commit-graph: verify swapped zero/non-zero generation cases

In verify_one_commit_graph(), we have code that complains when a commit
is found with a generation number of zero, and then later with a
non-zero number. It works like this:

  1. When we see an entry with generation zero, we set the
     generation_zero flag to GENERATION_ZERO_EXISTS.

  2. When we later see an entry with a non-zero generation, we complain
     if the flag is GENERATION_ZERO_EXISTS.

There's a matching GENERATION_NUMBER_EXISTS value, which in theory would
be used to find the case that we see the entries in the opposite order:

  1. When we see an entry with a non-zero generation, we set the
     generation_zero flag to GENERATION_NUMBER_EXISTS.

  2. When we later see an entry with a zero generation, we complain if
     the flag is GENERATION_NUMBER_EXISTS.

But that doesn't work; step 2 is implemented, but there is no step 1. We
never use NUMBER_EXISTS at all, and Coverity rightly complains that step
2 is dead code.

We can fix that by implementing that step 1.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
maint
Jeff King 2023-08-21 17:34:37 -04:00 committed by Junio C Hamano
parent 868c991155
commit cc9c9a00a5
1 changed files with 6 additions and 3 deletions

View File

@ -2686,9 +2686,12 @@ static int verify_one_commit_graph(struct repository *r,
graph_report(_("commit-graph has generation number zero for commit %s, but non-zero elsewhere"),
oid_to_hex(&cur_oid));
generation_zero = GENERATION_ZERO_EXISTS;
} else if (generation_zero == GENERATION_ZERO_EXISTS)
graph_report(_("commit-graph has non-zero generation number for commit %s, but zero elsewhere"),
oid_to_hex(&cur_oid));
} else {
if (generation_zero == GENERATION_ZERO_EXISTS)
graph_report(_("commit-graph has non-zero generation number for commit %s, but zero elsewhere"),
oid_to_hex(&cur_oid));
generation_zero = GENERATION_NUMBER_EXISTS;
}

if (generation_zero == GENERATION_ZERO_EXISTS)
continue;