scc

commit 44a3fd53a73262f822613097d7b6a01c70320ba3
parent 75b05d85411ef3d37ef3ab460f1e12c2960cb6a8
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Sun, 16 Sep 2018 06:40:50 +0100

[lib/c] Fix memcmp()

Char can be signed and the substraction of signed types can produce
unexpected results if it doesn't fit in an integer.

Diffstat:
M
lib/c/memcmp.c
 | 
7
++++---

1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/lib/c/memcmp.c b/lib/c/memcmp.c
@@ -4,9 +4,10 @@
 int
 memcmp(const void *s1, const void *s2, size_t n)
 {
-	char *s = (char *) s1, *t = (char *) s2;
+	const unsigned char *s = (unsigned char *) s1;
+	const unsigned char *t = (unsigned char *) s2;
 
-	while (n > 0 && *s == *t)
-		--n, ++s, ++t;
+	for ( ; n > 0 && *s++ == *t++; --n)
+		;
 	return n ? (*s - *t) : 0;
 }