bin/xbps-uunshare: allow relative chroot directory

bin/xbps-uunshare/main.c

@@ -157,7 +157,7 @@ main(int argc, char **argv)
 	if (argc < 2)
 		usage(argv0);
 
-	chrootdir = argv[0];
+	chrootdir = argv[-1];
 	cmd = argv[1];
 	cmdargs = argv + 1;
 
@@ -165,6 +165,14 @@ main(int argc, char **argv)
 	if (strcmp(chrootdir, "/") == 0)
 		die("/ is not allowed to be used as chrootdir");
 
+	/* Make chrootdir absolute */
+	if (chrootdir[0] != '/') {
+		char cwd[PATH_MAX-1];
+		if (getcwd(cwd, sizeof(cwd)) == NULL)
+			die("getcwd");
+		chrootdir = xbps_xasprintf("%s/%s", cwd, chrootdir);
+	}
+
 	/*
 	 * Unshare from the current process namespaces and set ours.
 	 */