]> git.vanrenterghem.biz Git - git.ikiwiki.info.git/blobdiff - IkiWiki/Plugin/git.pm
Forum: Ask about strange link appearance with trail and actiontabs
[git.ikiwiki.info.git] / IkiWiki / Plugin / git.pm
index aa402c04f4e461b9450a0192313de1dda8726f49..75b89e476bbb4bf1da262385a8e390994489f0e9 100644 (file)
@@ -5,11 +5,11 @@ use warnings;
 use strict;
 use IkiWiki;
 use Encode;
+use URI::Escape q{uri_escape_utf8};
 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 {
        hook(type => "checkconfig", id => "git", call => \&checkconfig);
@@ -27,6 +27,10 @@ sub import {
        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_find_changes", call => \&rcs_find_changes);
+       hook(type => "rcs", id => "rcs_get_current_rev", call => \&rcs_get_current_rev);
 }
 
 sub checkconfig () {
@@ -41,11 +45,14 @@ sub checkconfig () {
                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}) {
+           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},
@@ -78,6 +85,13 @@ sub getsetup () {
                        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',
@@ -101,7 +115,7 @@ sub getsetup () {
                },
                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,
@@ -139,11 +153,23 @@ sub genwrapper {
        }
 }
 
+my $git_dir=undef;
+my $prefix=undef;
+
+sub in_git_dir ($$) {
+       $git_dir=shift;
+       my @ret=shift->();
+       $git_dir=undef;
+       $prefix=undef;
+       return @ret;
+}
+
 sub safe_git (&@) {
-       # Start a child process safely without resorting /bin/sh.
-       # Return command output or success state (in scalar context).
+       # Start a child process safely without resorting to /bin/sh.
+       # Returns command output (in list content) or success state
+       # (in scalar context), or runs the specified data handler.
 
-       my ($error_handler, @cmdline) = @_;
+       my ($error_handler, $data_handler, @cmdline) = @_;
 
        my $pid = open my $OUT, "-|";
 
@@ -152,9 +178,13 @@ sub safe_git (&@) {
        if (!$pid) {
                # In child.
                # Git commands want to be in wc.
-               if (! $no_chdir) {
+               if (! defined $git_dir) {
                        chdir $config{srcdir}
-                           or error("Cannot chdir to $config{srcdir}: $!");
+                           or error("cannot chdir to $config{srcdir}: $!");
+               }
+               else {
+                       chdir $git_dir
+                           or error("cannot chdir to $git_dir: $!");
                }
                exec @cmdline or error("Cannot exec '@cmdline': $!");
        }
@@ -171,7 +201,12 @@ sub safe_git (&@) {
 
                chomp;
 
-               push @lines, $_;
+               if (! defined $data_handler) {
+                       push @lines, $_;
+               }
+               else {
+                       last unless $data_handler->($_);
+               }
        }
 
        close $OUT;
@@ -181,9 +216,9 @@ sub safe_git (&@) {
        return wantarray ? @lines : ($? == 0);
 }
 # Convenient wrappers.
-sub run_or_die ($@) { safe_git(\&error, @_) }
-sub run_or_cry ($@) { safe_git(sub { warn @_ },  @_) }
-sub run_or_non ($@) { safe_git(undef,            @_) }
+sub run_or_die ($@) { safe_git(\&error, undef, @_) }
+sub run_or_cry ($@) { safe_git(sub { warn @_ }, undef, @_) }
+sub run_or_non ($@) { safe_git(undef, undef, @_) }
 
 
 sub merge_past ($$$) {
@@ -280,15 +315,36 @@ sub merge_past ($$$) {
        return $conflict;
 }
 
