes/$GIT_SVN","$GIT_SVN-HEAD");
 148         } else {
 149                 check_upgrade_needed();
 150         }
 151
 152         my $pid = open(my $rev_list,'-|');
 153         defined $pid or croak $!;
 154         if ($pid == 0) {
 155                 exec("git-rev-list","refs/remotes/$GIT_SVN") or croak $!;
 156         }
 157         my $latest;
 158         while (<$rev_list>) {
 159                 chomp;
 160                 my $c = $_;
 161                 croak "Non-SHA1: $c\n" unless $c =~ /^$sha1$/o;
 162                 my @commit = grep(/^git-svn-id: /,`git-cat-file commit $c`);
 163                 next if (!@commit); # skip merges
 164                 my $id = $commit[$#commit];
 165                 my ($url, $rev, $uuid) = ($id =~ /^git-svn-id:\s(\S+?)\@(\d+)
 166                                                 \s([a-f\d\-]+)$/x);
 167                 if (!$rev || !$uuid || !$url) {
 168                         # some of the original repositories I made had
 169                         # indentifiers like this:
 170                         ($rev, $uuid) = ($id =~/^git-svn-id:\s(\d+)
 171                                                         \@([a-f\d\-]+)/x);
 172                         if (!$rev || !$uuid) {
 173                                 croak "Unable to extract revision or UUID from ",
 174                                         "$c, $id\n";
 175                         }
 176                 }
 177
 178                 # if we merged or otherwise started elsewhere, this is
 179                 # how we break out of it
 180                 next if (defined $SVN_UUID && ($uuid ne $SVN_UUID));
 181                 next if (defined $SVN_URL && defined $url && ($url ne $SVN_URL));
 182
 183                 print "r$rev = $c\n";
 184                 unless (defined $latest) {
 185                         if (!$SVN_URL && !$url) {
 186                                 croak "SVN repository location required: $url\n";
 187                         }
 188                         $SVN_URL ||= $url;
 189                         $SVN_UUID ||= $uuid;
 190                         setup_git_svn();
 191                         $latest = $rev;
 192                 }
 193                 assert_revision_eq_or_unknown($rev, $c);
 194                 sys('git-update-ref',"$GIT_SVN/revs/$rev",$c);
 195                 $newest_rev = $rev if ($rev > $newest_rev);
 196         }
 197         close $rev_list or croak $?;
 198         if (!chdir $SVN_WC) {
 199                 svn_cmd_checkout($SVN_URL, $latest, $SVN_WC);
 200                 chdir $SVN_WC or croak $!;
 201         }
 202
 203         $pid = fork;
 204         defined $pid or croak $!;
 205         if ($pid == 0) {
 206                 my @svn_up = qw(svn up);
 207                 push @svn_up, '--ignore-externals' unless $_no_ignore_ext;
 208                 sys(@svn_up,"-r$newest_rev");
 209                 $ENV{GIT_INDEX_FILE} = $GIT_SVN_INDEX;
 210                 git_addremove();
 211                 exec('git-write-tree');
 212         }
 213         waitpid $pid, 0;
 214
 215         if ($_upgrade) {
 216                 print STDERR <<"";
 217 Keeping deprecated refs/head/$GIT_SVN-HEAD for now.  Please remove it
 218 when you have upgraded your tools and habits to use refs/remotes/$GIT_SVN
 219
 220         }
 221 }
 222
 223 sub init {
 224         $SVN_URL = shift or die "SVN repository location required " .
 225                                 "as a command-line argument\n";
 226         unless (-d $GIT_DIR) {
 227                 sys('git-init-db');
 228         }
 229         setup_git_svn();
 230 }
 231
 232 sub fetch {
 233         my (@parents) = @_;
 234         check_upgrade_needed();
 235         $SVN_URL ||= file_to_s("$GIT_DIR/$GIT_SVN/info/url");
 236         my @log_args = -d $SVN_WC ? ($SVN_WC) : ($SVN_URL);
 237         unless ($_revision) {
 238                 $_revision = -d $SVN_WC ? 'BASE:HEAD' : '0:HEAD';
 239         }
 240         push @log_args, "-r$_revision";
 241         push @log_args, '--stop-on-copy' unless $_no_stop_copy;
 242
 243         my $svn_log = svn_log_raw(@log_args);
 244
 245         my $base = next_log_entry($svn_log) or croak "No base revision!\n";
 246         my $last_commit = undef;
 247         unless (-d $SVN_WC) {
 248                 svn_cmd_checkout($SVN_URL,$base->{revision},$SVN_WC);
 249                 chdir $SVN_WC or croak $!;
 250                 read_uuid();
 251                 $last_commit = git_commit($base, @parents);
 252                 assert_svn_wc_clean($base->{revision}, $last_commit);
 253         } else {
 254                 chdir $SVN_WC or croak $!;
 255                 read_uuid();
 256                 $last_commit = file_to_s("$REV_DIR/$base->{revision}");
 257         }
 258         my @svn_up = qw(svn up);
 259         push @svn_up, '--ignore-externals' unless $_no_ignore_ext;
 260         my $last = $base;
 261         while (my $log_msg = next_log_entry($svn_log)) {
 262                 assert_svn_wc_clean($last->{revision}, $last_commit);
 263                 if ($last->{revision} >= $log_msg->{revision}) {
 264                         croak "Out of order: last >= current: ",
 265                                 "$last->{revision} >= $log_msg->{revision}\n";
 266                 }
 267                 sys(@svn_up,"-r$log_msg->{revision}");
