transaction: Only wait for ack from visible views

Transactions currently wait for all configures to be acked, regardless
fo what they were sent to. This includes views that are hidden in tabbed
or stacked containers. If these views do not ack the configure in
response to a single frame callback, they can cause transaction
timeouts.

Check if a container is hidden before registering the configure serial
and saving any view buffers.

Closes: https://github.com/swaywm/sway/issues/6023

sway/desktop/transaction.c

@@ -35,6 +35,7 @@ struct sway_transaction_instruction {
 		struct sway_container_state container_state;
 	};
 	uint32_t serial;
+	bool waiting;
 };
 
 static struct sway_transaction *transaction_create(void) {
@@ -420,13 +421,18 @@ static void transaction_commit(struct sway_transaction *transaction) {
 		struct sway_transaction_instruction *instruction =
 			transaction->instructions->items[i];
 		struct sway_node *node = instruction->node;
+		bool hidden = node_is_view(node) &&
+			!view_is_visible(node->sway_container->view);
 		if (should_configure(node, instruction)) {
 			instruction->serial = view_configure(node->sway_container->view,
 					instruction->container_state.content_x,
 					instruction->container_state.content_y,
 					instruction->container_state.content_width,
 					instruction->container_state.content_height);
-			++transaction->num_waiting;
+			if (!hidden) {
+				instruction->waiting = true;
+				++transaction->num_waiting;
+			}
 
 			// From here on we are rendering a saved buffer of the view, which
 			// means we can send a frame done event to make the client redraw it
@@ -437,7 +443,8 @@ static void transaction_commit(struct sway_transaction *transaction) {
 			wlr_surface_send_frame_done(
 					node->sway_container->view->surface, &now);
 		}
-		if (node_is_view(node) && wl_list_empty(&node->sway_container->view->saved_buffers)) {
+		if (!hidden && node_is_view(node) &&
+				wl_list_empty(&node->sway_container->view->saved_buffers)) {
 			view_save_buffer(node->sway_container->view);
 			memcpy(&node->sway_container->view->saved_geometry,
 					&node->sway_container->view->geometry,
@@ -490,7 +497,8 @@ static void set_instruction_ready(
 	}
 
 	// If the transaction has timed out then its num_waiting will be 0 already.
-	if (transaction->num_waiting > 0 && --transaction->num_waiting == 0) {
+	if (instruction->waiting && transaction->num_waiting > 0 &&
+			--transaction->num_waiting == 0) {
 		sway_log(SWAY_DEBUG, "Transaction %p is ready", transaction);
 		wl_event_source_timer_update(transaction->timer, 0);
 	}