rerere: fix crashes due to unmatched opening conflict markers

When rerere handles a conflict with an unmatched opening conflict marker
in a file with other conflicts, it will fail create a preimage and also
fail allocate the status member of struct rerere_dir. Currently the
status member is allocated after the error handling. This will lead to a
SEGFAULT when the status member is accessed during cleanup of the failed
parse.

Additionally, in subsequent executions of rerere, after removing the
MERGE_RR.lock manually, rerere crashes for a similar reason. MERGE_RR
points to a conflict id that has no preimage, therefore the status
member is not allocated and a SEGFAULT happens when trying to check if a
preimage exists.

Solve this by making sure the status field is allocated correctly and add
tests to prevent the bug from reoccurring.

This does not fix the root cause, failing to parse stray conflict
markers, but I don't think we can do much better than recognizing it,
printing an error, and moving on gracefully.

Signed-off-by: Marcel Röthke <marcel@roethke.info>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

0 files changed, 0 insertions, 0 deletions