 268                 $last_commit = git_commit($log_msg, $last_commit, @parents);
 269                 $last = $log_msg;
 270         }
 271         assert_svn_wc_clean($last->{revision}, $last_commit);
 272         unless (-e "$GIT_DIR/refs/heads/master") {
 273                 sys(qw(git-update-ref refs/heads/master),$last_commit);
 274         }
 275         return $last;
 276 }
 277
 278 sub commit {
 279         my (@commits) = @_;
 280         check_upgrade_needed();
 281         if ($_stdin || !@commits) {
 282                 print "Reading from stdin...\n";
 283                 @commits = ();
 284                 while (<STDIN>) {
 285                         if (/\b($sha1_short)\b/o) {
 286                                 unshift @commits, $1;
 287                         }
 288                 }
 289         }
 290         my @revs;
 291         foreach my $c (@commits) {
 292                 chomp(my @tmp = safe_qx('git-rev-parse',$c));
 293                 if (scalar @tmp == 1) {
 294                         push @revs, $tmp[0];
 295                 } elsif (scalar @tmp > 1) {
 296                         push @revs, reverse (safe_qx('git-rev-list',@tmp));
 297                 } else {
 298                         die "Failed to rev-parse $c\n";
 299                 }
 300         }
 301         chomp @revs;
 302
 303         fetch();
 304         chdir $SVN_WC or croak $!;
 305         my $info = svn_info('.');
 306         read_uuid($info);
 307         my $svn_current_rev =  $info->{'Last Changed Rev'};
 308         foreach my $c (@revs) {
 309                 my $mods = svn_checkout_tree($svn_current_rev, $c);
 310                 if (scalar @$mods == 0) {
 311                         print "Skipping, no changes detected\n";
 312                         next;
 313                 }
 314                 $svn_current_rev = svn_commit_tree($svn_current_rev, $c);
 315         }
 316         print "Done committing ",scalar @revs," revisions to SVN\n";
 317
 318 }
 319
 320 sub show_ignore {
 321         require File::Find or die $!;
 322         my $exclude_file = "$GIT_DIR/info/exclude";
 323         open my $fh, '<', $exclude_file or croak $!;
 324         chomp(my @excludes = (<$fh>));
 325         close $fh or croak $!;
 326
 327         $SVN_URL ||= file_to_s("$GIT_DIR/$GIT_SVN/info/url");
 328         chdir $SVN_WC or croak $!;
 329         my %ign;
 330         File::Find::find({wanted=>sub{if(lstat $_ && -d _ && -d "$_/.svn"){
 331                 s#^\./##;
 332                 @{$ign{$_}} = safe_qx(qw(svn propget svn:ignore),$_);
 333                 }}, no_chdir=>1},'.');
 334
 335         print "\n# /\n";
 336         foreach (@{$ign{'.'}}) { print '/',$_ if /\S/ }
 337         delete $ign{'.'};
 338         foreach my $i (sort keys %ign) {
 339                 print "\n# ",$i,"\n";
 340                 foreach (@{$ign{$i}}) { print '/',$i,'/',$_ if /\S/ }
 341         }
 342 }
 343
 344 ########################### utility functions #########################
 345
 346 sub read_uuid {
 347         return if $SVN_UUID;
 348         my $info = shift || svn_info('.');
 349         $SVN_UUID = $info->{'Repository UUID'} or
 350                                         croak "Repository UUID unreadable\n";
 351         s_to_file($SVN_UUID,"$GIT_DIR/$GIT_SVN/info/uuid");
 352 }
 353
 354 sub setup_git_svn {
 355         defined $SVN_URL or croak "SVN repository location required\n";
 356         unless (-d $GIT_DIR) {
 357                 croak "GIT_DIR=$GIT_DIR does not exist!\n";
 358         }
 359         mkpath(["$GIT_DIR/$GIT_SVN"]);
 360         mkpath(["$GIT_DIR/$GIT_SVN/info"]);
 361         mkpath([$REV_DIR]);
 362         s_to_file($SVN_URL,"$GIT_DIR/$GIT_SVN/info/url");
 363
 364         open my $fd, '>>', "$GIT_DIR/$GIT_SVN/info/exclude" or croak $!;
 365         print $fd '.svn',"\n";
 366         close $fd or croak $!;
 367 }
 368
 369 sub assert_svn_wc_clean {
 370         my ($svn_rev, $treeish) = @_;
 371         croak "$svn_rev is not an integer!\n" unless ($svn_rev =~ /^\d+$/);
 372         croak "$treeish is not a sha1!\n" unless ($treeish =~ /^$sha1$/o);
 373         my $lcr = svn_info('.')->{'Last Changed Rev'};
 374         if ($svn_rev != $lcr) {
 375                 print STDERR "Checking for copy-tree ... ";
 376                 # use
 377                 my @diff = grep(/^Index: /,(safe_qx(qw(svn diff),
 378                                                 "-r$lcr:$svn_rev")));
 379                 if (@diff) {
 380                         croak "Nope!  Expected r$svn_rev, got r$lcr\n";
 381                 } else {
 382                         print STDERR "OK!\n";
 383                 }
 384         }
 385         my @status = grep(!/^Performing status on external/,(`svn status`));
 386         @status = grep(!/^\s*$/,@status);
 387         if (scalar @status) {
 388                 print STDERR "Tree ($SVN_WC) is not clean:\n";
 389                 print STDERR $_ foreach @status;
 390                 croak;
 391         }
 392         assert_tree($treeish);
 393 }
 394
 395 sub assert_tree {
 396         my ($treeish) = @_;
 397         croak "Not a sha1: $treeish\n" unless $treeish =~ /^$sha1$/o;
 398         chomp(my $type = `git-cat-file -t $treeish`);
 399         my $expected;
 400         while ($type eq 'tag') {
 401                 chomp(($treeish, $type) = `git-cat-file tag $treeish`);
