video: Add a "VideoPreQuit" method, move Windows hotplug shutdown to it.

src/video/SDL_sysvideo.h

@@ -225,6 +225,15 @@ struct SDL_VideoDevice
      */
     bool (*VideoInit)(SDL_VideoDevice *_this);
 
+    /*
+     * Called when Video subsystem is beginning to terminate. This allows for
+     * special case code that need to happen before internal SDL bits
+     * clean up that must happen before VideoQuit(). An example is stopping
+     * a hotplug thread that might add mice/keyboards after SDL has cleaned
+     * up its internal list. Most work is meant to happen in VideoQuit, though.
+     */
+    void (*VideoPreQuit)(SDL_VideoDevice *_this);
+
     /*
      * Reverse the effects VideoInit() -- called if VideoInit() fails or
      * if the application is shutting down the video subsystem.

src/video/SDL_video.c

@@ -4718,6 +4718,10 @@ void SDL_QuitVideo(void)
 
     _this->is_quitting = true;
 
+    if (_this->VideoPreQuit) {
+        _this->VideoPreQuit(_this);
+    }
+
     // Halt event processing before doing anything else
 #if 0 // This was moved to the end to fix a memory leak
     SDL_QuitPen();

src/video/windows/SDL_windowsvideo.c

@@ -136,6 +136,7 @@ struct ITaskbarList3
 // Initialization/Query functions
 static bool WIN_VideoInit(SDL_VideoDevice *_this);
 static void WIN_VideoQuit(SDL_VideoDevice *_this);
+static void WIN_VideoPreQuit(SDL_VideoDevice *_this);
 
 // Hints
 bool g_WindowsEnableMessageLoop = true;
@@ -327,6 +328,7 @@ static SDL_VideoDevice *WIN_CreateDevice(void)
 
     // Set the function pointers
     device->VideoInit = WIN_VideoInit;
+    device->VideoPreQuit = WIN_VideoPreQuit;
     device->VideoQuit = WIN_VideoQuit;
 #if !defined(SDL_PLATFORM_XBOXONE) && !defined(SDL_PLATFORM_XBOXSERIES)
     device->RefreshDisplays = WIN_RefreshDisplays;
@@ -669,6 +671,13 @@ static bool WIN_VideoInit(SDL_VideoDevice *_this)
     return true;
 }
 
+void WIN_VideoPreQuit(SDL_VideoDevice *_this)
+{
+#if !defined(SDL_PLATFORM_XBOXONE) && !defined(SDL_PLATFORM_XBOXSERIES)
+    WIN_QuitDeviceNotification();  // stop hotplug thread before the rest of the video subsystem cleans up.
+#endif
+}
+
 void WIN_VideoQuit(SDL_VideoDevice *_this)
 {
     SDL_VideoData *data = _this->internal;
@@ -685,7 +694,6 @@ void WIN_VideoQuit(SDL_VideoDevice *_this)
 
 #if !defined(SDL_PLATFORM_XBOXONE) && !defined(SDL_PLATFORM_XBOXSERIES)
     WIN_QuitModes(_this);
-    WIN_QuitDeviceNotification();
     WIN_QuitKeyboard(_this);
     WIN_QuitMouse(_this);