# [PATCH] Check for large pack offsets could be optimized away

1 messages from 2007-08-16 to 2007-08-16. Participants: Marco Costalba.
Thread: https://gitlist.dev/t/9551

## Marco Costalba, 2007-08-16 07:58

Subject: [PATCH] Check for large pack offsets could be optimized away
Message-ID: <e5bfff550708160058q6674f832m641647cd883accfc@mail.gmail.com>
URL: https://gitlist.dev/e/e5bfff550708160058q6674f832m641647cd883accfc%40mail.gmail.com

```
Without this fix gcc 4.2.1 warns with:

warning: assuming signed overflow does not occur
when assuming that (X + c) < X is always false

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
---
 sha1_file.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/sha1_file.c b/sha1_file.c
index b219d4d..ba29000 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -524,7 +524,8 @@ static int check_packed_git_idx
 		if (idx_size != min_size) {
 			/* make sure we can deal with large pack offsets */
 			off_t x = 0x7fffffffUL, y = 0xffffffffUL;
-			if (x > (x + 1) || y > (y + 1)) {
+			off_t x1 = x + 1, y1 = y + 1;
+			if (x > x1 || y > y1) {
  				munmap(idx_map, idx_size);
 				return error("pack too large for current definition of off_t in %s", path);
 			}
-- 
1.5.3.rc4.67.gf9286

```