 402         }
 403         if ($type eq 'commit') {
 404                 $expected = (grep /^tree /,`git-cat-file commit $treeish`)[0];
 405                 ($expected) = ($expected =~ /^tree ($sha1)$/);
 406                 die "Unable to get tree from $treeish\n" unless $expected;
 407         } elsif ($type eq 'tree') {
 408                 $expected = $treeish;
 409         } else {
 410                 die "$treeish is a $type, expected tree, tag or commit\n";
 411         }
 412
 413         my $old_index = $ENV{GIT_INDEX_FILE};
 414         my $tmpindex = $GIT_SVN_INDEX.'.assert-tmp';
 415         if (-e $tmpindex) {
 416                 unlink $tmpindex or croak $!;
 417         }
 418         $ENV{GIT_INDEX_FILE} = $tmpindex;
 419         git_addremove();
 420         chomp(my $tree = `git-write-tree`);
 421         if ($old_index) {
 422                 $ENV{GIT_INDEX_FILE} = $old_index;
 423         } else {
 424                 delete $ENV{GIT_INDEX_FILE};
 425         }
 426         if ($tree ne $expected) {
 427                 croak "Tree mismatch, Got: $tree, Expected: $expected\n";
 428         }
 429 }
 430
 431 sub parse_diff_tree {
 432         my $diff_fh = shift;
 433         local $/ = "\0";
 434         my $state = 'meta';
 435         my @mods;
 436         while (<$diff_fh>) {
 437                 chomp $_; # this gets rid of the trailing "\0"
 438                 if ($state eq 'meta' && /^:(\d{6})\s(\d{6})\s
 439                                         $sha1\s($sha1)\s([MTCRAD])\d*$/xo) {
 440                         push @mods, {   mode_a => $1, mode_b => $2,
 441                                         sha1_b => $3, chg => $4 };
 442                         if ($4 =~ /^(?:C|R)$/) {
 443                                 $state = 'file_a';
 444                         } else {
 445                                 $state = 'file_b';
 446                         }
 447                 } elsif ($state eq 'file_a') {
 448                         my $x = $mods[$#mods] or croak "Empty array\n";
 449                         if ($x->{chg} !~ /^(?:C|R)$/) {
 450                                 croak "Error parsing $_, $x->{chg}\n";
 451                         }
 452                         $x->{file_a} = $_;
 453                         $state = 'file_b';
 454                 } elsif ($state eq 'file_b') {
 455                         my $x = $mods[$#mods] or croak "Empty array\n";
 456                         if (exists $x->{file_a} && $x->{chg} !~ /^(?:C|R)$/) {
 457                                 croak "Error parsing $_, $x->{chg}\n";
 458                         }
 459                         if (!exists $x->{file_a} && $x->{chg} =~ /^(?:C|R)$/) {
 460                                 croak "Error parsing $_, $x->{chg}\n";
 461                         }
 462                         $x->{file_b} = $_;
 463                         $state = 'meta';
 464                 } else {
 465                         croak "Error parsing $_\n";
 466                 }
 467         }
 468         close $diff_fh or croak $!;
 469
 470         return \@mods;
 471 }
 472
 473 sub svn_check_prop_executable {
 474         my $m = shift;
 475         return if -l $m->{file_b};
 476         if ($m->{mode_b} =~ /755$/) {
 477                 chmod((0755 &~ umask),$m->{file_b}) or croak $!;
 478                 if ($m->{mode_a} !~ /755$/) {
 479                         sys(qw(svn propset svn:executable 1), $m->{file_b});
 480                 }
 481                 -x $m->{file_b} or croak "$m->{file_b} is not executable!\n";
 482         } elsif ($m->{mode_b} !~ /755$/ && $m->{mode_a} =~ /755$/) {
 483                 sys(qw(svn propdel svn:executable), $m->{file_b});
 484                 chmod((0644 &~ umask),$m->{file_b}) or croak $!;
 485                 -x $m->{file_b} and croak "$m->{file_b} is executable!\n";
 486         }
 487 }
 488
 489 sub svn_ensure_parent_path {
 490         my $dir_b = dirname(shift);
 491         svn_ensure_parent_path($dir_b) if ($dir_b ne File::Spec->curdir);
 492         mkpath([$dir_b]) unless (-d $dir_b);
 493         sys(qw(svn add -N), $dir_b) unless (-d "$dir_b/.svn");
 494 }
 495
 496 sub precommit_check {
 497         my $mods = shift;
 498         my (%rm_file, %rmdir_check, %added_check);
 499
 500         my %o = ( D => 0, R => 1, C => 2, A => 3, M => 3, T => 3 );
 501         foreach my $m (sort { $o{$a->{chg}} <=> $o{$b->{chg}} } @$mods) {
 502                 if ($m->{chg} eq 'R') {
 503                         if (-d $m->{file_b}) {
 504                                 err_dir_to_file("$m->{file_a} => $m->{file_b}");
 505                         }
 506                         # dir/$file => dir/file/$file
 507                         my $dirname = dirname($m->{file_b});
 508                         while ($dirname ne File::Spec->curdir) {
 509                                 if ($dirname ne $m->{file_a}) {
 510                                         $dirname = dirname($dirname);
 511                                         next;
 512                                 }
 513                                 err_file_to_dir("$m->{file_a} => $m->{file_b}");
 514                         }
 515                         # baz/zzz => baz (baz is a file)
 516                         $dirname = dirname($m->{file_a});
 517                         while ($dirname ne File::Spec->curdir) {
