diff options
| author | Jeff King <peff@peff.net> | 2019-09-06 01:53:37 +0300 |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2019-09-06 21:03:39 +0300 |
| commit | e4b369069e4a7630233a045784d0b1e2425b0a05 (patch) | |
| tree | b8d944e9736c98e4dd6ca7a0c3e0a00bdafa0d6d /diff-delta.c | |
| parent | 7140414d8bd7ed1a05b83bc34d0d0e76ef8b12bd (diff) | |
diff-delta: set size out-parameter to 0 for NULL delta
When we cannot generate a delta, we return NULL but leave delta_size
untouched. This is generally OK, as callers rely on NULL to decide if
the output is usable or not. But it can confuse compilers; in
particular, gcc 9.2.1 with "-flto -O3" complains in fast-import's
store_object() that delta_len may be used uninitialized.
Let's change the diff-delta code to set the size explicitly to 0 for a
NULL return. That silences the compiler and makes it easier to reason
about the result.
Reported-by: Stephan Beyer <s-beyer@gmx.net>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'diff-delta.c')
| -rw-r--r-- | diff-delta.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/diff-delta.c b/diff-delta.c index e49643353b..77fea08dfb 100644 --- a/diff-delta.c +++ b/diff-delta.c @@ -326,6 +326,8 @@ create_delta(const struct delta_index *index, const unsigned char *ref_data, *ref_top, *data, *top; unsigned char *out; + *delta_size = 0; + if (!trg_buf || !trg_size) return NULL; |