]> git.vanrenterghem.biz Git - git.ikiwiki.info.git/blobdiff - IkiWiki/Plugin/git.pm
git: Do the revert operation in a secondary working tree
[git.ikiwiki.info.git] / IkiWiki / Plugin / git.pm
index 5ec68b0ce4856f3e0dab7d2b65a00ee73aafd9fe..074026ff299a7d2c51b56a44be564e3b26104d59 100644 (file)
@@ -5,6 +5,7 @@ use warnings;
 use strict;
 use IkiWiki;
 use Encode;
+use File::Path qw{remove_tree};
 use URI::Escape q{uri_escape_utf8};
 use open qw{:utf8 :std};
 
@@ -153,17 +154,51 @@ sub genwrapper {
        }
 }
 
-my $git_dir=undef;
-my $prefix=undef;
+my @git_dir_stack;
+my $prefix;
 
 sub in_git_dir ($$) {
-       $git_dir=shift;
+       unshift @git_dir_stack, shift;
        my @ret=shift->();
-       $git_dir=undef;
+       shift @git_dir_stack;
        $prefix=undef;
        return @ret;
 }
 
+# Loosely based on git-new-workdir from git contrib.
+sub create_temp_working_dir ($$) {
+       my $rootdir = shift;
+       my $branch = shift;
+       my $working = "$rootdir/.git/ikiwiki-temp-working";
+       remove_tree($working);
+
+       foreach my $dir ("", ".git") {
+               if (!mkdir("$working/$dir")) {
+                       error("Unable to create $working/$dir: $!");
+               }
+       }
+
+       # Hooks are deliberately not included: we will commit to the temporary
+       # branch that is used in the temporary working tree, and we don't want
+       # to run the post-commit hook there.
+       #
+       # logs/refs is not included because we don't use the reflog.
+       # remotes, rr-cache, svn are similarly excluded.
+       foreach my $link ("config", "refs", "objects", "info", "packed-refs") {
+               if (!symlink("../../$link", "$working/.git/$link")) {
+                       error("Unable to create symlink $working/.git/$link: $!");
+               }
+       }
+
+       open (my $out, '>', "$working/.git/HEAD") or
+               error("failed to write $working.git/HEAD: $!");
+       print $out "ref: refs/heads/$branch\n" or
+               error("failed to write $working.git/HEAD: $!");
+       close $out or
+               error("failed to write $working.git/HEAD: $!");
+       return $working;
+}
+
 sub safe_git (&@) {
        # Start a child process safely without resorting to /bin/sh.
        # Returns command output (in list content) or success state
@@ -178,13 +213,13 @@ sub safe_git (&@) {
        if (!$pid) {
                # In child.
                # Git commands want to be in wc.
-               if (! defined $git_dir) {
+               if (! @git_dir_stack) {
                        chdir $config{srcdir}
                            or error("cannot chdir to $config{srcdir}: $!");
                }
                else {
-                       chdir $git_dir
-                           or error("cannot chdir to $git_dir: $!");
+                       chdir $git_dir_stack[0]
+                           or error("cannot chdir to $git_dir_stack[0]: $!");
                }
                exec @cmdline or error("Cannot exec '@cmdline': $!");
        }
@@ -425,6 +460,16 @@ sub parse_diff_tree ($) {
        }
        shift @{ $dt_ref } if $dt_ref->[0] =~ /^$/;
 
+       $ci{details} = [parse_changed_files($dt_ref)];
+
+       return \%ci;
+}
+
+sub parse_changed_files {
+       my $dt_ref = shift;
+
+       my @files;
+
        # Modified files.
        while (my $line = shift @{ $dt_ref }) {
                if ($line =~ m{^
@@ -442,7 +487,7 @@ sub parse_diff_tree ($) {
                        my $status = shift(@tmp);
 
                        if (length $file) {
-                               push @{ $ci{'details'} }, {
+                               push @files, {
                                        'file'      => decode_git_file($file),
                                        'sha1_from' => $sha1_from[0],
                                        'sha1_to'   => $sha1_to,
@@ -456,7 +501,7 @@ sub parse_diff_tree ($) {
                last;
        }
 
