]> sipb.mit.edu Git - ikiwiki.git/blobdiff - IkiWiki/Plugin/git.pm
First cut at the revert plugin.
[ikiwiki.git] / IkiWiki / Plugin / git.pm
index 5e302729ea1c26c80c93d4974e94e8a57e444012..a68bd0b0e142e81be5fa78739c6490a2c7b8ae2c 100644 (file)
@@ -9,10 +9,12 @@ use open qw{:utf8 :std};
 
 my $sha1_pattern     = qr/[0-9a-fA-F]{40}/; # pattern to validate Git sha1sums
 my $dummy_commit_msg = 'dummy commit';      # message to skip in recent changes
+my $no_chdir=0;
 
-sub import { #{{{
+sub import {
        hook(type => "checkconfig", id => "git", call => \&checkconfig);
        hook(type => "getsetup", id => "git", call => \&getsetup);
+       hook(type => "genwrapper", id => "git", call => \&genwrapper);
        hook(type => "rcs", id => "rcs_update", call => \&rcs_update);
        hook(type => "rcs", id => "rcs_prepedit", call => \&rcs_prepedit);
        hook(type => "rcs", id => "rcs_commit", call => \&rcs_commit);
@@ -23,32 +25,73 @@ sub import { #{{{
        hook(type => "rcs", id => "rcs_recentchanges", call => \&rcs_recentchanges);
        hook(type => "rcs", id => "rcs_diff", call => \&rcs_diff);
        hook(type => "rcs", id => "rcs_getctime", call => \&rcs_getctime);
-} #}}}
+       hook(type => "rcs", id => "rcs_getmtime", call => \&rcs_getmtime);
+       hook(type => "rcs", id => "rcs_receive", call => \&rcs_receive);
+       hook(type => "rcs", id => "rcs_preprevert", call => \&rcs_preprevert);
+       hook(type => "rcs", id => "rcs_revert", call => \&rcs_revert);
+       hook(type => "rcs", id => "rcs_showpatch", call => \&rcs_showpatch);
+       hook(type => "rcs", id => "rcs_revert", call => \&rcs_revert);
+}
 
-sub checkconfig () { #{{{
+sub checkconfig () {
        if (! defined $config{gitorigin_branch}) {
                $config{gitorigin_branch}="origin";
        }
        if (! defined $config{gitmaster_branch}) {
                $config{gitmaster_branch}="master";
        }
-       if (defined $config{git_wrapper} && length $config{git_wrapper}) {
+       if (defined $config{git_wrapper} &&
+           length $config{git_wrapper}) {
                push @{$config{wrappers}}, {
                        wrapper => $config{git_wrapper},
                        wrappermode => (defined $config{git_wrappermode} ? $config{git_wrappermode} : "06755"),
+                       wrapper_background_command => $config{git_wrapper_background_command},
+               };
+       }
+
+       if (defined $config{git_test_receive_wrapper} &&
+           length $config{git_test_receive_wrapper} &&
+           defined $config{untrusted_committers} &&
+           @{$config{untrusted_committers}}) {
+               push @{$config{wrappers}}, {
+                       test_receive => 1,
+                       wrapper => $config{git_test_receive_wrapper},
+                       wrappermode => (defined $config{git_wrappermode} ? $config{git_wrappermode} : "06755"),
                };
        }
-} #}}}
 
