[PATCH] fix segfault with git log -c --follow
- From
Clemens Buchacher <drizzd@aon.at>
- Date
- May 27, 2013, 22:49 UTC
- Message-ID
- <20130527224957.GA7492@ecki>
In diff_tree_combined we make a copy of diffopts. In try_to_follow_renames, called via diff_tree_sha1, we free and re-initialize diffopts->pathspec->items. Since we did not make a deep copy of diffopts in diff_tree_combined, the original diffopts does not get the update. By the time we return from diff_tree_combined, rev->diffopt->pathspec->items points to an invalid memory address. We get a segfault next time we try to access that pathspec.
Instead, along with the copy of diffopts, make a copy pathspec->items as well.
We would also have to make a copy of pathspec->raw to keep it consistent with pathspec->items, but nobody seems to rely on that.
Signed-off-by: Clemens Buchacher <drizzd@aon.at> ---
I wonder why I get a segfault from this so reliably, since it's not actually a null-pointer dereference. Maybe this is gcc 4.8 doing something different from previous versions?
Also, I have absolutely no confidence in my understanding of this code. This is the first solution that came to mind, and could be totally wrong. I just figured a patch is better than no patch.
Clemens
combine-diff.c | 3 +++ t/t4202-log.sh | 14 ++++++++++++++ 2 files changed, 17 insertions(+)
diff --git a/combine-diff.c b/combine-diff.c index 77d7872..8825604 100644 --- a/combine-diff.c +++ b/combine-diff.c @@ -1302,6 +1302,7 @@ void diff_tree_combined(const unsigned char *sha1, int i, num_paths, needsep, show_log_first, num_parent = parents->nr; diffopts = *opt; + diff_tree_setup_paths(diffopts.pathspec.raw, &diffopts); diffopts.output_format = DIFF_FORMAT_NO_OUTPUT; DIFF_OPT_SET(&diffopts, RECURSIVE); DIFF_OPT_CLR(&diffopts, ALLOW_EXTERNAL); @@ -1372,6 +1373,8 @@ void diff_tree_combined(const unsigned char *sha1, paths = paths->next; free(tmp); } + + diff_tree_release_paths(&diffopts); } void diff_tree_combined_merge(const struct commit *commit, int dense, diff --git a/t/t4202-log.sh b/t/t4202-log.sh index 9243a97..cb03d28 100755 --- a/t/t4202-log.sh +++ b/t/t4202-log.sh @@ -530,6 +530,20 @@ test_expect_success 'show added path under "--follow -M"' ' ) ' +test_expect_success 'git log -c --follow' ' + test_create_repo follow-c && + ( + cd follow-c && + test_commit initial file original && + git rm file && + test_commit rename file2 original && + git reset --hard initial && + test_commit modify file foo && + git merge -m merge rename && + git log -c --follow file2 + ) +' + cat >expect <<\EOF * commit COMMIT_OBJECT_NAME |\ Merge: MERGE_PARENTS
-- 1.8.2.3