-sub parse_diff_tree ($@) {
+sub decode_git_file ($) {
+       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;
+       }
+
+       # 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 } ||
-                 !defined @{ $dt_ref }[0] || !length @{ $dt_ref }[0];
+       return if ! @{ $dt_ref } ||
+                 !defined $dt_ref->[0] || !length $dt_ref->[0];
 
        my %ci;
        # Header line.
@@ -318,8 +374,9 @@ 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"} = $1;
@@ -367,16 +424,9 @@ sub parse_diff_tree ($@) {
                        my $sha1_to = shift(@tmp);
                        my $status = shift(@tmp);
 
-                       # 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;
-                       }
-                       $file =~ s/^\Q$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' => $mode_from[0],
@@ -403,10 +453,9 @@ sub git_commit_info ($;$) {
        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;
        }
 
@@ -415,27 +464,70 @@ sub git_commit_info ($;$) {
        return wantarray ? @ci : $ci[0];
 }
 
-sub git_sha1 (;$) {
-       # Return head sha1sum (of given file).
-       my $file = shift || q{--};
+sub rcs_find_changes ($) {
+       my $oldrev=shift;
+
+       # Note that git log will sometimes show files being added that
+       # don't exist. Particularly, git merge -s ours can result in a
+       # merge commit where some files were not really added.
+       # This is why the code below verifies that the files really
+       # exist.
+       my @raw_lines = run_or_die('git', 'log',
+               '--pretty=raw', '--raw', '--abbrev=40', '--always', '-c',
+               '--no-renames', , '--reverse',
+               '-r', "$oldrev..HEAD", '--', '.');
+
+       # Due to --reverse, we see changes in chronological order.
+       my %changed;
+       my %deleted;
+       my $nullsha = 0 x 40;
+       my $newrev=$oldrev;
+       while (my $ci = parse_diff_tree(\@raw_lines)) {
+               $newrev=$ci->{sha1};
+               foreach my $i (@{$ci->{details}}) {
+                       my $file=$i->{file};
+                       if ($i->{sha1_to} eq $nullsha) {
+                               if (! -e "$config{srcdir}/$file") {
+                                       delete $changed{$file};
+                                       $deleted{$file}=1;
+                               }
+                       }
+                       else {
+                               if (-e "$config{srcdir}/$file") {
+                                       delete $deleted{$file};
+                                       $changed{$file}=1;
+                               }
+                       }
+               }
+       }
 
+       return (\%changed, \%deleted, $newrev);
+}
+
+sub git_sha1_file ($) {
+       my $file=shift;
+       git_sha1("--", $file);
+}
+
+sub git_sha1 (@) {
        # Ignore error since a non-existing file might be given.
        my ($sha1) = run_or_non('git', 'rev-list', '--max-count=1', 'HEAD',
-               '--', $file);
-       if ($sha1) {
+               '--', @_);
+       if (defined $sha1) {
                ($sha1) = $sha1 =~ m/($sha1_pattern)/; # sha1 is untainted now
        }
-       else {
-               debug("Empty sha1sum for '$file'.");
-       }
-       return defined $sha1 ? $sha1 : q{};
+       return defined $sha1 ? $sha1 : '';
+}
+
+sub rcs_get_current_rev () {
+       git_sha1();
 }
 
 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});
        }
 }
 
@@ -444,62 +536,89 @@ sub rcs_prepedit ($) {
        # This will be later used in rcs_commit if a merge is required.
        my ($file) = @_;
 
-       return git_sha1($file);
+       return git_sha1_file($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 $cur    = git_sha1_file($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);
+       return rcs_commit_helper(@_);
 }
 
-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)=@_;
+       return rcs_commit_helper(@_);
+}
 
-       # Set the commit author and email to the web committer.
+sub rcs_commit_helper (@) {
+       my %params=@_;
+       
        my %env=%ENV;
-       if (defined $user || defined $ipaddr) {
-               my $u=encode_utf8(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";
+               }
        }
 
