From 17d7e6a142500a80ba6628a32eca792c44bbbdb7 Mon Sep 17 00:00:00 2001
From: Fabio Alessandrelli <fabio.alessandrelli@gmail.com>
Date: Mon, 17 Oct 2016 03:57:32 +0200
Subject: [PATCH] Fix Keyboard Input Hangs when using modifiers

Main input parsing loop only update actions for keyboard if the state has changed.
`InputMap::event_is_action` now ignores keyboard modifiers if the event is not pressed.
Clarify difference between `InputMap::action_has_event` and `InputMap::event_is_action` in docs.

Fixes #6388.
---
 core/input_map.cpp     |  6 +++---
 core/input_map.h       |  2 +-
 doc/base/classes.xml   |  2 +-
 main/input_default.cpp | 14 +++++++-------
 4 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/core/input_map.cpp b/core/input_map.cpp
index 09cb7ce426e..ad1403a64be 100644
--- a/core/input_map.cpp
+++ b/core/input_map.cpp
@@ -106,7 +106,7 @@ List<StringName> InputMap::get_actions() const {
 	return actions;
 }
 
-List<InputEvent>::Element *InputMap::_find_event(List<InputEvent> &p_list,const InputEvent& p_event) const {
+List<InputEvent>::Element *InputMap::_find_event(List<InputEvent> &p_list,const InputEvent& p_event, bool p_mod_ignore=false) const {
 
 	for (List<InputEvent>::Element *E=p_list.front();E;E=E->next()) {
 
@@ -122,7 +122,7 @@ List<InputEvent>::Element *InputMap::_find_event(List<InputEvent> &p_list,const
 
 			case InputEvent::KEY: {
 
-				same=(e.key.scancode==p_event.key.scancode && e.key.mod == p_event.key.mod);
+				same=(e.key.scancode==p_event.key.scancode && (p_mod_ignore || e.key.mod == p_event.key.mod));
 
 			} break;
 			case InputEvent::JOYSTICK_BUTTON: {
@@ -229,7 +229,7 @@ bool InputMap::event_is_action(const InputEvent& p_event, const StringName& p_ac
 		return p_event.action.action==E->get().id;
 	}
 
-	return _find_event(E->get().inputs,p_event)!=NULL;
+	return _find_event(E->get().inputs,p_event,!p_event.is_pressed())!=NULL;
 }
 
 const Map<StringName, InputMap::Action>& InputMap::get_action_map() const {
diff --git a/core/input_map.h b/core/input_map.h
index 21c479588d1..a974f6f1036 100644
--- a/core/input_map.h
+++ b/core/input_map.h
@@ -46,7 +46,7 @@ private:
 	mutable Map<StringName, Action> input_map;
 	mutable Map<int,StringName> input_id_map;
 
-	List<InputEvent>::Element *_find_event(List<InputEvent> &p_list,const InputEvent& p_event) const;
+	List<InputEvent>::Element *_find_event(List<InputEvent> &p_list,const InputEvent& p_event, bool p_mod_ignore) const;
 
 	Array _get_action_list(const StringName& p_action);
 	Array _get_actions();
diff --git a/doc/base/classes.xml b/doc/base/classes.xml
index 4e0ba53f482..a711f591c66 100644
--- a/doc/base/classes.xml
+++ b/doc/base/classes.xml
@@ -18019,7 +18019,7 @@
 			<argument index="1" name="action" type="String">
 			</argument>
 			<description>
-				Return whether the given event is part of an existing action.
+				Return whether the given event is part of an existing action. This method ignores keyboard modifiers if the given [InputEvent] is not pressed (for proper release detection). See [method action_has_event] if you don't want this behavior.
 			</description>
 		</method>
 		<method name="get_action_from_id" qualifiers="const">
diff --git a/main/input_default.cpp b/main/input_default.cpp
index c60fcd22434..6c2c6ebbb3a 100644
--- a/main/input_default.cpp
+++ b/main/input_default.cpp
@@ -377,13 +377,13 @@ void InputDefault::parse_input_event(const InputEvent& p_event) {
 
 			if (InputMap::get_singleton()->event_is_action(p_event,E->key())) {
 
-				Action action;
-				action.fixed_frame=OS::get_singleton()->get_fixed_frames();
-				action.idle_frame=OS::get_singleton()->get_idle_frames();
-				action.pressed=p_event.is_pressed();
-
-				action_state[E->key()]=action;
-
+				if(is_action_pressed(E->key()) != p_event.is_pressed()) {
+					Action action;
+					action.fixed_frame=OS::get_singleton()->get_fixed_frames();
+					action.idle_frame=OS::get_singleton()->get_idle_frames();
+					action.pressed=p_event.is_pressed();
+					action_state[E->key()]=action;
+				}
 			}
 		}
 	}