Fix bug detected by scan-build

m-string.h

@@ -982,7 +982,7 @@ static inline size_t
 string_length_u(string_t str)
 {
   STRING_CONTRACT(str);
-  return stringi_utf8_length(str->ptr);
+  return stringi_utf8_length(string_get_cstr(str));
 }
 
 /* Check if a string is a valid UTF8 encoded stream */
@@ -990,7 +990,7 @@ static inline bool
 string_utf8_p(string_t str)
 {
   STRING_CONTRACT(str);
-  return stringi_utf8_valid_str_p(str->ptr);
+  return stringi_utf8_valid_str_p(string_get_cstr(str));
 }
 
 

tests/test-mstring.c

@@ -36,6 +36,9 @@ static void test_utf8_basic(void)
 {
   string_t s;
   string_init (s);
+
+  assert (string_utf8_p(s) == true);
+  assert (string_length_u(s) == 0);
   
   /* Test internal encode + decode for all characters */
   for (string_unicode_t i = 1; i < 0x10ffff; i++) {