 518                                 if ($dirname ne $m->{file_b}) {
 519                                         $dirname = dirname($dirname);
 520                                         next;
 521                                 }
 522                                 err_dir_to_file("$m->{file_a} => $m->{file_b}");
 523                         }
 524                 }
 525                 if ($m->{chg} =~ /^(D|R)$/) {
 526                         my $t = $1 eq 'D' ? 'file_b' : 'file_a';
 527                         $rm_file{ $m->{$t} } = 1;
 528                         my $dirname = dirname( $m->{$t} );
 529                         my $basename = basename( $m->{$t} );
 530                         $rmdir_check{$dirname}->{$basename} = 1;
 531                 } elsif ($m->{chg} =~ /^(?:A|C)$/) {
 532                         if (-d $m->{file_b}) {
 533                                 err_dir_to_file($m->{file_b});
 534                         }
 535                         my $dirname = dirname( $m->{file_b} );
 536                         my $basename = basename( $m->{file_b} );
 537                         $added_check{$dirname}->{$basename} = 1;
 538                         while ($dirname ne File::Spec->curdir) {
 539                                 if ($rm_file{$dirname}) {
 540                                         err_file_to_dir($m->{file_b});
 541                                 }
 542                                 $dirname = dirname $dirname;
 543                         }
 544                 }
 545         }
 546         return (\%rmdir_check, \%added_check);
 547
 548         sub err_dir_to_file {
 549                 my $file = shift;
 550                 print STDERR "Node change from directory to file ",
 551                                 "is not supported by Subversion: ",$file,"\n";
 552                 exit 1;
 553         }
 554         sub err_file_to_dir {
 555                 my $file = shift;
 556                 print STDERR "Node change from file to directory ",
 557                                 "is not supported by Subversion: ",$file,"\n";
 558                 exit 1;
 559         }
 560 }
 561
 562 sub svn_checkout_tree {
 563         my ($svn_rev, $treeish) = @_;
 564         my $from = file_to_s("$REV_DIR/$svn_rev");
 565         assert_svn_wc_clean($svn_rev,$from);
 566         print "diff-tree $from $treeish\n";
 567         my $pid = open my $diff_fh, '-|';
 568         defined $pid or croak $!;
 569         if ($pid == 0) {
 570                 my @diff_tree = qw(git-diff-tree -z -r -C);
 571                 push @diff_tree, '--find-copies-harder' if $_find_copies_harder;
 572                 push @diff_tree, "-l$_l" if defined $_l;
 573                 exec(@diff_tree, $from, $treeish) or croak $!;
 574         }
 575         my $mods = parse_diff_tree($diff_fh);
 576         unless (@$mods) {
 577                 # git can do empty commits, but SVN doesn't allow it...
 578                 return $mods;
 579         }
 580         my ($rm, $add) = precommit_check($mods);
 581
 582         my %o = ( D => 1, R => 0, C => -1, A => 3, M => 3, T => 3 );
 583         foreach my $m (sort { $o{$a->{chg}} <=> $o{$b->{chg}} } @$mods) {
 584                 if ($m->{chg} eq 'C') {
 585                         svn_ensure_parent_path( $m->{file_b} );
 586                         sys(qw(svn cp),         $m->{file_a}, $m->{file_b});
 587                         apply_mod_line_blob($m);
 588                         svn_check_prop_executable($m);
 589                 } elsif ($m->{chg} eq 'D') {
 590                         sys(qw(svn rm --force), $m->{file_b});
 591                 } elsif ($m->{chg} eq 'R') {
 592                         svn_ensure_parent_path( $m->{file_b} );
 593                         sys(qw(svn mv --force), $m->{file_a}, $m->{file_b});
 594                         apply_mod_line_blob($m);
 595                         svn_check_prop_executable($m);
 596                 } elsif ($m->{chg} eq 'M') {
 597                         apply_mod_line_blob($m);
 598                         svn_check_prop_executable($m);
 599                 } elsif ($m->{chg} eq 'T') {
 600                         sys(qw(svn rm --force),$m->{file_b});
 601                         apply_mod_line_blob($m);
 602                         sys(qw(svn add --force), $m->{file_b});
 603                         svn_check_prop_executable($m);
 604                 } elsif ($m->{chg} eq 'A') {
 605                         svn_ensure_parent_path( $m->{file_b} );
 606                         apply_mod_line_blob($m);
 607                         sys(qw(svn add --force), $m->{file_b});
 608                         svn_check_prop_executable($m);
 609                 } else {
 610                         croak "Invalid chg: $m->{chg}\n";
 611                 }
 612         }
 613
 614         assert_tree($treeish);
 615         if ($_rmdir) { # remove empty directories
 616                 handle_rmdir($rm, $add);
 617         }
 618         assert_tree($treeish);
 619         return $mods;
 620 }
 621
 622 # svn ls doesn't work with respect to the current working tree, but what's
 623 # in the repository.  There's not even an option for it... *sigh*
 624 # (added files don't show up and removed files remain in the ls listing)
 625 sub svn_ls_current {
 626         my ($dir, $rm, $add) = @_;
