Always imply iso shutdown in fw_destroy_handle

because ieee1394_destroy_handle does it too.  Otherwise, clients which
rely on the ieee1394 backend behaviour leak memory when running on the
juju backend.

Also add the ability to call fw_iso_shutdown multiple times or before
a successful context initialization.  Faulty clients might rely on it
based on ieee1394 backend behaviour.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

src/fw-iso.c

@@ -602,6 +602,9 @@ void fw_iso_stop(fw_handle_t handle)
 
 void fw_iso_shutdown(fw_handle_t handle)
 {
+	if (handle->iso.packets == NULL)
+		return;
+
 	munmap(handle->iso.buffer,
 	       handle->iso.buf_packets * handle->iso.max_packet_size);
 	if (handle->iso.state != ISO_STOPPED)

src/fw.c

@@ -502,9 +502,8 @@ void fw_destroy_handle(fw_handle_t handle)
 
 		close(handle->devices[i].fd);
 	}
-
+	fw_iso_shutdown(handle);
 	close(handle->epoll_fd);
-
 	free(handle);
 
 	return;