-sub getsetup () { #{{{
+       # Avoid notes, parser does not handle and they only slow things down.
+       $ENV{GIT_NOTES_REF}="";
+       
+       # Run receive test only if being called by the wrapper, and not
+       # when generating same.
+       if ($config{test_receive} && ! exists $config{wrapper}) {
+               require IkiWiki::Receive;
+               IkiWiki::Receive::test();
+       }
+}
+
+sub getsetup () {
        return
+               plugin => {
+                       safe => 0, # rcs plugin
+                       rebuild => undef,
+                       section => "rcs",
+               },
                git_wrapper => {
                        type => "string",
                        example => "/git/wiki.git/hooks/post-update",
-                       description => "git post-update executable to generate",
+                       description => "git hook to generate",
                        safe => 0, # file
                        rebuild => 0,
                },
+               git_wrapper_background_command => {
+                       type => "string",
+                       example => "git push github",
+                       description => "shell command for git_wrapper to run, in the background",
+                       safe => 0, # command
+                       rebuild => 0,
+               },
                git_wrappermode => {
                        type => "string",
                        example => '06755',
@@ -56,17 +99,31 @@ sub getsetup () { #{{{
                        safe => 0,
                        rebuild => 0,
                },
+               git_test_receive_wrapper => {
+                       type => "string",
+                       example => "/git/wiki.git/hooks/pre-receive",
+                       description => "git pre-receive hook to generate",
+                       safe => 0, # file
+                       rebuild => 0,
+               },
+               untrusted_committers => {
+                       type => "string",
+                       example => [],
+                       description => "unix users whose commits should be checked by the pre-receive hook",
+                       safe => 0,
+                       rebuild => 0,
+               },
                historyurl => {
                        type => "string",
-                       example => "http://git.example.com/gitweb.cgi?p=wiki.git;a=history;f=[[file]]",
+                       example => "http://git.example.com/gitweb.cgi?p=wiki.git;a=history;f=[[file]];hb=HEAD",
                        description => "gitweb url to show file history ([[file]] substituted)",
                        safe => 1,
                        rebuild => 1,
                },
                diffurl => {
                        type => "string",
-                       example => "http://git.example.com/gitweb.cgi?p=wiki.git;a=blobdiff;h=[[sha1_to]];hp=[[sha1_from]];hb=[[sha1_parent]];f=[[file]]",
-                       description => "gitweb url to show a diff ([[sha1_to]], [[sha1_from]], [[sha1_parent]], and [[file]] substituted)",
+                       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]]",
+                       description => "gitweb url to show a diff ([[file]], [[sha1_to]], [[sha1_from]], [[sha1_commit]], and [[sha1_parent]] substituted)",
                        safe => 1,
                        rebuild => 1,
                },
@@ -84,9 +141,19 @@ sub getsetup () { #{{{
                        safe => 0, # paranoia
                        rebuild => 0,
                },
-} #}}}
+}
 
-sub safe_git (&@) { #{{{
+sub genwrapper {
+       if ($config{test_receive}) {
+               require IkiWiki::Receive;
+               return IkiWiki::Receive::genwrapper();
+       }
+       else {
+               return "";
+       }
+}
+
+sub safe_git (&@) {
        # Start a child process safely without resorting /bin/sh.
        # Return command output or success state (in scalar context).
 
@@ -99,15 +166,25 @@ sub safe_git (&@) { #{{{
        if (!$pid) {
                # In child.
                # Git commands want to be in wc.
-               chdir $config{srcdir}
-                   or error("Cannot chdir to $config{srcdir}: $!");
+               if (! $no_chdir) {
+                       chdir $config{srcdir}
+                           or error("Cannot chdir to $config{srcdir}: $!");
+               }
                exec @cmdline or error("Cannot exec '@cmdline': $!");
        }
        # In parent.
 
+       # git output is probably utf-8 encoded, but may contain
+       # other encodings or invalidly encoded stuff. So do not rely
+       # on the normal utf-8 IO layer, decode it by hand.
+       binmode($OUT);
+
        my @lines;
        while (<$OUT>) {
+               $_=decode_utf8($_, 0);
+
                chomp;
+
                push @lines, $_;
        }
 
@@ -121,9 +198,9 @@ sub safe_git (&@) { #{{{
 sub run_or_die ($@) { safe_git(\&error, @_) }
 sub run_or_cry ($@) { safe_git(sub { warn @_ },  @_) }
 sub run_or_non ($@) { safe_git(undef,            @_) }
-#}}}
 
-sub merge_past ($$$) { #{{{
+
+sub merge_past ($$$) {
        # Unlike with Subversion, Git cannot make a 'svn merge -rN:M file'.
        # Git merge commands work with the committed changes, except in the
        # implicit case of '-m' of git checkout(1).  So we should invent a
@@ -215,13 +292,37 @@ sub merge_past ($$$) { #{{{
        error("Git merge failed!\n$failure\n") if $failure;
 
        return $conflict;
-} #}}}
+}
+
+{
+my $prefix;
+sub decode_git_file ($) {
+       my $file=shift;
+
+       # git does not output utf-8 filenames, but instead
+       # double-quotes them with the utf-8 characters
+       # escaped as \nnn\nnn.
+       if ($file =~ m/^"(.*)"$/) {
+               ($file=$1) =~ s/\\([0-7]{1,3})/chr(oct($1))/eg;
+       }
 