 627         chomp(my @ls = safe_qx('svn','ls',$dir));
 628         my @ret = ();
 629         foreach (@ls) {
 630                 s#/$##; # trailing slashes are evil
 631                 push @ret, $_ unless $rm->{$dir}->{$_};
 632         }
 633         if (exists $add->{$dir}) {
 634                 push @ret, keys %{$add->{$dir}};
 635         }
 636         return \@ret;
 637 }
 638
 639 sub handle_rmdir {
 640         my ($rm, $add) = @_;
 641
 642         foreach my $dir (sort {length $b <=> length $a} keys %$rm) {
 643                 my $ls = svn_ls_current($dir, $rm, $add);
 644                 next if (scalar @$ls);
 645                 sys(qw(svn rm --force),$dir);
 646
 647                 my $dn = dirname $dir;
 648                 $rm->{ $dn }->{ basename $dir } = 1;
 649                 $ls = svn_ls_current($dn, $rm, $add);
 650                 while (scalar @$ls == 0 && $dn ne File::Spec->curdir) {
 651                         sys(qw(svn rm --force),$dn);
 652                         $dir = basename $dn;
 653                         $dn = dirname $dn;
 654                         $rm->{ $dn }->{ $dir } = 1;
 655                         $ls = svn_ls_current($dn, $rm, $add);
 656                 }
 657         }
 658 }
 659
 660 sub svn_commit_tree {
 661         my ($svn_rev, $commit) = @_;
 662         my $commit_msg = "$GIT_DIR/$GIT_SVN/.svn-commit.tmp.$$";
 663         my %log_msg = ( msg => '' );
 664         open my $msg, '>', $commit_msg or croak $!;
 665
 666         chomp(my $type = `git-cat-file -t $commit`);
 667         if ($type eq 'commit') {
 668                 my $pid = open my $msg_fh, '-|';
 669                 defined $pid or croak $!;
 670
 671                 if ($pid == 0) {
 672                         exec(qw(git-cat-file commit), $commit) or croak $!;
 673                 }
 674                 my $in_msg = 0;
 675                 while (<$msg_fh>) {
 676                         if (!$in_msg) {
 677                                 $in_msg = 1 if (/^\s*$/);
 678                         } elsif (/^git-svn-id: /) {
 679                                 # skip this, we regenerate the correct one
 680                                 # on re-fetch anyways
 681                         } else {
 682                                 print $msg $_ or croak $!;
 683                         }
 684                 }
 685                 close $msg_fh or croak $!;
 686         }
 687         close $msg or croak $!;
 688
 689         if ($_edit || ($type eq 'tree')) {
 690                 my $editor = $ENV{VISUAL} || $ENV{EDITOR} || 'vi';
 691                 system($editor, $commit_msg);
 692         }
 693
 694         # file_to_s removes all trailing newlines, so just use chomp() here:
 695         open $msg, '<', $commit_msg or croak $!;
 696         { local $/; chomp($log_msg{msg} = <$msg>); }
 697         close $msg or croak $!;
 698
 699         my ($oneline) = ($log_msg{msg} =~ /([^\n\r]+)/);
 700         print "Committing $commit: $oneline\n";
 701
 702         my @ci_output = safe_qx(qw(svn commit -F),$commit_msg);
 703         my ($committed) = grep(/^Committed revision \d+\./,@ci_output);
 704         unlink $commit_msg;
 705         defined $committed or croak
 706                         "Commit output failed to parse committed revision!\n",
 707                         join("\n",@ci_output),"\n";
 708         my ($rev_committed) = ($committed =~ /^Committed revision (\d+)\./);
 709
 710         my @svn_up = qw(svn up);
 711         push @svn_up, '--ignore-externals' unless $_no_ignore_ext;
 712         if ($rev_committed == ($svn_rev + 1)) {
 713                 push @svn_up, "-r$rev_committed";
 714                 sys(@svn_up);
 715                 my $info = svn_info('.');
 716                 my $date = $info->{'Last Changed Date'} or die "Missing date\n";
 717                 if ($info->{'Last Changed Rev'} != $rev_committed) {
 718                         croak "$info->{'Last Changed Rev'} != $rev_committed\n"
 719                 }
 720                 my ($Y,$m,$d,$H,$M,$S,$tz) = ($date =~
 721                                         /(\d{4})\-(\d\d)\-(\d\d)\s
 722                                          (\d\d)\:(\d\d)\:(\d\d)\s([\-\+]\d+)/x)
 723                                          or croak "Failed to parse date: $date\n";
 724                 $log_msg{date} = "$tz $Y-$m-$d $H:$M:$S";
 725                 $log_msg{author} = $info->{'Last Changed Author'};
 726                 $log_msg{revision} = $rev_committed;
 727                 $log_msg{msg} .= "\n";
 728                 my $parent = file_to_s("$REV_DIR/$svn_rev");
 729                 git_commit(\%log_msg, $parent, $commit);
 730                 return $rev_committed;
 731         }
 732         # resync immediately
 733         push @svn_up, "-r$svn_rev";
 734         sys(@svn_up);
 735         return fetch("$rev_committed=$commit")->{revision};
 736 }
 737
 738 # read the entire log into a temporary file (which is removed ASAP)
 739 # and store the file handle + parser state
 740 sub svn_log_raw {
 741         my (@log_args) = @_;
 742         my $log_fh = IO::File->new_tmpfile or croak $!;
 743         my $pid = fork;
 744         defined $pid or croak $!;
 745         if (!$pid) {
 746                 open STDOUT, '>&', $log_fh or croak $!;
 747                 exec (qw(svn log), @log_args) or croak $!
