From: Simon McVittie Date: Wed, 28 Dec 2016 18:04:34 +0000 (+0000) Subject: git: Do the revert operation in a secondary working tree X-Git-Tag: debian/3.20120629.2+deb7u2~21 X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/commitdiff_plain/339f15d6f4a2d22014e2d38b7459de8a28c5fa8f git: Do the revert operation in a secondary working tree This avoids leaving the git directory in an inconsistent state if the host system is rebooted while we are processing a revert. (cherry picked from commit 7e84a1f9d88a1f546188a28524fedbdf53bb8729) --- diff --git a/IkiWiki/Plugin/git.pm b/IkiWiki/Plugin/git.pm index 809f82f52..074026ff2 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}; @@ -164,6 +165,40 @@ sub in_git_dir ($$) { return @ret; } +# Loosely based on git-new-workdir from git contrib. +sub create_temp_working_dir ($$) { + 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 $working; +} + sub safe_git (&@) { # Start a child process safely without resorting to /bin/sh. # Returns command output (in list content) or success state @@ -993,7 +1028,6 @@ sub rcs_preprevert ($) { my $failure; my @ret; - # If it looks OK, do it for real, on a branch. eval { IkiWiki::disable_commit_hook(); push @undo, sub { @@ -1009,23 +1043,22 @@ sub rcs_preprevert ($) { } 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)],