-sub parse_diff_tree ($@) { #{{{
+       # strip prefix if in a subdir
+       if (! defined $prefix) {
+               ($prefix) = run_or_die('git', 'rev-parse', '--show-prefix');
+               if (! defined $prefix) {
+                       $prefix="";
+               }
+       }
+       $file =~ s/^\Q$prefix\E//;
+
+       return decode("utf8", $file);
+}
+}
+
+sub parse_diff_tree ($) {
        # Parse the raw diff tree chunk and return the info hash.
        # See git-diff-tree(1) for the syntax.
-
-       my ($prefix, $dt_ref) = @_;
+       my $dt_ref = shift;
 
        # End of stream?
        return if !defined @{ $dt_ref } ||
@@ -255,8 +356,9 @@ sub parse_diff_tree ($@) { #{{{
                        $ci{ "${who}_epoch" } = $epoch;
                        $ci{ "${who}_tz"    } = $tz;
 
-                       if ($name =~ m/^[^<]+\s+<([^@>]+)/) {
-                               $ci{"${who}_username"} = $1;
+                       if ($name =~ m/^([^<]+)\s+<([^@>]+)/) {
+                               $ci{"${who}_name"} = $1;
+                               $ci{"${who}_username"} = $2;
                        }
                        elsif ($name =~ m/^([^<]+)\s+<>$/) {
                                $ci{"${who}_username"} = $1;
@@ -304,15 +406,14 @@ sub parse_diff_tree ($@) { #{{{
                        my $sha1_to = shift(@tmp);
                        my $status = shift(@tmp);
 
-                       if ($file =~ m/^"(.*)"$/) {
-                               ($file=$1) =~ s/\\([0-7]{1,3})/chr(oct($1))/eg;
-                       }
-                       $file =~ s/^\Q$prefix\E//;
                        if (length $file) {
                                push @{ $ci{'details'} }, {
-                                       'file'      => decode_utf8($file),
+                                       'file'      => decode_git_file($file),
                                        'sha1_from' => $sha1_from[0],
                                        'sha1_to'   => $sha1_to,
+                                       'mode_from' => $mode_from[0],
+                                       'mode_to'   => $mode_to,
+                                       'status'    => $status,
                                };
                        }
                        next;
@@ -321,34 +422,32 @@ sub parse_diff_tree ($@) { #{{{
        }
 
        return \%ci;
-} #}}}
+}
 
-sub git_commit_info ($;$) { #{{{
-       # Return an array of commit info hashes of num commits (default: 1)
+sub git_commit_info ($;$) {
+       # Return an array of commit info hashes of num commits
        # starting from the given sha1sum.
-
        my ($sha1, $num) = @_;
 
-       $num ||= 1;
+       my @opts;
+       push @opts, "--max-count=$num" if defined $num;
 
-       my @raw_lines = run_or_die('git', 'log', "--max-count=$num", 
+       my @raw_lines = run_or_die('git', 'log', @opts,
                '--pretty=raw', '--raw', '--abbrev=40', '--always', '-c',
                '-r', $sha1, '--', '.');
-       my ($prefix) = run_or_die('git', 'rev-parse', '--show-prefix');
 
        my @ci;
-       while (my $parsed = parse_diff_tree(($prefix or ""), \@raw_lines)) {
+       while (my $parsed = parse_diff_tree(\@raw_lines)) {
                push @ci, $parsed;
        }
 
        warn "Cannot parse commit info for '$sha1' commit" if !@ci;
 
        return wantarray ? @ci : $ci[0];
-} #}}}
+}
 
-sub git_sha1 (;$) { #{{{
+sub git_sha1 (;$) {
        # Return head sha1sum (of given file).
-
        my $file = shift || q{--};
 
        # Ignore error since a non-existing file might be given.
@@ -356,66 +455,99 @@ sub git_sha1 (;$) { #{{{
                '--', $file);
        if ($sha1) {
                ($sha1) = $sha1 =~ m/($sha1_pattern)/; # sha1 is untainted now
-       } else { debug("Empty sha1sum for '$file'.") }
+       }
+       else {
+               debug("Empty sha1sum for '$file'.");
+       }
        return defined $sha1 ? $sha1 : q{};
-} #}}}
+}
 
-sub rcs_update () { #{{{
+sub rcs_update () {
        # Update working directory.
 
        if (length $config{gitorigin_branch}) {
-               run_or_cry('git', 'pull', $config{gitorigin_branch});
+               run_or_cry('git', 'pull', '--prune', $config{gitorigin_branch});
        }
-} #}}}
+}
 
