Make sure not to discard data on partitioning or unregistration

src/datawizard/filters.c

@@ -570,7 +570,7 @@ void starpu_data_partition(starpu_data_handle_t initial_handle, struct starpu_da
 	initial_handle->children = NULL;
 
 	/* Make sure to wait for previous tasks working on the whole data */
-	starpu_data_acquire_on_node(initial_handle, STARPU_ACQUIRE_NO_NODE, STARPU_W);
+	starpu_data_acquire_on_node(initial_handle, STARPU_ACQUIRE_NO_NODE, initial_handle->initialized?STARPU_RW:STARPU_W);
 	starpu_data_release_on_node(initial_handle, STARPU_ACQUIRE_NO_NODE);
 
 	_starpu_data_partition(initial_handle, NULL, nparts, f, 1);

src/datawizard/interfaces/data_interface.c

@@ -960,7 +960,7 @@ void starpu_data_unregister_submit(starpu_data_handle_t handle)
 	}
 
 	/* Wait for all task dependencies on this handle before putting it for free */
-	starpu_data_acquire_on_node_cb(handle, STARPU_ACQUIRE_NO_NODE_LOCK_ALL, STARPU_W, _starpu_data_unregister_submit_cb, handle);
+	starpu_data_acquire_on_node_cb(handle, STARPU_ACQUIRE_NO_NODE_LOCK_ALL, handle->initialized?STARPU_RW:STARPU_W, _starpu_data_unregister_submit_cb, handle);
 }
 
 static void _starpu_data_invalidate(void *data)