From 62fa80afd7734c40aef4148d71a43cd6c52e26ab Mon Sep 17 00:00:00 2001
From: Markus Sauermann <6299227+Sauermann@users.noreply.github.com>
Date: Sun, 13 Mar 2022 23:54:13 +0100
Subject: [PATCH] Cleanup internal GUI state, if event is accepted in _input.

---
 scene/main/viewport.cpp | 13 +++++++++++++
 scene/main/viewport.h   |  1 +
 2 files changed, 14 insertions(+)

diff --git a/scene/main/viewport.cpp b/scene/main/viewport.cpp
index 25c3ced3da6..1c1a479b0bd 100644
--- a/scene/main/viewport.cpp
+++ b/scene/main/viewport.cpp
@@ -2496,6 +2496,17 @@ void Viewport::_gui_input_event(Ref<InputEvent> p_event) {
 	}
 }
 
+void Viewport::_gui_cleanup_internal_state(Ref<InputEvent> p_event) {
+	ERR_FAIL_COND(p_event.is_null());
+
+	Ref<InputEventMouseButton> mb = p_event;
+	if (mb.is_valid()) {
+		if (!mb->is_pressed()) {
+			gui.mouse_focus_mask &= ~(1 << (mb->get_button_index() - 1)); // Remove from mask.
+		}
+	}
+}
+
 List<Control *>::Element *Viewport::_gui_add_root_control(Control *p_control) {
 	gui.roots_order_dirty = true;
 	return gui.roots.push_back(p_control);
@@ -2851,6 +2862,8 @@ void Viewport::input(const Ref<InputEvent> &p_event) {
 
 	if (!is_input_handled()) {
 		_gui_input_event(p_event);
+	} else {
+		_gui_cleanup_internal_state(p_event);
 	}
 	//get_tree()->call_group(SceneTree::GROUP_CALL_REVERSE|SceneTree::GROUP_CALL_REALTIME|SceneTree::GROUP_CALL_MULIILEVEL,gui_input_group,"_gui_input",p_event); //special one for GUI, as controls use their own process check
 }
diff --git a/scene/main/viewport.h b/scene/main/viewport.h
index c7ef4834d83..a4d22805981 100644
--- a/scene/main/viewport.h
+++ b/scene/main/viewport.h
@@ -340,6 +340,7 @@ private:
 	Control *_gui_find_control_at_pos(CanvasItem *p_node, const Point2 &p_global, const Transform2D &p_xform, Transform2D &r_inv_xform);
 
 	void _gui_input_event(Ref<InputEvent> p_event);
+	void _gui_cleanup_internal_state(Ref<InputEvent> p_event);
 
 	void update_worlds();