* and only if it has textconv enabled (otherwise return NULL). The result
* can be passed to fill_textconv().
*/
-struct userdiff_driver *get_textconv(struct diff_filespec *one);
+struct userdiff_driver *get_textconv(struct index_state *istate,
+ struct diff_filespec *one);
/*
* Prepare diff_filespec and convert it using diff textconv API