 748         }
 749         waitpid $pid, 0;
 750         croak if $?;
 751         seek $log_fh, 0, 0 or croak $!;
 752         return { state => 'sep', fh => $log_fh };
 753 }
 754
 755 sub next_log_entry {
 756         my $log = shift; # retval of svn_log_raw()
 757         my $ret = undef;
 758         my $fh = $log->{fh};
 759
 760         while (<$fh>) {
 761                 chomp;
 762                 if (/^\-{72}$/) {
 763                         if ($log->{state} eq 'msg') {
 764                                 if ($ret->{lines}) {
 765                                         $ret->{msg} .= $_."\n";
 766                                         unless(--$ret->{lines}) {
 767                                                 $log->{state} = 'sep';
 768                                         }
 769                                 } else {
 770                                         croak "Log parse error at: $_\n",
 771                                                 $ret->{revision},
 772                                                 "\n";
 773                                 }
 774                                 next;
 775                         }
 776                         if ($log->{state} ne 'sep') {
 777                                 croak "Log parse error at: $_\n",
 778                                         "state: $log->{state}\n",
 779                                         $ret->{revision},
 780                                         "\n";
 781                         }
 782                         $log->{state} = 'rev';
 783
 784                         # if we have an empty log message, put something there:
 785                         if ($ret) {
 786                                 $ret->{msg} ||= "\n";
 787                                 delete $ret->{lines};
 788                                 return $ret;
 789                         }
 790                         next;
 791                 }
 792                 if ($log->{state} eq 'rev' && s/^r(\d+)\s*\|\s*//) {
 793                         my $rev = $1;
 794                         my ($author, $date, $lines) = split(/\s*\|\s*/, $_, 3);
 795                         ($lines) = ($lines =~ /(\d+)/);
 796                         my ($Y,$m,$d,$H,$M,$S,$tz) = ($date =~
 797                                         /(\d{4})\-(\d\d)\-(\d\d)\s
 798                                          (\d\d)\:(\d\d)\:(\d\d)\s([\-\+]\d+)/x)
 799                                          or croak "Failed to parse date: $date\n";
 800                         $ret = {        revision => $rev,
 801                                         date => "$tz $Y-$m-$d $H:$M:$S",
 802                                         author => $author,
 803                                         lines => $lines,
 804                                         msg => '' };
 805                         if (defined $_authors && ! defined $users{$author}) {
 806                                 die "Author: $author not defined in ",
 807                                                 "$_authors file\n";
 808                         }
 809                         $log->{state} = 'msg_start';
 810                         next;
 811                 }
 812                 # skip the first blank line of the message:
 813                 if ($log->{state} eq 'msg_start' && /^$/) {
 814                         $log->{state} = 'msg';
 815                 } elsif ($log->{state} eq 'msg') {
 816                         if ($ret->{lines}) {
 817                                 $ret->{msg} .= $_."\n";
 818                                 unless (--$ret->{lines}) {
 819                                         $log->{state} = 'sep';
 820                                 }
 821                         } else {
 822                                 croak "Log parse error at: $_\n",
 823                                         $ret->{revision},"\n";
 824                         }
 825                 }
 826         }
 827         return $ret;
 828 }
 829
 830 sub svn_info {
 831         my $url = shift || $SVN_URL;
 832
 833         my $pid = open my $info_fh, '-|';
 834         defined $pid or croak $!;
 835
 836         if ($pid == 0) {
 837                 exec(qw(svn info),$url) or croak $!;
 838         }
 839
 840         my $ret = {};
 841         # only single-lines seem to exist in svn info output
 842         while (<$info_fh>) {
 843                 chomp $_;
 844                 if (m#^([^:]+)\s*:\s*(\S.*)$#) {
 845                         $ret->{$1} = $2;
 846                         push @{$ret->{-order}}, $1;
 847                 }
 848         }
 849         close $info_fh or croak $!;
 850         return $ret;
 851 }
 852
 853 sub sys { system(@_) == 0 or croak $? }
 854
 855 sub git_addremove {
 856         system( "git-diff-files --name-only -z ".
 857                                 " | git-update-index --remove -z --stdin && ".
 858                 "git-ls-files -z --others ".
 859                         "'--exclude-from=$GIT_DIR/$GIT_SVN/info/exclude'".
 860                                 " | git-update-index --add -z --stdin"
 861                 ) == 0 or croak $?
 862 }
 863
 864 sub s_to_file {
 865         my ($str, $file, $mode) = @_;
 866         open my $fd,'>',$file or croak $!;
 867         print $fd $str,"\n" or croak $!;
 868         close $fd or croak $!;
 869         chmod ($mode &~ umask, $file) if (defined $mode);
 870 }
 871
 872 sub file_to_s {
 873         my $file = shift;
 874         open my $fd,'<',$file or croak "$!: file: $file\n";
 875         local $/;
 876         my $ret = <$fd>;
 877         close $fd or croak $!;
 878         $ret =~ s/\s*$//s;
 879         return $ret;
 880 }
 881
 882 sub assert_revision_unknown {
 883         my $revno = shift;
 884         if (-f "$REV_DIR/$revno") {
 885                 croak "$REV_DIR/$revno already exists! ",
 886                                 "Why are we refetching it?";
 887         }
 888 }
 889
 890 sub trees_eq {
 891         my ($x, $y) = @_;
 892         my @x = safe_qx('git-cat-file','commit',$x);
 893         my @y = safe_qx('git-cat-file','commit',$y);
 894         if (($y[0] ne $x[0]) || $x[0] !~ /^tree $sha1\n$/
 895                                 || $y[0] !~ /^tree $sha1\n$/) {
 896                 print STDERR "Trees not equal: $y[0] != $x[0]\n";
 897                 return 0
 898         }
 899         return 1;
 900 }
 901
 902 sub assert_revision_eq_or_unknown {
 903         my ($revno, $commit) = @_;
 904         if (-f "$REV_DIR/$revno") {
 905                 my $current = file_to_s("$REV_DIR/$revno");
 906                 if (($commit ne $current) && !trees_eq($commit, $current)) {
