From c82c000bd413579237f5292d8076f045726efe15 Mon Sep 17 00:00:00 2001
From: "Devin J. Pohly" <djpohly@gmail.com>
Date: Sat, 11 Apr 2020 22:44:34 -0500
Subject: [PATCH] treat startup command as long-running

Not quite a perfect mirror of xinit, where the startup command execs the
window manager, and the termination of that process brings down the
windowing system, but it might be the Wayland analogue.
---
 dwl.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/dwl.c b/dwl.c
index 0ad6781..627f968 100644
--- a/dwl.c
+++ b/dwl.c
@@ -8,6 +8,8 @@
 #include <stdio.h>
 #include <time.h>
 #include <unistd.h>
+#include <sys/signal.h>
+#include <sys/wait.h>
 #include <linux/input-event-codes.h>
 #include <wayland-server-core.h>
 #include <wlr/backend.h>
@@ -865,6 +867,7 @@ static void server_new_xdg_surface(struct wl_listener *listener, void *data) {
 int main(int argc, char *argv[]) {
 	wlr_log_init(WLR_DEBUG, NULL);
 	char *startup_cmd = NULL;
+	pid_t startup_pid = -1;
 
 	int c;
 	while ((c = getopt(argc, argv, "s:h")) != -1) {
@@ -1002,8 +1005,17 @@ int main(int argc, char *argv[]) {
 	 * startup command if requested. */
 	setenv("WAYLAND_DISPLAY", socket, true);
 	if (startup_cmd) {
-		if (fork() == 0) {
+		startup_pid = fork();
+		if (startup_pid < 0) {
+			perror("startup: fork");
+			wl_display_destroy(server.wl_display);
+			return 1;
+		}
+		if (startup_pid == 0) {
 			execl("/bin/sh", "/bin/sh", "-c", startup_cmd, (void *)NULL);
+			perror("startup: execl");
+			wl_display_destroy(server.wl_display);
+			return 1;
 		}
 	}
 	/* Run the Wayland event loop. This does not return until you exit the
@@ -1014,6 +1026,11 @@ int main(int argc, char *argv[]) {
 			socket);
 	wl_display_run(server.wl_display);
 
+	if (startup_cmd) {
+		kill(startup_pid, SIGTERM);
+		waitpid(startup_pid, NULL, 0);
+	}
+
 	/* Once wl_display_run returns, we shut down the server. */
 	wl_display_destroy_clients(server.wl_display);
 	wl_display_destroy(server.wl_display);