2 package IkiWiki::Plugin::git;
8 use URI::Escape q{uri_escape_utf8};
9 use open qw{:utf8 :std};
11 my $sha1_pattern = qr/[0-9a-fA-F]{40}/; # pattern to validate Git sha1sums
12 my $dummy_commit_msg = 'dummy commit'; # message to skip in recent changes
15 hook(type => "checkconfig", id => "git", call => \&checkconfig);
16 hook(type => "getsetup", id => "git", call => \&getsetup);
17 hook(type => "genwrapper", id => "git", call => \&genwrapper);
18 hook(type => "rcs", id => "rcs_update", call => \&rcs_update);
19 hook(type => "rcs", id => "rcs_prepedit", call => \&rcs_prepedit);
20 hook(type => "rcs", id => "rcs_commit", call => \&rcs_commit);
21 hook(type => "rcs", id => "rcs_commit_staged", call => \&rcs_commit_staged);
22 hook(type => "rcs", id => "rcs_add", call => \&rcs_add);
23 hook(type => "rcs", id => "rcs_remove", call => \&rcs_remove);
24 hook(type => "rcs", id => "rcs_rename", call => \&rcs_rename);
25 hook(type => "rcs", id => "rcs_recentchanges", call => \&rcs_recentchanges);
26 hook(type => "rcs", id => "rcs_diff", call => \&rcs_diff);
27 hook(type => "rcs", id => "rcs_getctime", call => \&rcs_getctime);
28 hook(type => "rcs", id => "rcs_getmtime", call => \&rcs_getmtime);
29 hook(type => "rcs", id => "rcs_receive", call => \&rcs_receive);
30 hook(type => "rcs", id => "rcs_preprevert", call => \&rcs_preprevert);
31 hook(type => "rcs", id => "rcs_revert", call => \&rcs_revert);
32 hook(type => "rcs", id => "rcs_find_changes", call => \&rcs_find_changes);
33 hook(type => "rcs", id => "rcs_get_current_rev", call => \&rcs_get_current_rev);
37 if (! defined $config{gitorigin_branch}) {
38 $config{gitorigin_branch}="origin";
40 if (! defined $config{gitmaster_branch}) {
41 $config{gitmaster_branch}="master";
43 if (defined $config{git_wrapper} &&
44 length $config{git_wrapper}) {
45 push @{$config{wrappers}}, {
46 wrapper => $config{git_wrapper},
47 wrappermode => (defined $config{git_wrappermode} ? $config{git_wrappermode} : "06755"),
48 wrapper_background_command => $config{git_wrapper_background_command},
52 if (defined $config{git_test_receive_wrapper} &&
53 length $config{git_test_receive_wrapper} &&
54 defined $config{untrusted_committers} &&
55 @{$config{untrusted_committers}}) {
56 push @{$config{wrappers}}, {
58 wrapper => $config{git_test_receive_wrapper},
59 wrappermode => (defined $config{git_wrappermode} ? $config{git_wrappermode} : "06755"),
63 # Avoid notes, parser does not handle and they only slow things down.
64 $ENV{GIT_NOTES_REF}="";
66 # Run receive test only if being called by the wrapper, and not
67 # when generating same.
68 if ($config{test_receive} && ! exists $config{wrapper}) {
69 require IkiWiki::Receive;
70 IkiWiki::Receive::test();
77 safe => 0, # rcs plugin
83 example => "/git/wiki.git/hooks/post-update",
84 description => "git hook to generate",
88 git_wrapper_background_command => {
90 example => "git push github",
91 description => "shell command for git_wrapper to run, in the background",
98 description => "mode for git_wrapper (can safely be made suid)",
102 git_test_receive_wrapper => {
104 example => "/git/wiki.git/hooks/pre-receive",
105 description => "git pre-receive hook to generate",
109 untrusted_committers => {
112 description => "unix users whose commits should be checked by the pre-receive hook",
118 example => "http://git.example.com/gitweb.cgi?p=wiki.git;a=history;f=[[file]];hb=HEAD",
119 description => "gitweb url to show file history ([[file]] substituted)",
125 example => "http://git.example.com/gitweb.cgi?p=wiki.git;a=blobdiff;f=[[file]];h=[[sha1_to]];hp=[[sha1_from]];hb=[[sha1_commit]];hpb=[[sha1_parent]]",
126 description => "gitweb url to show a diff ([[file]], [[sha1_to]], [[sha1_from]], [[sha1_commit]], and [[sha1_parent]] substituted)",
130 gitorigin_branch => {
133 description => "where to pull and push changes (set to empty string to disable)",
134 safe => 0, # paranoia
137 gitmaster_branch => {
140 description => "branch that the wiki is stored in",
141 safe => 0, # paranoia
147 if ($config{test_receive}) {
148 require IkiWiki::Receive;
149 return IkiWiki::Receive::genwrapper();
159 sub in_git_dir ($$) {
168 # Start a child process safely without resorting to /bin/sh.
