Clean up stale detached gamepads before hotplug reattach

app/streaming/input/gamepad.cpp

@@ -63,6 +63,25 @@ SdlInputHandler::findStateForGamepad(SDL_JoystickID id)
     return nullptr;
 }
 
+void SdlInputHandler::cleanupDetachedGamepads()
+{
+    for (int i = 0; i < MAX_GAMEPADS; i++) {
+        if (m_GamepadState[i].controller == nullptr ||
+                SDL_GameControllerGetAttached(m_GamepadState[i].controller)) {
+            continue;
+        }
+
+        SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION,
+                    "Found detached gamepad in slot %d without removal event; cleaning up",
+                    i);
+
+        SDL_ControllerDeviceEvent controllerEvent = {};
+        controllerEvent.type = SDL_CONTROLLERDEVICEREMOVED;
+        controllerEvent.which = m_GamepadState[i].jsId;
+        handleControllerDeviceEvent(&controllerEvent);
+    }
+}
+
 void SdlInputHandler::sendGamepadState(GamepadState* state)
 {
     SDL_assert(m_GamepadMask == 0x1 || m_MultiController);
@@ -582,6 +601,8 @@ void SdlInputHandler::handleControllerDeviceEvent(SDL_ControllerDeviceEvent* eve
     GamepadState* state;
 
     if (event->type == SDL_CONTROLLERDEVICEADDED) {
+        cleanupDetachedGamepads();
+
         int i;
         const char* name;
         SDL_GameController* controller;

app/streaming/input/input.h

@@ -185,6 +185,8 @@ private:
     GamepadState*
     findStateForGamepad(SDL_JoystickID id);
 
+    void cleanupDetachedGamepads();
+
     void sendGamepadState(GamepadState* state);
 
     void sendGamepadBatteryState(GamepadState* state, SDL_JoystickPowerLevel level);