-       return \%ci;
+       return @files;
 }
 
 sub git_commit_info ($;$) {
@@ -600,18 +645,24 @@ sub rcs_commit_helper (@) {
                elsif (defined $params{session}->remote_addr()) {
                        $u=$params{session}->remote_addr();
                }
-               if (defined $u) {
+               if (length $u) {
                        $u=encode_utf8($u);
                        $ENV{GIT_AUTHOR_NAME}=$u;
                }
+               else {
+                       $u = 'anonymous';
+               }
                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) {
+               if (length $u) {
                        $ENV{GIT_AUTHOR_EMAIL}="$u\@web";
                }
+               else {
+                       $ENV{GIT_AUTHOR_EMAIL}='anonymous@web';
+               }
        }
 
        ensure_committer();
@@ -903,7 +954,7 @@ sub git_parse_changes {
                                die $@ if $@;
                                my $fh;
                                ($fh, $path)=File::Temp::tempfile(undef, UNLINK => 1);
-                               my $cmd = "cd $git_dir && ".
+                               my $cmd = "cd $git_dir_stack[0] && ".
                                          "git show $detail->{sha1_to} > '$path'";
                                if (system($cmd) != 0) {
                                        error("failed writing temp file '$path'.");
@@ -949,10 +1000,14 @@ sub rcs_preprevert ($) {
        my $rev=shift;
        my ($sha1) = $rev =~ /^($sha1_pattern)$/; # untaint
 
+       my @undo;      # undo stack for cleanup in case of an error
+
+       ensure_committer();
+
        # 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 {
+       return in_git_dir($rootdir, sub {
                my @commits=git_commit_info($sha1, 1);
        
                if (! @commits) {
@@ -965,7 +1020,66 @@ sub rcs_preprevert ($) {
                        error gettext("you are not allowed to revert a merge");
                }
 
+               # Due to the presence of rename-detection, we cannot actually
+               # see what will happen in a revert without trying it.
+               # But we can guess, which is enough to rule out most changes
+               # that we won't allow reverting.
                git_parse_changes(1, @commits);
+
+               my $failure;
+               my @ret;
+               eval {
+                       IkiWiki::disable_commit_hook();
+                       push @undo, sub {
+                               IkiWiki::enable_commit_hook();
+                       };
+                       my $branch = "ikiwiki_revert_${sha1}"; # supposed to be unique
+
+                       push @undo, sub {
+                               run_or_cry('git', 'branch', '-D', $branch) if $failure;
+                       };
+                       if (run_or_non('git', 'rev-parse', '--quiet', '--verify', $branch)) {
+                               run_or_non('git', 'branch', '-D', $branch);
+                       }
+                       run_or_die('git', 'branch', $branch, $config{gitmaster_branch});
+
+                       my $working = create_temp_working_dir($rootdir, $branch);
+
+                       push @undo, sub {
+                               remove_tree($working);
+                       };
+
+                       in_git_dir($working, sub {
+                               run_or_die('git', 'checkout', '--quiet', '--force', $branch);
+                               run_or_die('git', 'revert', '--no-commit', $sha1);
+                               run_or_die('git', 'commit', '-m', "revert $sha1", '-a');
+                       });
+
+                       my @raw_lines;
+                       @raw_lines = run_or_die('git', 'diff', '--pretty=raw',
+                               '--raw', '--abbrev=40', '--always', '--no-renames',
+                               "..${branch}");
+
+                       my $ci = {
+                               details => [parse_changed_files(\@raw_lines)],
+                       };
+
+                       @ret = git_parse_changes(0, $ci);
+               };
+               $failure = $@;
+
+               # Process undo stack (in reverse order).  By policy cleanup
+               # actions should normally print a warning on failure.
+               while (my $handle = pop @undo) {
+                       $handle->();
+               }
+
+               if ($failure) {
+                       my $message = sprintf(gettext("Failed to revert commit %s"), $sha1);
+                       error("$message\n$failure\n");
+               }
+
+               return @ret;
        });
 }
 
@@ -976,11 +1090,11 @@ sub rcs_revert ($) {
 
        ensure_committer();
 
-       if (run_or_non('git', 'revert', '--no-commit', $sha1)) {
+       if (run_or_non('git', 'merge', '--ff-only', "ikiwiki_revert_$sha1")) {
                return undef;
        }
        else {
-               run_or_die('git', 'reset', '--hard');
+               run_or_non('git', 'branch', '-D', "ikiwiki_revert_$sha1");
                return sprintf(gettext("Failed to revert commit %s"), $sha1);
        }
 }