[PATCH 4/4] config: avoid calling `labs()` on too-large data type

From: Johannes Schindelin via GitGitGadget <gitgitgadget@gmail.com>
Date: Jun 13, 2019, 11:49 UTC
Message-ID: <9613c88849e53e00e1f7ade49c6c9056309ef0b9.1560426581.git.gitgitgadget@gmail.com>
In-Reply-To: <pull.265.git.gitgitgadget@gmail.com>

From: Johannes Schindelin <johannes.schindelin@gmx.de>

The `labs()` function operates, as the initial `l` suggests, on `long` parameters. However, in `config.c` we tried to use it on values of type `intmax_t`.

This problem was found by GCC v9.x.

To fix it, let's just "unroll" the function (i.e. negate the value if it is negative).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 config.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/config.c b/config.c
index 296a6d9cc4..01c6e9df23 100644
--- a/config.c
+++ b/config.c
@@ -869,9 +869,9 @@ static int git_parse_signed(const char *value, intmax_t *ret, intmax_t max)
 			errno = EINVAL;
 			return 0;
 		}
-		uval = labs(val);
+		uval = val < 0 ? -val : val;
 		uval *= factor;
-		if (uval > max || labs(val) > uval) {
+		if (uval > max || (val < 0 ? -val : val) > uval) {
 			errno = ERANGE;
 			return 0;
 		}

-- 
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