Fix accessing the contents of a direct string (#2261)

In the `ecma_string_get_chars` method
the contents of a direct string is accessed incorrectly.
It tries to extract the magic string id from the
string pointer but the direct string does not need
this step.

JerryScript-DCO-1.0-Signed-off-by: Peter Gal pgal.u-szeged@partner.samsung.com

jerry-core/ecma/base/ecma-helpers-string.c

@@ -1450,14 +1450,13 @@ ecma_string_get_chars (const ecma_string_t *string_p, /**< ecma-string */
         lit_magic_string_ex_id_t id = (lit_magic_string_ex_id_t) ECMA_GET_DIRECT_STRING_VALUE (string_p);
 
         size = lit_get_magic_string_ex_size (id);
+        result_p = lit_get_magic_string_ex_utf8 (id);
         length = 0;
 
         if (unlikely (*flags_p & ECMA_STRING_FLAG_IS_ASCII))
         {
-          length = lit_utf8_string_length (lit_get_magic_string_ex_utf8 (string_p->u.magic_string_ex_id), size);
+          length = lit_utf8_string_length (result_p, size);
         }
-
-        result_p = lit_get_magic_string_ex_utf8 (id);
         break;
       }
     }

tests/unit-core/test-api.c

@@ -1118,6 +1118,15 @@ main (void)
 
   jerry_release_value (args[0]);
 
+  const char *test_magic_str_access_src_p = "'console'.charAt(6) == 'e'";
+  res = jerry_eval ((const jerry_char_t *) test_magic_str_access_src_p,
+                    strlen (test_magic_str_access_src_p),
+                    false);
+  TEST_ASSERT (jerry_value_is_boolean (res));
+  TEST_ASSERT (jerry_get_boolean_value (res) == true);
+
+  jerry_release_value (res);
+
   cesu8_length = jerry_get_string_length (args[1]);
   cesu8_sz = jerry_get_string_size (args[1]);