From bb8537f657c4ef3e1b7958a82dbf768816b6ae5f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pa=CC=84vels=20Nadtoc=CC=8Cajevs?=
 <7645683+bruvzg@users.noreply.github.com>
Date: Fri, 28 Nov 2025 10:48:43 +0200
Subject: [PATCH] [Editor] Disable embedded mode, if `--headless` is in the
 main instance argument list.

---
 editor/run/game_view_plugin.cpp | 12 ++++++++++++
 editor/run/game_view_plugin.h   |  1 +
 2 files changed, 13 insertions(+)

diff --git a/editor/run/game_view_plugin.cpp b/editor/run/game_view_plugin.cpp
index 5361dbdd1d3..5b46a8b5547 100644
--- a/editor/run/game_view_plugin.cpp
+++ b/editor/run/game_view_plugin.cpp
@@ -44,6 +44,7 @@
 #include "editor/gui/window_wrapper.h"
 #include "editor/run/editor_run_bar.h"
 #include "editor/run/embedded_process.h"
+#include "editor/run/run_instances_dialog.h"
 #include "editor/settings/editor_feature_profile.h"
 #include "editor/settings/editor_settings.h"
 #include "editor/themes/editor_scale.h"
@@ -672,6 +673,14 @@ GameView::EmbedAvailability GameView::_get_embed_available() {
 		return EMBED_NOT_AVAILABLE_PROJECT_DISPLAY_DRIVER;
 	}
 
+	if (RunInstancesDialog::get_singleton()) {
+		List<String> instance_args;
+		RunInstancesDialog::get_singleton()->get_argument_list_for_instance(0, instance_args);
+		if (instance_args.find("--headless")) {
+			return EMBED_NOT_AVAILABLE_HEADLESS;
+		}
+	}
+
 	EditorRun::WindowPlacement placement = EditorRun::get_window_placement();
 	if (placement.force_fullscreen) {
 		return EMBED_NOT_AVAILABLE_FULLSCREEN;
@@ -731,6 +740,9 @@ void GameView::_update_ui() {
 		case EMBED_NOT_AVAILABLE_SINGLE_WINDOW_MODE:
 			state_label->set_text(TTRC("Game embedding not available in single window mode."));
 			break;
+		case EMBED_NOT_AVAILABLE_HEADLESS:
+			state_label->set_text(TTRC("Game embedding not available when the game starts in headless mode."));
+			break;
 	}
 
 	if (available == EMBED_AVAILABLE) {
diff --git a/editor/run/game_view_plugin.h b/editor/run/game_view_plugin.h
index 0876f809f73..cfb00f5ba21 100644
--- a/editor/run/game_view_plugin.h
+++ b/editor/run/game_view_plugin.h
@@ -129,6 +129,7 @@ class GameView : public VBoxContainer {
 		EMBED_NOT_AVAILABLE_FULLSCREEN,
 		EMBED_NOT_AVAILABLE_SINGLE_WINDOW_MODE,
 		EMBED_NOT_AVAILABLE_PROJECT_DISPLAY_DRIVER,
+		EMBED_NOT_AVAILABLE_HEADLESS,
 	};
 
 	inline static GameView *singleton = nullptr;