 907                         croak "$REV_DIR/$revno already exists!\n",
 908                                 "current: $current\nexpected: $commit\n";
 909                 }
 910                 return;
 911         }
 912 }
 913
 914 sub git_commit {
 915         my ($log_msg, @parents) = @_;
 916         assert_revision_unknown($log_msg->{revision});
 917         my $out_fh = IO::File->new_tmpfile or croak $!;
 918
 919         map_tree_joins() if (@_branch_from && !%tree_map);
 920
 921         # commit parents can be conditionally bound to a particular
 922         # svn revision via: "svn_revno=commit_sha1", filter them out here:
 923         my @exec_parents;
 924         foreach my $p (@parents) {
 925                 next unless defined $p;
 926                 if ($p =~ /^(\d+)=($sha1_short)$/o) {
 927                         if ($1 == $log_msg->{revision}) {
 928                                 push @exec_parents, $2;
 929                         }
 930                 } else {
 931                         push @exec_parents, $p if $p =~ /$sha1_short/o;
 932                 }
 933         }
 934
 935         my $pid = fork;
 936         defined $pid or croak $!;
 937         if ($pid == 0) {
 938                 $ENV{GIT_INDEX_FILE} = $GIT_SVN_INDEX;
 939                 git_addremove();
 940                 chomp(my $tree = `git-write-tree`);
 941                 croak if $?;
 942                 if (exists $tree_map{$tree}) {
 943                         my %seen_parent = map { $_ => 1 } @exec_parents;
 944                         foreach (@{$tree_map{$tree}}) {
 945                                 # MAXPARENT is defined to 16 in commit-tree.c:
 946                                 if ($seen_parent{$_} || @exec_parents > 16) {
 947                                         next;
 948                                 }
 949                                 push @exec_parents, $_;
 950                                 $seen_parent{$_} = 1;
 951                         }
 952                 }
 953                 my $msg_fh = IO::File->new_tmpfile or croak $!;
 954                 print $msg_fh $log_msg->{msg}, "\ngit-svn-id: ",
 955                                         "$SVN_URL\@$log_msg->{revision}",
 956                                         " $SVN_UUID\n" or croak $!;
 957                 $msg_fh->flush == 0 or croak $!;
 958                 seek $msg_fh, 0, 0 or croak $!;
 959
 960                 set_commit_env($log_msg);
 961
 962                 my @exec = ('git-commit-tree',$tree);
 963                 push @exec, '-p', $_  foreach @exec_parents;
 964                 open STDIN, '<&', $msg_fh or croak $!;
 965                 open STDOUT, '>&', $out_fh or croak $!;
 966                 exec @exec or croak $!;
 967         }
 968         waitpid($pid,0);
 969         croak if $?;
 970
 971         $out_fh->flush == 0 or croak $!;
 972         seek $out_fh, 0, 0 or croak $!;
 973         chomp(my $commit = do { local $/; <$out_fh> });
 974         if ($commit !~ /^$sha1$/o) {
 975                 croak "Failed to commit, invalid sha1: $commit\n";
 976         }
 977         my @update_ref = ('git-update-ref',"refs/remotes/$GIT_SVN",$commit);
 978         if (my $primary_parent = shift @exec_parents) {
 979                 $pid = fork;
 980                 defined $pid or croak $!;
 981                 if (!$pid) {
 982                         close STDERR;
 983                         close STDOUT;
 984                         exec 'git-rev-parse','--verify',
 985                                                 "refs/remotes/$GIT_SVN^0";
 986                 }
 987                 waitpid $pid, 0;
 988                 push @update_ref, $primary_parent unless $?;
 989         }
 990         sys(@update_ref);
 991         sys('git-update-ref',"$GIT_SVN/revs/$log_msg->{revision}",$commit);
 992         print "r$log_msg->{revision} = $commit\n";
 993         return $commit;
 994 }
 995
 996 sub set_commit_env {
 997         my ($log_msg) = @_;
 998         my $author = $log_msg->{author};
 999         my ($name,$email) = defined $users{$author} ?  @{$users{$author}}
1000                                 : ($author,"$author\@$SVN_UUID");
1001         $ENV{GIT_AUTHOR_NAME} = $ENV{GIT_COMMITTER_NAME} = $name;
1002         $ENV{GIT_AUTHOR_EMAIL} = $ENV{GIT_COMMITTER_EMAIL} = $email;
1003         $ENV{GIT_AUTHOR_DATE} = $ENV{GIT_COMMITTER_DATE} = $log_msg->{date};
1004 }
1005
1006 sub apply_mod_line_blob {
1007         my $m = shift;
1008         if ($m->{mode_b} =~ /^120/) {
1009                 blob_to_symlink($m->{sha1_b}, $m->{file_b});
1010         } else {
1011                 blob_to_file($m->{sha1_b}, $m->{file_b});
1012         }
1013 }
1014
1015 sub blob_to_symlink {
1016         my ($blob, $link) = @_;
1017         defined $link or croak "\$link not defined!\n";
1018         croak "Not a sha1: $blob\n" unless $blob =~ /^$sha1$/o;
1019         if (-l $link || -f _) {
1020                 unlink $link or croak $!;
1021         }
1022
1023         my $dest = `git-cat-file blob $blob`; # no newline, so no chomp
1024         symlink $dest, $link or croak $!;
1025 }
1026
1027 sub blob_to_file {
1028         my ($blob, $file) = @_;
1029         defined $file or croak "\$file not defined!\n";
1030         croak "Not a sha1: $blob\n" unless $blob =~ /^$sha1$/o;
1031         if (-l $file || -f _) {
1032                 unlink $file or croak $!;
1033         }
1034
1035         open my $blob_fh, '>', $file or croak "$!: $file\n";
1036         my $pid = fork;
1037         defined $pid or croak $!;
1038
1039         if ($pid == 0) {
1040                 open STDOUT, '>&', $blob_fh or croak $!;
1041                 exec('git-cat-file','blob',$blob);
1042         }
1043         waitpid $pid, 0;
1044         croak $? if $?;
1045
1046         close $blob_fh or croak $!;
1047 }
1048
1049 sub safe_qx {
1050         my $pid = open my $child, '-|';
1051         defined $pid or croak $!;
1052         if ($pid == 0) {
1053                 exec(@_) or croak $?;
1054         }
1055         my @ret = (<$child>);
1056         close $child or croak $?;
1057         die $? if $?; # just in case close didn't error out
1058         return wantarray ? @ret : join('',@ret);
1059 }
1060
1061 sub svn_compat_check {
1062         my @co_help = safe_qx(qw(svn co -h));
1063         unless (grep /ignore-externals/,@co_help) {
1064                 print STDERR "W: Installed svn version does not support ",
1065                                 "--ignore-externals\n";
1066                 $_no_ignore_ext = 1;
1067         }
1068         if (grep /usage: checkout URL\[\@REV\]/,@co_help) {
1069                 $_svn_co_url_revs = 1;
1070         }
1071
1072         # I really, really hope nobody hits this...
