Add more string test cases.

This adds test cases for the rest of our ASCII string functions.  While
doing so, it fixes two minor bugs:
- strcasecmp() now handles utf8 correctly
- strncpy() no longer does the stpncpy() behavior of clearing leftover
  buffer

Signed-off-by: Peter Jones <pjones@redhat.com>

include/test.h

@@ -213,6 +213,20 @@ extern int debug;
 		}                                                          \
 	})
 
+#define assert_negative_goto(a, label, fmt, ...)                              \
+	({                                                                    \
+		int rc_ = assert_negative_as_expr(a, -1, fmt, ##__VA_ARGS__); \
+		if (rc_ != 0)                                                 \
+			goto label;                                           \
+	})
+
+#define assert_positive_goto(a, label, fmt, ...)                              \
+	({                                                                    \
+		int rc_ = assert_positive_as_expr(a, -1, fmt, ##__VA_ARGS__); \
+		if (rc_ != 0)                                                 \
+			goto label;                                           \
+	})
+
 #define test(x, ...)                                    \
 	({                                              \
 		int rc;                                 \

lib/string.c

@@ -13,6 +13,7 @@
 #define strcasecmp shim_strcasecmp
 #define strrchr shim_strrchr
 #define strlen shim_strlen
+#define strnlen shim_strnlen
 #define strcpy shim_strcpy
 #define strncpy shim_strncpy
 #define strdup shim_strdup
@@ -93,7 +94,7 @@ strncasecmp(const char *s1p, const char *s2p, size_t n)
 int
 strcasecmp(const char *str1, const char *str2)
 {
-	char c1, c2;
+	uint8_t c1, c2;
 
 	c1 = toupper(*str1);
 	c2 = toupper(*str2);
@@ -155,7 +156,7 @@ strncpy(char *dest, const char *src, size_t n)
 
 	for (i = 0; i < n && src[i] != '\0'; i++)
 		dest[i] = src[i];
-	for (; i < n; i++)
+	if (i < n)
 		dest[i] = '\0';
 
 	return dest;