From d60b0af5e32fed034bd163d244148947d3ed91a8 Mon Sep 17 00:00:00 2001 From: Jonathan Kew Date: Wed, 11 Sep 2019 12:07:46 +0000 Subject: Avoid undefined behavior (left-shifting negative value) in pixman_int_to_fixed Reported in https://bugzilla.mozilla.org/show_bug.cgi?id=1580352. Casting the argument to uint32_t should avoid invoking undefined behavior here. We'll still have *implementation-defined* behavior when casting the result back to pixman_fixed_t, but that's better than *undefined*. --- pixman/pixman.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/pixman/pixman.h b/pixman/pixman.h index 62dfb6a..8b38ba7 100644 --- a/pixman/pixman.h +++ b/pixman/pixman.h @@ -127,7 +127,7 @@ typedef pixman_fixed_16_16_t pixman_fixed_t; #define pixman_fixed_1_minus_e (pixman_fixed_1 - pixman_fixed_e) #define pixman_fixed_minus_1 (pixman_int_to_fixed(-1)) #define pixman_fixed_to_int(f) ((int) ((f) >> 16)) -#define pixman_int_to_fixed(i) ((pixman_fixed_t) ((i) << 16)) +#define pixman_int_to_fixed(i) ((pixman_fixed_t) ((uint32_t) (i) << 16)) #define pixman_fixed_to_double(f) (double) ((f) / (double) pixman_fixed_1) #define pixman_double_to_fixed(d) ((pixman_fixed_t) ((d) * 65536.0)) #define pixman_fixed_frac(f) ((f) & pixman_fixed_1_minus_e) -- cgit v1.2.1