169 # Returns command output (in list content) or success state
170 # (in scalar context), or runs the specified data handler.
172 my ($error_handler, $data_handler, @cmdline) = @_;
174 my $pid = open my $OUT, "-|";
176 error("Cannot fork: $!") if !defined $pid;
180 # Git commands want to be in wc.
181 if (! defined $git_dir) {
182 chdir $config{srcdir}
183 or error("cannot chdir to $config{srcdir}: $!");
187 or error("cannot chdir to $git_dir: $!");
189 exec @cmdline or error("Cannot exec '@cmdline': $!");
193 # git output is probably utf-8 encoded, but may contain
194 # other encodings or invalidly encoded stuff. So do not rely
195 # on the normal utf-8 IO layer, decode it by hand.
200 $_=decode_utf8($_, 0);
204 if (! defined $data_handler) {
208 last unless $data_handler->($_);
214 $error_handler->("'@cmdline' failed: $!") if $? && $error_handler;
216 return wantarray ? @lines : ($? == 0);
218 # Convenient wrappers.
219 sub run_or_die ($@) { safe_git(\&error, undef, @_) }
220 sub run_or_cry ($@) { safe_git(sub { warn @_ }, undef, @_) }
221 sub run_or_non ($@) { safe_git(undef, undef, @_) }
223 my $ensured_committer;
224 sub ensure_committer {
225 return if $ensured_committer;
227 my $name = join('', run_or_non("git", "config", "user.name"));
228 my $email = join('', run_or_non("git", "config", "user.email"));
230 if (! length $name) {
231 run_or_die("git", "config", "user.name", "IkiWiki");
234 if (! length $email) {
235 run_or_die("git", "config", "user.email", "ikiwiki.info");
238 $ensured_committer = 1;
241 sub merge_past ($$$) {
242 # Unlike with Subversion, Git cannot make a 'svn merge -rN:M file'.
243 # Git merge commands work with the committed changes, except in the
244 # implicit case of '-m' of git checkout(1). So we should invent a
245 # kludge here. In principle, we need to create a throw-away branch
246 # in preparing for the merge itself. Since branches are cheap (and
247 # branching is fast), this shouldn't cost high.
249 # The main problem is the presence of _uncommitted_ local changes. One
250 # possible approach to get rid of this situation could be that we first
251 # make a temporary commit in the master branch and later restore the
252 # initial state (this is possible since Git has the ability to undo a
253 # commit, i.e. 'git reset --soft HEAD^'). The method can be summarized
256 # - create a diff of HEAD:current-sha1
258 # - create a dummy branch and switch to it
259 # - rewind to past (reset --hard to the current-sha1)
260 # - apply the diff and commit
261 # - switch to master and do the merge with the dummy branch
262 # - make a soft reset (undo the last commit of master)
264 # The above method has some drawbacks: (1) it needs a redundant commit
265 # just to get rid of local changes, (2) somewhat slow because of the
266 # required system forks. Until someone points a more straight method
267 # (which I would be grateful) I have implemented an alternative method.
268 # In this approach, we hide all the modified files from Git by renaming
269 # them (using the 'rename' builtin) and later restore those files in
270 # the throw-away branch (that is, we put the files themselves instead
271 # of applying a patch).
273 my ($sha1, $file, $message) = @_;
275 my @undo; # undo stack for cleanup in case of an error
276 my $conflict; # file content with conflict markers
281 # Hide local changes from Git by renaming the modified file.
282 # Relative paths must be converted to absolute for renaming.
283 my ($target, $hidden) = (
284 "$config{srcdir}/${file}", "$config{srcdir}/${file}.${sha1}"
286 rename($target, $hidden)
287 or error("rename '$target' to '$hidden' failed: $!");
288 # Ensure to restore the renamed file on error.
