@@ -274,11 +274,12 @@
 - (void)appendUTF8String: (const char*)UTF8String
 {
 	size_t UTF8StringLength = strlen(UTF8String);
 	size_t length;
 
-	if (UTF8StringLength >= 3 && !memcmp(UTF8String, "\xEF\xBB\xBF", 3)) {
+	if (UTF8StringLength >= 3 &&
+	    memcmp(UTF8String, "\xEF\xBB\xBF", 3) == 0) {
 		UTF8String += 3;
 		UTF8StringLength -= 3;
 	}
 
 	switch (of_string_utf8_check(UTF8String, UTF8StringLength, &length)) {
@@ -303,11 +304,12 @@
 - (void)appendUTF8String: (const char*)UTF8String
 		  length: (size_t)UTF8StringLength
 {
 	size_t length;
 
-	if (UTF8StringLength >= 3 && !memcmp(UTF8String, "\xEF\xBB\xBF", 3)) {
+	if (UTF8StringLength >= 3 &&
+	    memcmp(UTF8String, "\xEF\xBB\xBF", 3) == 0) {
 		UTF8String += 3;
 		UTF8StringLength -= 3;
 	}
 
 	switch (of_string_utf8_check(UTF8String, UTF8StringLength, &length)) {
@@ -673,11 +675,11 @@
 	newCStringLength = 0;
 	newLength = _s->length;
 
 	last = 0;
 	for (i = range.location; i <= range.length - searchLength; i++) {
-		if (memcmp(_s->cString + i, searchString, searchLength))
+		if (memcmp(_s->cString + i, searchString, searchLength) != 0)
 			continue;
 
 		@try {
 			newCString = [self
 			    resizeMemory: newCString