-       $message = IkiWiki::possibly_foolish_untaint($message);
+       $params{message} = IkiWiki::possibly_foolish_untaint($params{message});
        my @opts;
-       if ($message !~ /\S/) {
+       if ($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") {
+               if ($version ge "1.7.8") {
+                       push @opts, "--allow-empty-message", "--no-edit";
+               }
+               if ($version ge "1.7.2") {
+                       push @opts, "--allow-empty-message";
+               }
+               elsif ($version ge "1.5.4") {
                        push @opts, '--cleanup=verbatim';
                }
                else {
-                       $message.=".";
+                       $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).
-       if (run_or_non('git', 'commit', @opts, '-m', $message)) {
+       if (exists $params{file}) {
+               push @opts, '--', $params{file};
+       }
+       # git commit returns non-zero if nothing really changed.
+       # So we should ignore its exit status (hence run_or_non).
+       if (run_or_non('git', 'commit', '-m', $params{message}, '-q', @opts)) {
                if (length $config{gitorigin_branch}) {
-                       run_or_cry('git', 'push', $config{gitorigin_branch});
+                       run_or_cry('git', 'push', $config{gitorigin_branch}, $config{gitmaster_branch});
                }
        }
        
@@ -550,9 +669,12 @@ sub rcs_recentchanges ($) {
                my @pages;
                foreach my $detail (@{ $ci->{'details'} }) {
                        my $file = $detail->{'file'};
+                       my $efile = join('/',
+                               map { uri_escape_utf8($_) } split('/', $file)
+                       );
 
                        my $diffurl = defined $config{'diffurl'} ? $config{'diffurl'} : "";
-                       $diffurl =~ s/\[\[file\]\]/$file/go;
+                       $diffurl =~ s/\[\[file\]\]/$efile/go;
                        $diffurl =~ s/\[\[sha1_parent\]\]/$ci->{'parent'}/go;
                        $diffurl =~ s/\[\[sha1_from\]\]/$detail->{'sha1_from'}/go;
                        $diffurl =~ s/\[\[sha1_to\]\]/$detail->{'sha1_to'}/go;
@@ -574,7 +696,16 @@ sub rcs_recentchanges ($) {
 
                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 $messages[0] &&
@@ -587,6 +718,7 @@ sub rcs_recentchanges ($) {
                push @rets, {
                        rev        => $sha1,
                        user       => $user,
+                       nickname   => $nickname,
                        committype => $web_commit ? "web" : "git",
                        when       => $when,
                        message    => [@messages],
@@ -599,15 +731,19 @@ sub rcs_recentchanges ($) {
        return @rets;
 }
 
-sub rcs_diff ($) {
+sub rcs_diff ($;$) {
        my $rev=shift;
+       my $maxlines=shift;
        my ($sha1) = $rev =~ /^($sha1_pattern)$/; # untaint
        my @lines;
-       foreach my $line (run_or_non("git", "show", $sha1)) {
-               if (@lines || $line=~/^diff --git/) {
-                       push @lines, $line."\n";
-               }
-       }
+       my $addlines=sub {
+               my $line=shift;
+               return if defined $maxlines && @lines == $maxlines;
+               push @lines, $line."\n"
+                       if (@lines || $line=~/^diff --git/);
+               return 1;
+       };
+       safe_git(undef, $addlines, "git", "show", $sha1);
        if (wantarray) {
                return @lines;
        }
@@ -623,13 +759,10 @@ sub findtimes ($$) {
        my $file=shift;
        my $id=shift; # 0 = mtime ; 1 = ctime
 
-       # Remove srcdir prefix
-       $file =~ s/^\Q$config{srcdir}\E\/?//;
-
        if (! keys %time_cache) {
                my $date;
                foreach my $line (run_or_die('git', 'log',
-                               '--pretty=format:%ct',
+                               '--pretty=format:%at',
                                '--name-only', '--relative')) {
                        if (! defined $date && $line =~ /^(\d+)$/) {
                                $date=$line;
@@ -638,10 +771,12 @@ sub findtimes ($$) {
                                $date=undef;
                        }
                        else {
-                               if (! $time_cache{$line}) {
-                                       $time_cache{$line}[0]=$date; # mtime
+                               my $f=decode_git_file($line);
+
+                               if (! $time_cache{$f}) {
+                                       $time_cache{$f}[0]=$date; # mtime
                                }
-                               $time_cache{$line}[1]=$date; # ctime
+                               $time_cache{$f}[1]=$date; # ctime
                        }
                }
        }
@@ -663,10 +798,15 @@ sub rcs_getmtime ($) {
        return findtimes($file, 0);
 }
 