290 return if ! -e "$hidden"; # already renamed
291 rename($hidden, $target)
292 or warn "rename '$hidden' to '$target' failed: $!";
295 my $branch = "throw_away_${sha1}"; # supposed to be unique
297 # Create a throw-away branch and rewind backward.
298 push @undo, sub { run_or_cry('git', 'branch', '-D', $branch) };
299 run_or_die('git', 'branch', $branch, $sha1);
301 # Switch to throw-away branch for the merge operation.
303 if (!run_or_cry('git', 'checkout', $config{gitmaster_branch})) {
304 run_or_cry('git', 'checkout','-f',$config{gitmaster_branch});
307 run_or_die('git', 'checkout', $branch);
309 # Put the modified file in _this_ branch.
310 rename($hidden, $target)
311 or error("rename '$hidden' to '$target' failed: $!");
313 # _Silently_ commit all modifications in the current branch.
314 run_or_non('git', 'commit', '-m', $message, '-a');
315 # ... and re-switch to master.
316 run_or_die('git', 'checkout', $config{gitmaster_branch});
318 # Attempt to merge without complaining.
319 if (!run_or_non('git', 'pull', '--no-commit', '.', $branch)) {
320 $conflict = readfile($target);
321 run_or_die('git', 'reset', '--hard');
326 # Process undo stack (in reverse order). By policy cleanup
327 # actions should normally print a warning on failure.
328 while (my $handle = pop @undo) {
332 error("Git merge failed!\n$failure\n") if $failure;
337 sub decode_git_file ($) {
340 # git does not output utf-8 filenames, but instead
341 # double-quotes them with the utf-8 characters
342 # escaped as \nnn\nnn.
343 if ($file =~ m/^"(.*)"$/) {
344 ($file=$1) =~ s/\\([0-7]{1,3})/chr(oct($1))/eg;
347 # strip prefix if in a subdir
348 if (! defined $prefix) {
349 ($prefix) = run_or_die('git', 'rev-parse', '--show-prefix');
350 if (! defined $prefix) {
354 $file =~ s/^\Q$prefix\E//;
356 return decode("utf8", $file);
359 sub parse_diff_tree ($) {
360 # Parse the raw diff tree chunk and return the info hash.
361 # See git-diff-tree(1) for the syntax.
365 return if ! @{ $dt_ref } ||
366 !defined $dt_ref->[0] || !length $dt_ref->[0];
370 while (my $line = shift @{ $dt_ref }) {
371 return if $line !~ m/^(.+) ($sha1_pattern)/;
378 # Identification lines for the commit.
379 while (my $line = shift @{ $dt_ref }) {
380 # Regexps are semi-stolen from gitweb.cgi.
381 if ($line =~ m/^tree ([0-9a-fA-F]{40})$/) {
384 elsif ($line =~ m/^parent ([0-9a-fA-F]{40})$/) {
385 # XXX: collecting in reverse order
386 push @{ $ci{'parents'} }, $1;
388 elsif ($line =~ m/^(author|committer) (.*) ([0-9]+) (.*)$/) {
389 my ($who, $name, $epoch, $tz) =
393 $ci{ "${who}_epoch" } = $epoch;
394 $ci{ "${who}_tz" } = $tz;
396 if ($name =~ m/^([^<]+)\s+<([^@>]+)/) {
397 $ci{"${who}_name"} = $1;
398 $ci{"${who}_username"} = $2;
400 elsif ($name =~ m/^([^<]+)\s+<>$/) {
401 $ci{"${who}_username"} = $1;
404 $ci{"${who}_username"} = $name;
407 elsif ($line =~ m/^$/) {
408 # Trailing empty line signals next section.
413 debug("No 'tree' seen in diff-tree output") if !defined $ci{'tree'};
415 if (defined $ci{'parents'}) {
416 $ci{'parent'} = @{ $ci{'parents'} }[0];
419 $ci{'parent'} = 0 x 40;
422 # Commit message (optional).
