The "end" argument is unusual in g_utf8_validate(): it's not a classic out
argument which gets allocated by the called function, but merely points into
one of its input arguments. Thus it is "transfer none".
https://bugzilla.gnome.org/show_bug.cgi?id=672889
* g_utf8_validate:
* @str: (array length=max_len) (element-type guint8): a pointer to character data
* @max_len: max bytes to validate, or -1 to go until NUL
- * @end: (allow-none) (out): return location for end of valid data
+ * @end: (allow-none) (out) (transfer none): return location for end of valid data
*
* Validates UTF-8 encoded text. @str is the text to validate;
* if @str is nul-terminated, then @max_len can be -1, otherwise