1073         unless (grep /stop-on-copy/, (safe_qx(qw(svn log -h)))) {
1074                 print STDERR <<'';
1075 W: The installed svn version does not support the --stop-on-copy flag in
1076    the log command.
1077    Lets hope the directory you're tracking is not a branch or tag
1078    and was never moved within the repository...
1079
1080                 $_no_stop_copy = 1;
1081         }
1082 }
1083
1084 # *sigh*, new versions of svn won't honor -r<rev> without URL@<rev>,
1085 # (and they won't honor URL@<rev> without -r<rev>, too!)
1086 sub svn_cmd_checkout {
1087         my ($url, $rev, $dir) = @_;
1088         my @cmd = ('svn','co', "-r$rev");
1089         push @cmd, '--ignore-externals' unless $_no_ignore_ext;
1090         $url .= "\@$rev" if $_svn_co_url_revs;
1091         sys(@cmd, $url, $dir);
1092 }
1093
1094 sub check_upgrade_needed {
1095         my $old = eval {
1096                 my $pid = open my $child, '-|';
1097                 defined $pid or croak $!;
1098                 if ($pid == 0) {
1099                         close STDERR;
1100                         exec('git-rev-parse',"$GIT_SVN-HEAD") or croak $?;
1101                 }
1102                 my @ret = (<$child>);
1103                 close $child or croak $?;
1104                 die $? if $?; # just in case close didn't error out
1105                 return wantarray ? @ret : join('',@ret);
1106         };
1107         return unless $old;
1108         my $head = eval { safe_qx('git-rev-parse',"refs/remotes/$GIT_SVN") };
1109         if ($@ || !$head) {
1110                 print STDERR "Please run: $0 rebuild --upgrade\n";
1111                 exit 1;
1112         }
1113 }
1114
1115 # fills %tree_map with a reverse mapping of trees to commits.  Useful
1116 # for finding parents to commit on.
1117 sub map_tree_joins {
1118         foreach my $br (@_branch_from) {
1119                 my $pid = open my $pipe, '-|';
1120                 defined $pid or croak $!;
1121                 if ($pid == 0) {
1122                         exec(qw(git-rev-list --pretty=raw), $br) or croak $?;
1123                 }
1124                 while (<$pipe>) {
1125                         if (/^commit ($sha1)$/o) {
1126                                 my $commit = $1;
1127                                 my ($tree) = (<$pipe> =~ /^tree ($sha1)$/o);
1128                                 unless (defined $tree) {
1129                                         die "Failed to parse commit $commit\n";
1130                                 }
1131                                 push @{$tree_map{$tree}}, $commit;
1132                         }
1133                 }
1134                 close $pipe or croak $?;
1135         }
1136 }
1137
1138 # '<svn username> = real-name <email address>' mapping based on git-svnimport:
1139 sub load_authors {
1140         open my $authors, '<', $_authors or die "Can't open $_authors $!\n";
1141         while (<$authors>) {
1142                 chomp;
1143                 next unless /^(\S+?)\s*=\s*(.+?)\s*<(.+)>\s*$/;
1144                 my ($user, $name, $email) = ($1, $2, $3);
1145                 $users{$user} = [$name, $email];
1146         }
1147         close $authors or croak $!;
1148 }
1149
1150 __END__
1151
1152 Data structures:
1153
1154 $svn_log hashref (as returned by svn_log_raw)
1155 {
1156         fh => file handle of the log file,
1157         state => state of the log file parser (sep/msg/rev/msg_start...)
1158 }
1159
1160 $log_msg hashref as returned by next_log_entry($svn_log)
1161 {
1162         msg => 'whitespace-formatted log entry
1163 ',                                              # trailing newline is preserved
1164         revision => '8',                        # integer
1165         date => '2004-02-24T17:01:44.108345Z',  # commit date
1166         author => 'committer name'
1167 };
1168
1169
1170 @mods = array of diff-index line hashes, each element represents one line
1171         of diff-index output
1172
1173 diff-index line ($m hash)
1174 {
1175         mode_a => first column of diff-index output, no leading ':',
1176         mode_b => second column of diff-index output,
1177         sha1_b => sha1sum of the final blob,
1178         chg => change type [MCRADT],
1179         file_a => original file name of a file (iff chg is 'C' or 'R')
1180         file_b => new/current file name of a file (any chg)
1181 }
1182 ;