423 while ($dt_ref->[0] =~ /^ /) {
424 my $line = shift @{ $dt_ref };
426 push @{ $ci{'comment'} }, $line;
428 shift @{ $dt_ref } if $dt_ref->[0] =~ /^$/;
431 while (my $line = shift @{ $dt_ref }) {
433 (:+) # number of parents
434 ([^\t]+)\t # modes, sha1, status
437 my $num_parents = length $1;
438 my @tmp = split(" ", $2);
439 my ($file, $file_to) = split("\t", $3);
440 my @mode_from = splice(@tmp, 0, $num_parents);
441 my $mode_to = shift(@tmp);
442 my @sha1_from = splice(@tmp, 0, $num_parents);
443 my $sha1_to = shift(@tmp);
444 my $status = shift(@tmp);
447 push @{ $ci{'details'} }, {
448 'file' => decode_git_file($file),
449 'sha1_from' => $sha1_from[0],
450 'sha1_to' => $sha1_to,
451 'mode_from' => $mode_from[0],
452 'mode_to' => $mode_to,
464 sub git_commit_info ($;$) {
465 # Return an array of commit info hashes of num commits
466 # starting from the given sha1sum.
467 my ($sha1, $num) = @_;
470 push @opts, "--max-count=$num" if defined $num;
472 my @raw_lines = run_or_die('git', 'log', @opts,
473 '--pretty=raw', '--raw', '--abbrev=40', '--always', '-c',
474 '-r', $sha1, '--', '.');
477 while (my $parsed = parse_diff_tree(\@raw_lines)) {
481 warn "Cannot parse commit info for '$sha1' commit" if !@ci;
483 return wantarray ? @ci : $ci[0];
486 sub rcs_find_changes ($) {
489 # Note that git log will sometimes show files being added that
490 # don't exist. Particularly, git merge -s ours can result in a
491 # merge commit where some files were not really added.
492 # This is why the code below verifies that the files really
494 my @raw_lines = run_or_die('git', 'log',
495 '--pretty=raw', '--raw', '--abbrev=40', '--always', '-c',
496 '--no-renames', , '--reverse',
497 '-r', "$oldrev..HEAD", '--', '.');
499 # Due to --reverse, we see changes in chronological order.
502 my $nullsha = 0 x 40;
504 while (my $ci = parse_diff_tree(\@raw_lines)) {
506 foreach my $i (@{$ci->{details}}) {
508 if ($i->{sha1_to} eq $nullsha) {
509 if (! -e "$config{srcdir}/$file") {
510 delete $changed{$file};
515 if (-e "$config{srcdir}/$file") {
516 delete $deleted{$file};
523 return (\%changed, \%deleted, $newrev);
526 sub git_sha1_file ($) {
528 git_sha1("--", $file);
532 # Ignore error since a non-existing file might be given.
533 my ($sha1) = run_or_non('git', 'rev-list', '--max-count=1', 'HEAD',
536 ($sha1) = $sha1 =~ m/($sha1_pattern)/; # sha1 is untainted now
538 return defined $sha1 ? $sha1 : '';
541 sub rcs_get_current_rev () {
546 # Update working directory.
550 if (length $config{gitorigin_branch}) {
551 run_or_cry('git', 'pull', '--prune', $config{gitorigin_branch});
555 sub rcs_prepedit ($) {
556 # Return the commit sha1sum of the file when editing begins.
557 # This will be later used in rcs_commit if a merge is required.
560 return git_sha1_file($file);
564 # Try to commit the page; returns undef on _success_ and
565 # a version of the page with the rcs's conflict markers on
569 # Check to see if the page has been changed by someone else since
570 # rcs_prepedit was called.
571 my $cur = git_sha1_file($params{file});
572 my ($prev) = $params{token} =~ /^($sha1_pattern)$/; # untaint
574 if (defined $cur && defined $prev && $cur ne $prev) {
575 my $conflict = merge_past($prev, $params{file}, $dummy_commit_msg);
576 return $conflict if defined $conflict;
579 return rcs_commit_helper(@_);
582 sub rcs_commit_staged (@) {
583 # Commits all staged changes. Changes can be staged using rcs_add,
584 # rcs_remove, and rcs_rename.
585 return rcs_commit_helper(@_);
588 sub rcs_commit_helper (@) {
595 if (defined $params{session}) {
596 # Set the commit author and email based on web session info.
598 if (defined $params{session}->param("name")) {
599 $u=$params{session}->param("name");
601 elsif (defined $params{session}->remote_addr()) {
602 $u=$params{session}->remote_addr();
606 $ENV{GIT_AUTHOR_NAME}=$u;
608 if (defined $params{session}->param("nickname")) {
609 $u=encode_utf8($params{session}->param("nickname"));
611 $u=~s/[^-_0-9[:alnum:]]+//g;
614 $ENV{GIT_AUTHOR_EMAIL}="$u\@web";
618 $params{message} = IkiWiki::possibly_foolish_untaint($params{message});
620 if ($params{message} !~ /\S/) {
621 # Force git to allow empty commit messages.
