[PATCH v4] reflog-walk: don't segfault on non-commit sha1's in the reflog
- From
Dennis Kaarsemaker <dennis@kaarsemaker.net>
- Date
- Jan 5, 2016, 21:12 UTC
- Message-ID
- <20160105211206.GA12057@spirit>
- In-Reply-To
- <1451552227.11138.6.camel@kaarsemaker.net>
git reflog (ab)uses the log machinery to display its list of log entries. To do so it must fake commit parent information for the log walker.
For refs in refs/heads this is no problem, as they should only ever point to commits. Tags and other refs however can point to anything, thus their reflog may contain non-commit objects.
To avoid segfaulting, we check whether reflog entries are commits before feeding them to the log walker and skip any non-commits. This means that git reflog output will be incomplete for such refs, but that's one step up from segfaulting. A more complete solution would be to decouple git reflog from the log walker machinery.
Signed-off-by: Dennis Kaarsemaker <dennis@kaarsemaker.net> Helped-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Helped-by: Junio C Hamano <gitster@pobox.com> --- Changes since v3: tweaks to the second test.
reflog-walk.c | 16 +++++++++++----- t/t1410-reflog.sh | 13 +++++++++++++ 2 files changed, 24 insertions(+), 5 deletions(-)
diff --git a/reflog-walk.c b/reflog-walk.c index 85b8a54..0ebd1da 100644 --- a/reflog-walk.c +++ b/reflog-walk.c @@ -221,6 +221,7 @@ void fake_reflog_parent(struct reflog_walk_info *info, struct commit *commit) struct commit_info *commit_info = get_commit_info(commit, &info->reflogs, 0); struct commit_reflog *commit_reflog; + struct object *logobj; struct reflog_info *reflog; info->last_commit_reflog = NULL; @@ -232,15 +233,20 @@ void fake_reflog_parent(struct reflog_walk_info *info, struct commit *commit) commit->parents = NULL; return; } - - reflog = &commit_reflog->reflogs->items[commit_reflog->recno]; info->last_commit_reflog = commit_reflog; - commit_reflog->recno--; - commit_info->commit = (struct commit *)parse_object(reflog->osha1); - if (!commit_info->commit) { + + do { + reflog = &commit_reflog->reflogs->items[commit_reflog->recno]; + commit_reflog->recno--; + logobj = parse_object(reflog->osha1); + } while (commit_reflog->recno && (logobj && logobj->type != OBJ_COMMIT)); + + if (!logobj || logobj->type != OBJ_COMMIT) { + commit_info->commit = NULL; commit->parents = NULL; return; } + commit_info->commit = (struct commit *)logobj; commit->parents = xcalloc(1, sizeof(struct commit_list)); commit->parents->item = commit_info->commit; diff --git a/t/t1410-reflog.sh b/t/t1410-reflog.sh index b79049f..17a194b 100755 --- a/t/t1410-reflog.sh +++ b/t/t1410-reflog.sh @@ -325,4 +325,17 @@ test_expect_success 'parsing reverse reflogs at BUFSIZ boundaries' ' test_cmp expect actual ' +test_expect_success 'no segfaults for reflog containing non-commit sha1s' ' + git update-ref --create-reflog -m "Creating ref" \ + refs/tests/tree-in-reflog HEAD && + git update-ref -m "Forcing tree" refs/tests/tree-in-reflog HEAD^{tree} && + git update-ref -m "Restoring to commit" refs/tests/tree-in-reflog HEAD && + git reflog refs/tests/tree-in-reflog +' + +test_expect_failure 'reflog with non-commit entries displays all entries' ' + git reflog refs/tests/tree-in-reflog >actual && + test_line_count = 3 actual +' + test_done
-- 2.7.0-rc3-219-g24972d4 -- Dennis Kaarsemaker <dennis@kaarsemaker.net> http://twitter.com/seveas