-sub rcs_prepedit ($) { #{{{
+sub rcs_prepedit ($) {
        # Return the commit sha1sum of the file when editing begins.
        # This will be later used in rcs_commit if a merge is required.
-
        my ($file) = @_;
 
        return git_sha1($file);
-} #}}}
+}
 
-sub rcs_commit ($$$;$$) { #{{{
+sub rcs_commit (@) {
        # Try to commit the page; returns undef on _success_ and
        # a version of the page with the rcs's conflict markers on
        # failure.
-
-       my ($file, $message, $rcstoken, $user, $ipaddr) = @_;
+       my %params=@_;
 
        # Check to see if the page has been changed by someone else since
        # rcs_prepedit was called.
-       my $cur    = git_sha1($file);
-       my ($prev) = $rcstoken =~ /^($sha1_pattern)$/; # untaint
+       my $cur    = git_sha1($params{file});
+       my ($prev) = $params{token} =~ /^($sha1_pattern)$/; # untaint
 
        if (defined $cur && defined $prev && $cur ne $prev) {
-               my $conflict = merge_past($prev, $file, $dummy_commit_msg);
+               my $conflict = merge_past($prev, $params{file}, $dummy_commit_msg);
                return $conflict if defined $conflict;
        }
 
-       rcs_add($file); 
-       return rcs_commit_staged($message, $user, $ipaddr);
-} #}}}
+       rcs_add($params{file});
+       return rcs_commit_staged(
+               message => $params{message},
+               session => $params{session},
+       );
+}
 
-sub rcs_commit_staged ($$$) {
+sub rcs_commit_staged (@) {
        # Commits all staged changes. Changes can be staged using rcs_add,
        # rcs_remove, and rcs_rename.
-       my ($message, $user, $ipaddr)=@_;
-
-       # Set the commit author and email to the web committer.
+       my %params=@_;
+       
        my %env=%ENV;
-       if (defined $user || defined $ipaddr) {
-               my $u=defined $user ? $user : $ipaddr;
-               $ENV{GIT_AUTHOR_NAME}=$u;
-               $ENV{GIT_AUTHOR_EMAIL}="$u\@web";
+
+       if (defined $params{session}) {
+               # Set the commit author and email based on web session info.
+               my $u;
+               if (defined $params{session}->param("name")) {
+                       $u=$params{session}->param("name");
+               }
+               elsif (defined $params{session}->remote_addr()) {
+                       $u=$params{session}->remote_addr();
+               }
+               if (defined $u) {
+                       $u=encode_utf8($u);
+                       $ENV{GIT_AUTHOR_NAME}=$u;
+               }
+               if (defined $params{session}->param("nickname")) {
+                       $u=encode_utf8($params{session}->param("nickname"));
+                       $u=~s/\s+/_/g;
+                       $u=~s/[^-_0-9[:alnum:]]+//g;
+               }
+               if (defined $u) {
+                       $ENV{GIT_AUTHOR_EMAIL}="$u\@web";
+               }
        }
 
+       $params{message} = IkiWiki::possibly_foolish_untaint($params{message});
+       my @opts;
+       if ($params{message} !~ /\S/) {
+               # Force git to allow empty commit messages.
+               # (If this version of git supports it.)
+               my ($version)=`git --version` =~ /git version (.*)/;
+               if ($version ge "1.5.4") {
+                       push @opts, '--cleanup=verbatim';
+               }
+               else {
+                       $params{message}.=".";
+               }
+       }
+       push @opts, '-q';
        # git commit returns non-zero if file has not been really changed.
        # so we should ignore its exit status (hence run_or_non).
-       $message = IkiWiki::possibly_foolish_untaint($message);
-       if (run_or_non('git', 'commit', '--cleanup=verbatim',
-                      '-q', '-m', $message)) {
+       if (run_or_non('git', 'commit', @opts, '-m', $params{message})) {
                if (length $config{gitorigin_branch}) {
                        run_or_cry('git', 'push', $config{gitorigin_branch});
                }
@@ -425,29 +557,29 @@ sub rcs_commit_staged ($$$) {
        return undef; # success
 }
 
-sub rcs_add ($) { # {{{
+sub rcs_add ($) {
        # Add file to archive.
 
        my ($file) = @_;
 
        run_or_cry('git', 'add', $file);
-} #}}}
+}
 
-sub rcs_remove ($) { # {{{
+sub rcs_remove ($) {
        # Remove file from archive.
 