622 # (If this version of git supports it.)
623 my ($version)=`git --version` =~ /git version (.*)/;
624 if ($version ge "1.7.8") {
625 push @opts, "--allow-empty-message", "--no-edit";
627 if ($version ge "1.7.2") {
628 push @opts, "--allow-empty-message";
630 elsif ($version ge "1.5.4") {
631 push @opts, '--cleanup=verbatim';
634 $params{message}.=".";
637 if (exists $params{file}) {
638 push @opts, '--', $params{file};
640 # git commit returns non-zero if nothing really changed.
641 # So we should ignore its exit status (hence run_or_non).
642 if (run_or_non('git', 'commit', '-m', $params{message}, '-q', @opts)) {
643 if (length $config{gitorigin_branch}) {
644 run_or_cry('git', 'push', $config{gitorigin_branch}, $config{gitmaster_branch});
649 return undef; # success
653 # Add file to archive.
659 run_or_cry('git', 'add', $file);
663 # Remove file from archive.
669 run_or_cry('git', 'rm', '-f', $file);
672 sub rcs_rename ($$) {
673 my ($src, $dest) = @_;
677 run_or_cry('git', 'mv', '-f', $src, $dest);
680 sub rcs_recentchanges ($) {
681 # List of recent changes.
685 eval q{use Date::Parse};
689 foreach my $ci (git_commit_info('HEAD', $num || 1)) {
690 # Skip redundant commits.
691 next if ($ci->{'comment'} && @{$ci->{'comment'}}[0] eq $dummy_commit_msg);
693 my ($sha1, $when) = (
695 $ci->{'author_epoch'}
699 foreach my $detail (@{ $ci->{'details'} }) {
700 my $file = $detail->{'file'};
701 my $efile = join('/',
702 map { uri_escape_utf8($_) } split('/', $file)
705 my $diffurl = defined $config{'diffurl'} ? $config{'diffurl'} : "";
706 $diffurl =~ s/\[\[file\]\]/$efile/go;
707 $diffurl =~ s/\[\[sha1_parent\]\]/$ci->{'parent'}/go;
708 $diffurl =~ s/\[\[sha1_from\]\]/$detail->{'sha1_from'}/go;
709 $diffurl =~ s/\[\[sha1_to\]\]/$detail->{'sha1_to'}/go;
710 $diffurl =~ s/\[\[sha1_commit\]\]/$sha1/go;
713 page => pagename($file),
720 foreach my $line (@{$ci->{'comment'}}) {
721 $pastblank=1 if $line eq '';
722 next if $pastblank && $line=~m/^ *(signed[ \-]off[ \-]by[ :]|acked[ \-]by[ :]|cc[ :])/i;
723 push @messages, { line => $line };
726 my $user=$ci->{'author_username'};
727 my $web_commit = ($ci->{'author'} =~ /\@web>/);
730 # Set nickname only if a non-url author_username is available,
731 # and author_name is an url.
732 if ($user !~ /:\/\// && defined $ci->{'author_name'} &&
733 $ci->{'author_name'} =~ /:\/\//) {
735 $user=$ci->{'author_name'};
738 # compatability code for old web commit messages
740 defined $messages[0] &&
741 $messages[0]->{line} =~ m/$config{web_commit_regexp}/) {
742 $user = defined $2 ? "$2" : "$3";
743 $messages[0]->{line} = $4;
750 nickname => $nickname,
751 committype => $web_commit ? "web" : "git",
753 message => [@messages],
757 last if @rets >= $num;
766 my ($sha1) = $rev =~ /^($sha1_pattern)$/; # untaint
770 return if defined $maxlines && @lines == $maxlines;
771 push @lines, $line."\n"
772 if (@lines || $line=~/^diff --git/);
775 safe_git(undef, $addlines, "git", "show", $sha1);
780 return join("", @lines);
789 my $id=shift; # 0 = mtime ; 1 = ctime
791 if (! keys %time_cache) {
793 foreach my $line (run_or_die('git', 'log',
794 '--pretty=format:%at',
795 '--name-only', '--relative')) {
796 if (! defined $date && $line =~ /^(\d+)$/) {
799 elsif (! length $line) {
803 my $f=decode_git_file($line);
805 if (! $time_cache{$f}) {
806 $time_cache{$f}[0]=$date; # mtime
808 $time_cache{$f}[1]=$date; # ctime
813 return exists $time_cache{$file} ? $time_cache{$file}[$id] : 0;
818 sub rcs_getctime ($) {
821 return findtimes($file, 1);
824 sub rcs_getmtime ($) {
827 return findtimes($file, 0);
833 # The wiki may not be the only thing in the git repo.
