X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/39b8931ad31fe6b48afdc570caa459a0996c2092..33b39968948f2dcda5c073916d797259e441d1de:/IkiWiki/Plugin/git.pm

diff --git a/IkiWiki/Plugin/git.pm b/IkiWiki/Plugin/git.pm
index 346808f04..0ee49416b 100644
--- a/IkiWiki/Plugin/git.pm
+++ b/IkiWiki/Plugin/git.pm
@@ -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};
 
@@ -164,12 +165,46 @@ sub in_git_dir ($$) {
 	return @ret;
 }
 
-sub safe_git (&@) {
+# 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
 	# (in scalar context), or runs the specified data handler.
 
-	my ($error_handler, $data_handler, @cmdline) = @_;
+	my %params = @_;
 
 	my $pid = open my $OUT, "-|";
 
@@ -186,7 +221,12 @@ sub safe_git (&@) {
 			chdir $git_dir_stack[0]
 			    or error("cannot chdir to $git_dir_stack[0]: $!");
 		}
-		exec @cmdline or error("Cannot exec '@cmdline': $!");
+
+		if ($params{stdout}) {
+			open(STDOUT, '>&', $params{stdout}) or error("Cannot reopen stdout: $!");
+		}
+
+		exec @{$params{cmdline}} or error("Cannot exec '@{$params{cmdline}}': $!");
 	}
 	# In parent.
 
@@ -201,24 +241,24 @@ sub safe_git (&@) {
 
 		chomp;
 
-		if (! defined $data_handler) {
+		if (! defined $params{data_handler}) {
 			push @lines, $_;
 		}
 		else {
-			last unless $data_handler->($_);
+			last unless $params{data_handler}->($_);
 		}
 	}
 
 	close $OUT;
 
-	$error_handler->("'@cmdline' failed: $!") if $? && $error_handler;
+	$params{error_handler}->("'@{$params{cmdline}}' failed: $!") if $? && $params{error_handler};
 
 	return wantarray ? @lines : ($? == 0);
 }
 # Convenient wrappers.
-sub run_or_die ($@) { safe_git(\&error, undef, @_) }
-sub run_or_cry ($@) { safe_git(sub { warn @_ }, undef, @_) }
-sub run_or_non ($@) { safe_git(undef, undef, @_) }
+sub run_or_die ($@) { safe_git(error_handler => \&error, cmdline => \@_) }
+sub run_or_cry ($@) { safe_git(error_handler => sub { warn @_ }, cmdline => \@_) }
+sub run_or_non ($@) { safe_git(cmdline => \@_) }
 
 sub ensure_committer {
 	if (! length $ENV{GIT_AUTHOR_NAME} || ! length $ENV{GIT_COMMITTER_NAME}) {
@@ -789,7 +829,11 @@ sub rcs_diff ($;$) {
 			if (@lines || $line=~/^diff --git/);
 		return 1;
 	};
-	safe_git(undef, $addlines, "git", "show", $sha1);
+	safe_git(
+		error_handler => undef,
+		data_handler => $addlines,
+		cmdline => ["git", "show", $sha1],
+	);
 	if (wantarray) {
 		return @lines;
 	}
@@ -919,11 +963,11 @@ sub git_parse_changes {
 				die $@ if $@;
 				my $fh;
 				($fh, $path)=File::Temp::tempfile(undef, UNLINK => 1);
-				my $cmd = "cd $git_dir_stack[0] && ".
-				          "git show $detail->{sha1_to} > '$path'";
-				if (system($cmd) != 0) {
-					error("failed writing temp file '$path'.");
-				}
+				safe_git(
+					error_handler => sub { error("failed writing temp file '$path': ".shift."."); },
+					stdout => $fh,
+					cmdline => ['git', 'show', $detail->{sha1_to}],
+				);
 			}
 
 			push @rets, {
@@ -993,7 +1037,6 @@ sub rcs_preprevert ($) {
 
 		my $failure;
 		my @ret;
-		# If it looks OK, do it for real, on a branch.
 		eval {
 			IkiWiki::disable_commit_hook();
 			push @undo, sub {
@@ -1009,23 +1052,22 @@ sub rcs_preprevert ($) {
 			}
 			run_or_die('git', 'branch', $branch, $config{gitmaster_branch});
 
+			my $working = create_temp_working_dir($rootdir, $branch);
+
 			push @undo, sub {
-				if (!run_or_cry('git', 'checkout', '--quiet', $config{gitmaster_branch})) {
-					run_or_cry('git', 'checkout','-f', '--quiet', $config{gitmaster_branch});
-				}
+				remove_tree($working);
 			};
-			run_or_die('git', 'checkout', '--quiet', $branch);
-
-			run_or_die('git', 'revert', '--no-commit', $sha1);
-			run_or_non('git', 'commit', '-m', "revert $sha1", '-a');
 
-			# Re-switch to master.
-			run_or_die('git', 'checkout', '--quiet', $config{gitmaster_branch});
+			in_git_dir($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',
-				"ikiwiki_revert_${sha1}..");
+				"..${branch}");
 
 			my $ci = {
 				details => [parse_changed_files(\@raw_lines)],