clients: Check return value of wl_display_dispatch()

The simple clients all just call wl_display_dispatch() in a while loop
without checking the return value.  Now, if the server dies or other
error occurs, we get a -1 return value instead and need to break the loop.

clients/simple-egl.c

@@ -591,7 +591,7 @@ main(int argc, char **argv)
 	struct sigaction sigint;
 	struct display display = { 0 };
 	struct window  window  = { 0 };
-	int i;
+	int i, ret = 0;
 
 	window.display = &display;
 	display.window = &window;
@@ -627,8 +627,8 @@ main(int argc, char **argv)
 	sigint.sa_flags = SA_RESETHAND;
 	sigaction(SIGINT, &sigint, NULL);
 
-	while (running)
-		wl_display_dispatch(display.display);
+	while (running && ret != -1)
+		ret = wl_display_dispatch(display.display);
 
 	fprintf(stderr, "simple-egl exiting\n");
 

clients/simple-shm.c

@@ -328,6 +328,7 @@ main(int argc, char **argv)
 	struct sigaction sigint;
 	struct display *display;
 	struct window *window;
+	int ret;
 
 	display = create_display();
 	window = create_window(display, 250, 250);
@@ -344,8 +345,8 @@ main(int argc, char **argv)
 
 	redraw(window, NULL, 0);
 
-	while (running)
-		wl_display_dispatch(display->display);
+	while (running && ret != -1)
+		ret = wl_display_dispatch(display->display);
 
 	fprintf(stderr, "simple-shm exiting\n");
 	destroy_window(window);

clients/simple-touch.c

@@ -316,11 +316,12 @@ int
 main(int argc, char **argv)
 {
 	struct touch *touch;
+	int ret = 0;
 
 	touch = touch_create(600, 500);
 
-	while (true)
-		wl_display_dispatch(touch->display);
+	while (ret != -1)
+		ret = wl_display_dispatch(touch->display);
 
 	return 0;
 }

clients/window.c

@@ -3837,8 +3837,13 @@ handle_display_data(struct task *task, uint32_t events)
 		return;
 	}
 
-	if (events & EPOLLIN)
-		wl_display_dispatch(display->display);
+	if (events & EPOLLIN) {
+		ret = wl_display_dispatch(display->display);
+		if (ret == -1) {
+			display_exit(display);
+			return;
+		}
+	}
 
 	if (events & EPOLLOUT) {
 		ret = wl_display_flush(display->display);