ext/sodium: avoid negations on unsigned values

jedisct1 · jedisct1 · commit 8a52a61e3a51 · 2017-09-21T17:46:01.000+02:00
diff --git a/ext/sodium/libsodium.c b/ext/sodium/libsodium.c
@@ -3284,7 +3284,7 @@ PHP_FUNCTION(sodium_unpad)
 			is_barrier =
 				(( (acc - 1U) & (pad_len - 1U) & ((c ^ 0x80) - 1U) ) >> 8) & 1U;
 			acc |= c;
-			pad_len |= (i & - is_barrier);
+			pad_len |= i & (1U + ~is_barrier);
 			valid |= (unsigned char) is_barrier;
 		}
 		unpadded_len = padded_len - 1U - pad_len;

Original file line number	Diff line number	Diff line change
`@@ -3284,7 +3284,7 @@ PHP_FUNCTION(sodium_unpad)`
`3284`	`3284`	`is_barrier =`
`3285`	`3285`	`(( (acc - 1U) & (pad_len - 1U) & ((c ^ 0x80) - 1U) ) >> 8) & 1U;`
`3286`	`3286`	`acc \|= c;`
`3287`		`- pad_len \|= (i & - is_barrier);`
	`3287`	`+ pad_len \|= i & (1U + ~is_barrier);`
`3288`	`3288`	`valid \|= (unsigned char) is_barrier;`
`3289`	`3289`	`}`
`3290`	`3290`	`unpadded_len = padded_len - 1U - pad_len;`