        my ($file) = @_;
 
        run_or_cry('git', 'rm', '-f', $file);
-} #}}}
+}
 
-sub rcs_rename ($$) { # {{{
+sub rcs_rename ($$) {
        my ($src, $dest) = @_;
 
        run_or_cry('git', 'mv', '-f', $src, $dest);
-} #}}}
+}
 
-sub rcs_recentchanges ($) { #{{{
+sub rcs_recentchanges ($) {
        # List of recent changes.
 
        my ($num) = @_;
@@ -456,7 +588,7 @@ sub rcs_recentchanges ($) { #{{{
        error($@) if $@;
 
        my @rets;
-       foreach my $ci (git_commit_info('HEAD', $num)) {
+       foreach my $ci (git_commit_info('HEAD', $num || 1)) {
                # Skip redundant commits.
                next if ($ci->{'comment'} && @{$ci->{'comment'}}[0] eq $dummy_commit_msg);
 
@@ -474,6 +606,7 @@ sub rcs_recentchanges ($) { #{{{
                        $diffurl =~ s/\[\[sha1_parent\]\]/$ci->{'parent'}/go;
                        $diffurl =~ s/\[\[sha1_from\]\]/$detail->{'sha1_from'}/go;
                        $diffurl =~ s/\[\[sha1_to\]\]/$detail->{'sha1_to'}/go;
+                       $diffurl =~ s/\[\[sha1_commit\]\]/$sha1/go;
 
                        push @pages, {
                                page => pagename($file),
@@ -491,7 +624,16 @@ sub rcs_recentchanges ($) { #{{{
 
                my $user=$ci->{'author_username'};
                my $web_commit = ($ci->{'author'} =~ /\@web>/);
-               
+               my $nickname;
+
+               # Set nickname only if a non-url author_username is available,
+               # and author_name is an url.
+               if ($user !~ /:\/\// && defined $ci->{'author_name'} &&
+                   $ci->{'author_name'} =~ /:\/\//) {
+                       $nickname=$user;
+                       $user=$ci->{'author_name'};
+               }
+
                # compatability code for old web commit messages
                if (! $web_commit &&
                      defined $messages[0] &&
@@ -504,6 +646,7 @@ sub rcs_recentchanges ($) { #{{{
                push @rets, {
                        rev        => $sha1,
                        user       => $user,
+                       nickname   => $nickname,
                        committype => $web_commit ? "web" : "git",
                        when       => $when,
                        message    => [@messages],
@@ -514,9 +657,9 @@ sub rcs_recentchanges ($) { #{{{
        }
 
        return @rets;
-} #}}}
+}
 
-sub rcs_diff ($) { #{{{
+sub rcs_diff ($) {
        my $rev=shift;
        my ($sha1) = $rev =~ /^($sha1_pattern)$/; # untaint
        my @lines;
@@ -531,19 +674,176 @@ sub rcs_diff ($) { #{{{
        else {
                return join("", @lines);
        }
-} #}}}
+}
+
+{
+my %time_cache;
+
+sub findtimes ($$) {
+       my $file=shift;
+       my $id=shift; # 0 = mtime ; 1 = ctime
+
+       if (! keys %time_cache) {
+               my $date;
+               foreach my $line (run_or_die('git', 'log',
+                               '--pretty=format:%ct',
+                               '--name-only', '--relative')) {
+                       if (! defined $date && $line =~ /^(\d+)$/) {
+                               $date=$line;
+                       }
+                       elsif (! length $line) {
+                               $date=undef;
+                       }
+                       else {
+                               my $f=decode_git_file($line);
+
+                               if (! $time_cache{$f}) {
+                                       $time_cache{$f}[0]=$date; # mtime
+                               }
+                               $time_cache{$f}[1]=$date; # ctime
+                       }
+               }
+       }
+
+       return exists $time_cache{$file} ? $time_cache{$file}[$id] : 0;
+}
+
+}
+
+sub rcs_getctime ($) {
+       my $file=shift;
+
+       return findtimes($file, 1);
+}
 
-sub rcs_getctime ($) { #{{{
+sub rcs_getmtime ($) {
        my $file=shift;
-       # Remove srcdir prefix
-       $file =~ s/^\Q$config{srcdir}\E\/?//;
 
