fix: keep the headless daemon running

main.c

@@ -10,7 +10,8 @@ char *fontdir;
 int
 threadmaybackground(void)
 {
-	return 1;
+	/* Keep the launcher PID stable so supervisors can own this daemon. */
+	return 0;
 }
 
 void
@@ -57,6 +58,9 @@ erealloc(void *p, ulong n)
 void
 threadmain(int argc, char **argv)
 {
+	Channel *waitc;
+	uchar stop;
+
 	if(argc != 3)
 		usage();
 
@@ -80,5 +84,7 @@ threadmain(int argc, char **argv)
 	if(threadcreate(imthread, nil, 16384) < 0)
 		die("can't create input worker");
 
-	threadexits(nil);
+	/* Keep the supervising process and its externally visible PID alive. */
+	waitc = chancreate(sizeof stop, 0);
+	chanrecv(waitc, &stop);
 }