Re: [PATCH] xsize_t: avoid implementation defined behavior when len < 0
From: Junio C Hamano <hidden>
Date: 2021-05-19 01:36:30
Possibly related (same subject, not in this thread)
- 2021-05-18 · [PATCH] xsize_t: avoid implementation defined behavior when len < 0 · Jonathan Nieder <hidden>
Jonathan Nieder [off-list ref] writes:
quoted hunk
Hi, This is *not* -rc material; it's just something I noticed and figured I would send it before I forget (among other benefits, this helps us kick the tires on the release candidate by having patches to work with). Thoughts welcome, as always. Jonathan git-compat-util.h | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)diff --git a/git-compat-util.h b/git-compat-util.h index a508dbe5a3..20318a0aac 100644 --- a/git-compat-util.h +++ b/git-compat-util.h@@ -986,11 +986,9 @@ static inline char *xstrdup_or_null(const char *str) static inline size_t xsize_t(off_t len) { - size_t size = (size_t) len; - - if (len != (off_t) size) + if (len < 0 || len > SIZE_MAX) die("Cannot handle files this big");
OK, so negative offset or offset that cannot be represented as size_t are rejected. That is much easier to read than the original ;-) SIZE_MAX is associated with size_t so it presumably is an unsigned constant; would it again trigger a sign-compare warning?
- return size; + return (size_t) len; } __attribute__((format (printf, 3, 4)))