From dacd5a9e3db7d9393017b24050e0385d7ec699d2 Mon Sep 17 00:00:00 2001
From: Cameron Gutman <aicommander@gmail.com>
Date: Mon, 17 Jan 2022 19:49:52 -0600
Subject: [PATCH] Discard stale gamepad events when enabling gamepad navigation

---
 app/gui/sdlgamepadkeynavigation.cpp | 14 ++++++++++++++
 app/gui/sdlgamepadkeynavigation.h   |  1 +
 2 files changed, 15 insertions(+)

diff --git a/app/gui/sdlgamepadkeynavigation.cpp b/app/gui/sdlgamepadkeynavigation.cpp
index 4e9f1952..ff978d9f 100644
--- a/app/gui/sdlgamepadkeynavigation.cpp
+++ b/app/gui/sdlgamepadkeynavigation.cpp
@@ -12,6 +12,7 @@
 SdlGamepadKeyNavigation::SdlGamepadKeyNavigation()
     : m_Enabled(false),
       m_UiNavMode(false),
+      m_FirstPoll(false),
       m_LastAxisNavigationEventTime(0)
 {
     m_PollingTimer = new QTimer(this);
@@ -62,6 +63,9 @@ void SdlGamepadKeyNavigation::enable()
         }
     }
 
+    // Flush events on the first poll
+    m_FirstPoll = true;
+
     // Poll every 50 ms for a new joystick event
     m_PollingTimer->start(50);
 
@@ -91,6 +95,16 @@ void SdlGamepadKeyNavigation::onPollingTimerFired()
     SDL_Event event;
     StreamingPreferences prefs;
 
+    // Discard any pending button events on the first poll to avoid picking up
+    // stale input data from the stream session (like the quit combo).
+    if (m_FirstPoll) {
+        SDL_PumpEvents();
+        SDL_FlushEvent(SDL_CONTROLLERBUTTONDOWN);
+        SDL_FlushEvent(SDL_CONTROLLERBUTTONUP);
+
+        m_FirstPoll = false;
+    }
+
     while (SDL_PollEvent(&event)) {
         switch (event.type) {
         case SDL_QUIT:
diff --git a/app/gui/sdlgamepadkeynavigation.h b/app/gui/sdlgamepadkeynavigation.h
index bdec990d..f4e54a95 100644
--- a/app/gui/sdlgamepadkeynavigation.h
+++ b/app/gui/sdlgamepadkeynavigation.h
@@ -34,5 +34,6 @@ private:
     QList<SDL_GameController*> m_Gamepads;
     bool m_Enabled;
     bool m_UiNavMode;
+    bool m_FirstPoll;
     Uint32 m_LastAxisNavigationEventTime;
 };