context: Make it clear why we copy the ids

Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>

src/context.c

@@ -96,12 +96,19 @@ VAStatus SunxiCedrusCreateContext(VADriverContextP context,
 		goto error;
 	}
 
+	/*
+	 * The surface_ids array has been allocated by the caller and
+	 * we don't have any indication wrt its life time. Let's make sure
+	 * its life span is under our control.
+	 */
 	ids = malloc(surfaces_count * sizeof(VASurfaceID));
 	if (ids == NULL) {
 		status = VA_STATUS_ERROR_ALLOCATION_FAILED;
 		goto error;
 	}
 
+	memcpy(ids, surfaces_ids, surfaces_count * sizeof(VASurfaceID));
+
 	for (i = 0; i < surfaces_count; i++) {
 		surface_object = SURFACE(surfaces_ids[i]);
 		if (surface_object == NULL) {
@@ -125,8 +132,6 @@ VAStatus SunxiCedrusCreateContext(VADriverContextP context,
 		surface_object->destination_index = i;
 		surface_object->source_data = source_data;
 		surface_object->source_size = length;
-
-		ids[i] = surfaces_ids[i];
 	}
 
 	rc = v4l2_set_stream(driver_data->video_fd, V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE, true);