-sub rcs_receive () {
+{
+my $ret;
+sub git_find_root {
        # The wiki may not be the only thing in the git repo.
        # Determine if it is in a subdirectory by examining the srcdir,
        # and its parents, looking for the .git directory.
+
+       return @$ret if defined $ret;
+       
        my $subdir="";
        my $dir=$config{srcdir};
        while (! -d "$dir/.git") {
@@ -677,83 +817,140 @@ sub rcs_receive () {
                }
        }
 
+       $ret=[$subdir, $dir];
+       return @$ret;
+}
+
+}
+
+sub git_parse_changes {
+       my $reverted = shift;
+       my @changes = @_;
+
+       my ($subdir, $rootdir) = git_find_root();
+       my @rets;
+       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= $reverted ? "remove" : "add";
+                               $mode=$detail->{'mode_to'};
+                       }
+                       elsif ($detail->{'status'} =~ /^[DAM]+\d*/) {
+                               $action= $reverted ? "add" : "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(undef, UNLINK => 1);
+                               my $cmd = "cd $git_dir && ".
+                                         "git show $detail->{sha1_to} > '$path'";
+                               if (system($cmd) != 0) {
+                                       error("failed writing temp file '$path'.");
+                               }
+                       }
+
+                       push @rets, {
+                               file => $file,
+                               action => $action,
+                               path => $path,
+                       };
+               }
+       }
+
+       return @rets;
+}
+
+sub rcs_receive () {
        my @rets;
        while (<>) {
                chomp;
                my ($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"), $file);
-                               }
+               # (Also, if a subdir is involved, we don't want to chdir to
+               # it and only see changes in it.)
+               # The pre-receive hook already puts us in the right place.
+               in_git_dir(".", sub {
+                       push @rets, git_parse_changes(0, git_commit_info($oldrev."..".$newrev));
+               });
+       }
 
-                               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");
-                                       }
-                               }
+       return reverse @rets;
+}
 
-                               push @rets, {
-                                       file => $file,
-                                       action => $action,
-                                       path => $path,
-                               };
-                       }
+sub rcs_preprevert ($) {
+       my $rev=shift;
+       my ($sha1) = $rev =~ /^($sha1_pattern)$/; # untaint
+
+       # Examine changes from root of git repo, not from any subdir,
+       # in order to see all changes.
+       my ($subdir, $rootdir) = git_find_root();
+       in_git_dir($rootdir, sub {
+               my @commits=git_commit_info($sha1, 1);
+       
+               if (! @commits) {
+                       error "unknown commit"; # just in case
                }
-       }
 
-       return reverse @rets;
+               # git revert will fail on merge commits. Add a nice message.
+               if (exists $commits[0]->{parents} &&
+                   @{$commits[0]->{parents}} > 1) {
+                       error gettext("you are not allowed to revert a merge");
+               }
+
+               git_parse_changes(1, @commits);
+       });
+}
+
+sub rcs_revert ($) {
+       # Try to revert the given rev; returns undef on _success_.
+       my $rev = shift;
+       my ($sha1) = $rev =~ /^($sha1_pattern)$/; # untaint
+
+       if (run_or_non('git', 'revert', '--no-commit', $sha1)) {
+               return undef;
+       }
+       else {
+               run_or_die('git', 'reset', '--hard');
+               return sprintf(gettext("Failed to revert commit %s"), $sha1);
+       }
 }
 
 1