shared: add strcmp() testcases, fix invalid implementation

2 files changed, 13 insertions, 6 deletions

diff --git a/src/kernel/tests/util.c b/src/kernel/tests/util.c
index 05bba24..e7dcb82 100644
--- a/src/kernel/tests/util.c
+++ b/src/kernel/tests/util.c
@@ -22,6 +22,15 @@ TEST(memcmp) {
 	TEST_COND(0 < memcmp("654", "555", 3));
 }
 
+TEST(strcmp) {
+	TEST_COND(0 == strcmp("string", "string"));
+	TEST_COND(0 > strcmp("str", "string"));
+	TEST_COND(0 < strcmp("string", "str"));
+
+	TEST_COND(0 != strcmp("stress", "string"));
+}
+
 void tests_utils(void) {
 	TEST_RUN(memcmp);
+	TEST_RUN(strcmp);
 }
diff --git a/src/shared/mem.c b/src/shared/mem.c
index 9185c9e..eb34445 100644
--- a/src/shared/mem.c
+++ b/src/shared/mem.c
@@ -28,14 +28,12 @@ void *memset(void *s, int c, size_t n) {
 }
 
 int strcmp(const char *s1, const char *s2) {
-	while (*s1) {
-		if (*s1 != *s2) {
-			if (*s1 < *s2)  return -1;
-			else            return 1;
-		}
+	while (*s1 && *s1 == *s2) {
 		s1++; s2++;
 	}
-	return 0;
+	if (*s1 == *s2) return  0;
+	if (*s1 <  *s2) return -1;
+	else            return  1;
 }
 
 size_t strlen(const char *s) {