Index: plug_import.c
===================================================================
--- plug_import.c	(revision 23703)
+++ plug_import.c	(revision 23704)
@@ -67,6 +67,9 @@
 		} \
 	} while(0)
 
+	if (f == NULL)
+		return NULL;
+
 	PCB_HOOK_CALL_ALL(pcb_plug_import_t, pcb_plug_import_chain, fmt_support_prio, cb_append,   (self, aspects, f, filename));
 	if (len == 0)
 		return NULL;