From 55138dbe0eefb37a052036500406e45423e3639a Mon Sep 17 00:00:00 2001
From: Consolatis <35009135+Consolatis@users.noreply.github.com>
Date: Sat, 13 Apr 2024 10:01:30 +0200
Subject: [PATCH] server: don't create headless backend twice

This may happen when running with WLR_BACKENDS=headless.

Fixes: #1618
---
 src/server.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/server.c b/src/server.c
index ceac9cec..4210f069 100644
--- a/src/server.c
+++ b/src/server.c
@@ -278,6 +278,15 @@ static const char helpful_seat_error_message[] =
 "If the above does not work, try running with `WLR_RENDERER=pixman labwc` in\n"
 "order to use the software rendering fallback\n";
 
+static void
+get_headless_backend(struct wlr_backend *backend, void *data)
+{
+	if (wlr_backend_is_headless(backend)) {
+		struct wlr_backend **headless = data;
+		*headless = backend;
+	}
+}
+
 void
 server_init(struct server *server)
 {
@@ -327,7 +336,16 @@ server_init(struct server *server)
 	}
 
 	/* Create headless backend to enable adding virtual outputs later on */
-	server->headless.backend = wlr_headless_backend_create(server->wl_display);
+	wlr_multi_for_each_backend(server->backend,
+		get_headless_backend, &server->headless.backend);
+
+	if (!server->headless.backend) {
+		wlr_log(WLR_DEBUG, "manually creating headless backend");
+		server->headless.backend = wlr_headless_backend_create(server->wl_display);
+	} else {
+		wlr_log(WLR_DEBUG, "headless backend already exists");
+	}
+
 	if (!server->headless.backend) {
 		wlr_log(WLR_ERROR, "unable to create headless backend");
 		exit(EXIT_FAILURE);
-- 
2.52.0