-       my $sha1  = git_sha1($file);
-       my $ci    = git_commit_info($sha1);
-       my $ctime = $ci->{'author_epoch'};
-       debug("ctime for '$file': ". localtime($ctime));
+       return findtimes($file, 0);
+}
+
+sub rcs_receive () {
+       # The wiki may not be the only thing in the git repo.
+       # Determine if it is in a subdirectory by examining the srcdir,
+       # and its parents, looking for the .git directory.
+       my $subdir="";
+       my $dir=$config{srcdir};
+       while (! -d "$dir/.git") {
+               $subdir=IkiWiki::basename($dir)."/".$subdir;
+               $dir=IkiWiki::dirname($dir);
+               if (! length $dir) {
+                       error("cannot determine root of git repo");
+               }
+       }
+
+       my @rets;
+       while (<>) {
+               chomp;
+               my ($oldrev, $newrev, $refname) = split(' ', $_, 3);
+               
+               # only allow changes to gitmaster_branch
+               if ($refname !~ /^refs\/heads\/\Q$config{gitmaster_branch}\E$/) {
+                       error sprintf(gettext("you are not allowed to change %s"), $refname);
+               }
+               
+               # Avoid chdir when running git here, because the changes
+               # are in the master git repo, not the srcdir repo.
+               # The pre-recieve hook already puts us in the right place.
+               $no_chdir=1;
+               my @changes=git_commit_info($oldrev."..".$newrev);
+               $no_chdir=0;
+
+               foreach my $ci (@changes) {
+                       foreach my $detail (@{ $ci->{'details'} }) {
+                               my $file = $detail->{'file'};
+
+                               # check that all changed files are in the
+                               # subdir
+                               if (length $subdir &&
+                                   ! ($file =~ s/^\Q$subdir\E//)) {
+                                       error sprintf(gettext("you are not allowed to change %s"), $file);
+                               }
+
+                               my ($action, $mode, $path);
+                               if ($detail->{'status'} =~ /^[M]+\d*$/) {
+                                       $action="change";
+                                       $mode=$detail->{'mode_to'};
+                               }
+                               elsif ($detail->{'status'} =~ /^[AM]+\d*$/) {
+                                       $action="add";
+                                       $mode=$detail->{'mode_to'};
+                               }
+                               elsif ($detail->{'status'} =~ /^[DAM]+\d*/) {
+                                       $action="remove";
+                                       $mode=$detail->{'mode_from'};
+                               }
+                               else {
+                                       error "unknown status ".$detail->{'status'};
+                               }
+                               
+                               # test that the file mode is ok
+                               if ($mode !~ /^100[64][64][64]$/) {
+                                       error sprintf(gettext("you cannot act on a file with mode %s"), $mode);
+                               }
+                               if ($action eq "change") {
+                                       if ($detail->{'mode_from'} ne $detail->{'mode_to'}) {
+                                               error gettext("you are not allowed to change file modes");
+                                       }
+                               }
+                               
+                               # extract attachment to temp file
+                               if (($action eq 'add' || $action eq 'change') &&
+                                    ! pagetype($file)) {
+                                       eval q{use File::Temp};
+                                       die $@ if $@;
+                                       my $fh;
+                                       ($fh, $path)=File::Temp::tempfile("XXXXXXXXXX", UNLINK => 1);
+                                       if (system("git show ".$detail->{sha1_to}." > '$path'") != 0) {
+                                               error("failed writing temp file");
+                                       }
+                               }
+
+                               push @rets, {
+                                       file => $file,
+                                       action => $action,
+                                       path => $path,
+                               };
+                       }
+               }
+       }
+
+       return reverse @rets;
+}
 
-       return $ctime;
-} #}}}
+sub rcs_preprevert ($) {
+    # FIXME implement
+}
+
+sub rcs_revert (@) {
+    # Try to revert the given patch; returns undef on _success_.
+    # Same parameters as rcs_commit_staged + 'rev', the patch ID to be
+    # reverted.
+    my %params = @_;
+    my $rev = $params{rev};
+
+    if(run_or_non('git', 'revert', '--no-commit', $rev)) {
+        debug "Committing revert for patch '$rev'.";
+        rcs_commit_staged(message => "This reverts commit $rev", @_);
+    } else {
+        # No idea what is actually getting reverted, so all we can do is say we failed.
+        run_or_die('git', 'reset', '--hard');
+        return "Failed to revert patch $rev.";
+    }
+}
+
+sub rcs_showpatch ($) {
+    # Show the patch with the given revision id.
+    my ($rev) = @_;
+
+    # FIXME check
+    my @r = run_or_die('git', 'show', $rev);
+
+    return join "\n", @r;
+}
 
 1