Fix bug in jerry_string_to_char_buffer.

[jiangzidong]

Str_len can smaller than buffer_size.

  if (ecma_string_get_size (str_p) > buffer_size)
  {
    return 0;
  }

It should be ">" in the comparison.

And also change the related code in unit-test-api.c.
Before, in the foreach, it only sunk into

  if (sz == 0)
  {
    JERRY_ASSERT (!strncmp ((const char *) user_data, "user_data", 9));
    return true;
  }

JerryScript-DCO-1.0-Signed-off-by: Zidong Jiang [email protected]

[zherczeg]

LGTM

[LaszloLango]

LGTM

[LaszloLango]

@jiangzidong, please rebase to the current master, so we can land it properly.