reflog expire --stale-fix: be generous about missing objects

Whenever a user runs `git reflog expire --stale-fix`, the most likely
reason is that their repository is at least _somewhat_ corrupt. Which
means that it is more than just possible that some objects are missing.

If that is the case, that can currently let the command abort through
the phase where it tries to mark all reachable objects.

Instead of adding insult to injury, let's be gentle and continue as best
as we can in such a scenario, simply by ignoring the missing objects and
moving on.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/reflog.c b/builtin/reflog.c
index ca1d807..09541d1 100644 (file)
--- a/builtin/reflog.c
+++ b/builtin/reflog.c
@@ -602,6 +602,9 @@ static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
         */
        if (cb.cmd.stalefix) {
                repo_init_revisions(the_repository, &cb.cmd.revs, prefix);
+               cb.cmd.revs.do_not_die_on_missing_tree = 1;
+               cb.cmd.revs.ignore_missing = 1;
+               cb.cmd.revs.ignore_missing_links = 1;
                if (flags & EXPIRE_REFLOGS_VERBOSE)
                        printf(_("Marking reachable objects..."));
                mark_reachable_objects(&cb.cmd.revs, 0, 0, NULL);

diff --git a/t/t1410-reflog.sh b/t/t1410-reflog.sh
index ecccaa0..27b9080 100755 (executable)
--- a/t/t1410-reflog.sh
+++ b/t/t1410-reflog.sh
@@ -158,6 +158,32 @@ test_expect_success 'reflog expire' '
        check_fsck "dangling commit $K"
 '
 
+test_expect_success '--stale-fix handles missing objects generously' '
+       git -c core.logAllRefUpdates=false fast-import --date-format=now <<-EOS &&
+       commit refs/heads/stale-fix
+       mark :1
+       committer Author <a@uth.or> now
+       data <<EOF
+       start stale fix
+       EOF
+       M 100644 inline file
+       data <<EOF
+       contents
+       EOF
+       commit refs/heads/stale-fix
+       committer Author <a@uth.or> now
+       data <<EOF
+       stale fix branch tip
+       EOF
+       from :1
+       EOS
+
+       parent_oid=$(git rev-parse stale-fix^) &&
+       test_when_finished "recover $parent_oid" &&
+       corrupt $parent_oid &&
+       git reflog expire --stale-fix
+'
+
 test_expect_success 'prune and fsck' '
 
        git prune &&