nice message if someone tries to revert a merge commit

[ikiwiki.git] / IkiWiki / Plugin / git.pm

diff --git a/IkiWiki/Plugin/git.pm b/IkiWiki/Plugin/git.pm
index 794afb74065ab919f942a88799a61db24eb1476d..f5101d904012b8472c1cf77d143ee218f0e32f59 100644 (file)
--- a/IkiWiki/Plugin/git.pm
+++ b/IkiWiki/Plugin/git.pm
@@ -9,7 +9,7 @@ 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;
+my $git_dir=undef;
 
 sub import {
        hook(type => "checkconfig", id => "git", call => \&checkconfig);
@@ -29,7 +29,6 @@ sub import {
        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);
 }
 
 sub checkconfig () {
@@ -165,9 +164,13 @@ 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': $!");
        }
@@ -722,14 +725,13 @@ sub rcs_getmtime ($) {
 }
 
 {
-my $git_root;
-
+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 $git_root if defined $git_root;
+       return @$ret if defined $ret;
        
        my $subdir="";
        my $dir=$config{srcdir};
@@ -741,7 +743,8 @@ sub git_find_root {
                }
        }
 
-       return $subdir;
+       $ret=[$subdir, $dir];
+       return @$ret;
 }
 
 }
@@ -749,7 +752,7 @@ sub git_find_root {
 sub git_parse_changes {
        my @changes = @_;
 
-       my $subdir = git_find_root();
+       my ($subdir, $rootdir) = git_find_root();
        my @rets;
        foreach my $ci (@changes) {
                foreach my $detail (@{ $ci->{'details'} }) {
@@ -795,10 +798,8 @@ sub git_parse_changes {
                                die $@ if $@;
                                my $fh;
                                ($fh, $path)=File::Temp::tempfile("XXXXXXXXXX", UNLINK => 1);
-                               # Ensure we run this in the right place,
-                               # see comments in rcs_receive.
-                               my $cmd = ($no_chdir ? '' : "cd $config{srcdir} && ")
-                                       . "git show $detail->{sha1_to} > '$path'";
+                               my $cmd = "cd $git_dir && ".
+                                         "git show $detail->{sha1_to} > '$path'";
                                if (system($cmd) != 0) {
                                        error("failed writing temp file '$path'.");
                                }
@@ -828,49 +829,53 @@ sub rcs_receive () {
 
                # Avoid chdir when running git here, because the changes
                # are in the master git repo, not the srcdir repo.
+               # (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.
-               $no_chdir=1;
+               $git_dir=".";
                push @rets, git_parse_changes(git_commit_info($oldrev."..".$newrev));
-               $no_chdir=0;
+               $git_dir=undef;
        }
 
        return reverse @rets;
 }
 
-sub rcs_preprevert (@) {
-       my %params = @_;
-       my $rev = $params{rev};
+sub rcs_preprevert ($) {
+       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();
+       $git_dir=$rootdir;
+       my @commits=git_commit_info($sha1, 1);
+       $git_dir=undef;
+
+       if (! @commits) {
+               error "unknown commit"; # just in case
+       }
+
+       # 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");
+       }
 
-       # Note test_changes expects 'cgi' and 'session' parameters.
-       require IkiWiki::Receive;
-       IkiWiki::Receive::test_changes(%params, changes =>
-               [git_parse_changes(git_commit_info($rev, 1))]);
+       return git_parse_changes(@commits);
 }
 
-sub rcs_revert (@) {
-       # Try to revert the given patch; returns undef on _success_.
-       my %params = @_;
-       my $rev = $params{rev};
+sub rcs_revert ($) {
+       # 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', $rev)) {
-               debug "Committing revert for patch '$rev'.";
-               rcs_commit_staged(message => 
-                       sprintf(gettext("This reverts commit %s"), $rev), @_);
+       if (run_or_non('git', 'revert', '--no-commit', $sha1)) {
+               return undef;
        }
        else {
-               # No idea what is actually getting reverted, so all we can
-               # do is say we failed.
                run_or_die('git', 'reset', '--hard');
-               return sprintf(gettext("Failed to revert commit %s"), $rev);
+               return sprintf(gettext("Failed to revert commit %s"), $sha1);
        }
 }
 
-sub rcs_showpatch (@) {
-       # Show the patch with the given revision id.
-       my %params = @_;
-       my $rev = $params{rev};
-
-       return join "\n", run_or_die('git', 'show', $rev);
-}
-
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