834 # Determine if it is in a subdirectory by examining the srcdir,
835 # and its parents, looking for the .git directory.
837 return @$ret if defined $ret;
840 my $dir=$config{srcdir};
841 while (! -d "$dir/.git") {
842 $subdir=IkiWiki::basename($dir)."/".$subdir;
843 $dir=IkiWiki::dirname($dir);
845 error("cannot determine root of git repo");
849 $ret=[$subdir, $dir];
855 sub git_parse_changes {
856 my $reverted = shift;
859 my ($subdir, $rootdir) = git_find_root();
861 foreach my $ci (@changes) {
862 foreach my $detail (@{ $ci->{'details'} }) {
863 my $file = $detail->{'file'};
865 # check that all changed files are in the subdir
866 if (length $subdir &&
867 ! ($file =~ s/^\Q$subdir\E//)) {
868 error sprintf(gettext("you are not allowed to change %s"), $file);
871 my ($action, $mode, $path);
872 if ($detail->{'status'} =~ /^[M]+\d*$/) {
874 $mode=$detail->{'mode_to'};
876 elsif ($detail->{'status'} =~ /^[AM]+\d*$/) {
877 $action= $reverted ? "remove" : "add";
878 $mode=$detail->{'mode_to'};
880 elsif ($detail->{'status'} =~ /^[DAM]+\d*/) {
881 $action= $reverted ? "add" : "remove";
882 $mode=$detail->{'mode_from'};
885 error "unknown status ".$detail->{'status'};
888 # test that the file mode is ok
889 if ($mode !~ /^100[64][64][64]$/) {
890 error sprintf(gettext("you cannot act on a file with mode %s"), $mode);
892 if ($action eq "change") {
893 if ($detail->{'mode_from'} ne $detail->{'mode_to'}) {
894 error gettext("you are not allowed to change file modes");
898 # extract attachment to temp file
899 if (($action eq 'add' || $action eq 'change') &&
901 eval q{use File::Temp};
904 ($fh, $path)=File::Temp::tempfile(undef, UNLINK => 1);
905 my $cmd = "cd $git_dir && ".
906 "git show $detail->{sha1_to} > '$path'";
907 if (system($cmd) != 0) {
908 error("failed writing temp file '$path'.");
927 my ($oldrev, $newrev, $refname) = split(' ', $_, 3);
929 # only allow changes to gitmaster_branch
930 if ($refname !~ /^refs\/heads\/\Q$config{gitmaster_branch}\E$/) {
931 error sprintf(gettext("you are not allowed to change %s"), $refname);
934 # Avoid chdir when running git here, because the changes
935 # are in the master git repo, not the srcdir repo.
936 # (Also, if a subdir is involved, we don't want to chdir to
937 # it and only see changes in it.)
938 # The pre-receive hook already puts us in the right place.
939 in_git_dir(".", sub {
940 push @rets, git_parse_changes(0, git_commit_info($oldrev."..".$newrev));
944 return reverse @rets;
947 sub rcs_preprevert ($) {
949 my ($sha1) = $rev =~ /^($sha1_pattern)$/; # untaint
951 # Examine changes from root of git repo, not from any subdir,
952 # in order to see all changes.
953 my ($subdir, $rootdir) = git_find_root();
954 in_git_dir($rootdir, sub {
955 my @commits=git_commit_info($sha1, 1);
958 error "unknown commit"; # just in case
961 # git revert will fail on merge commits. Add a nice message.
962 if (exists $commits[0]->{parents} &&
963 @{$commits[0]->{parents}} > 1) {
964 error gettext("you are not allowed to revert a merge");
967 git_parse_changes(1, @commits);
972 # Try to revert the given rev; returns undef on _success_.
974 my ($sha1) = $rev =~ /^($sha1_pattern)$/; # untaint
978 if (run_or_non('git', 'revert', '--no-commit', $sha1)) {
982 run_or_die('git', 'reset', '--hard');
983 return sprintf(gettext("Failed to revert commit %s"), $sha1);