prefer "!=" when checking read_in_full() result

Comparing the result of read_in_full() using less-than is
potentially dangerous, as a negative return value may be
converted to an unsigned type and be considered a success.
This is discussed further in 561598cfcf (read_pack_header:
handle signed/unsigned comparison in read result,
2017-09-13).

Each of these instances is actually fine in practice:

 - in get-tar-commit-id, the HEADERSIZE macro expands to a
   signed integer. If it were switched to an unsigned type
   (e.g., a size_t), then it would be a bug.

 - the other two callers check for a short read only after
   handling a negative return separately. This is a fine
   practice, but we'd prefer to model "!=" as a general
   rule.

So all of these cases can be considered cleanups and not
actual bugfixes.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Jeff King
2017-09-27 02:00:28 -04:00
committed by Junio C Hamano
parent a1f3515da7
commit 61d36330b4
3 changed files with 3 additions and 3 deletions

View File

@ -19,7 +19,7 @@ static void flush(struct sha1file *f, const void *buf, unsigned int count)
if (ret < 0)
die_errno("%s: sha1 file read error", f->name);
if (ret < count)
if (ret != count)
die("%s: sha1 file truncated", f->name);
if (memcmp(buf, check_buffer, count))
die("sha1 file '%s' validation error", f->name);