Clear the undefined position state when the window is placed

This allows the window to be recreated in the same location if needed, for example if recreated because of switching to OpenGL rendering.

src/events/SDL_windowevents.c

@@ -63,10 +63,8 @@ int SDL_SendWindowEvent(SDL_Window *window, SDL_EventType windowevent,
         window->flags |= SDL_WINDOW_HIDDEN;
         break;
     case SDL_EVENT_WINDOW_MOVED:
-        if (SDL_WINDOWPOS_ISUNDEFINED(data1) ||
-            SDL_WINDOWPOS_ISUNDEFINED(data2)) {
-            return 0;
-        }
+        window->undefined_x = SDL_FALSE;
+        window->undefined_y = SDL_FALSE;
         if (!(window->flags & SDL_WINDOW_FULLSCREEN)) {
             window->windowed.x = data1;
             window->windowed.y = data2;

src/video/windows/SDL_windowswindow.c

@@ -490,7 +490,6 @@ int WIN_CreateWindow(_THIS, SDL_Window *window)
     DWORD style = STYLE_BASIC;
     int x, y;
     int w, h;
-    SDL_bool undefined_position = SDL_FALSE;
 
     if (window->flags & SDL_WINDOW_SKIP_TASKBAR) {
         parent = CreateWindow(SDL_Appname, TEXT(""), STYLE_BASIC, 0, 0, 32, 32, NULL, NULL, SDL_Instance, NULL);
@@ -503,7 +502,6 @@ int WIN_CreateWindow(_THIS, SDL_Window *window)
 
     if (window->undefined_x && window->undefined_y &&
         window->last_displayID == SDL_GetPrimaryDisplay()) {
-        undefined_position = SDL_TRUE;
         x = CW_USEDEFAULT;
         y = CW_USEDEFAULT; /* Not actually used */
     }
@@ -523,12 +521,6 @@ int WIN_CreateWindow(_THIS, SDL_Window *window)
         return -1;
     }
 
-    if (undefined_position) {
-        /* Record where the window ended up */
-        window->windowed.x = window->x;
-        window->windowed.y = window->y;
-    }
-
     /* Inform Windows of the frame change so we can respond to WM_NCCALCSIZE */
     SetWindowPos(hwnd, NULL, 0, 0, 0, 0, SWP_FRAMECHANGED | SWP_NOSIZE | SWP_NOZORDER | SWP_NOMOVE | SWP_NOACTIVATE);
 

src/video/x11/SDL_x11window.c

@@ -644,12 +644,6 @@ int X11_CreateWindow(_THIS, SDL_Window *window)
     }
     windowdata = window->driverdata;
 
-    if (undefined_position) {
-        /* Record where the window ended up */
-        window->windowed.x = window->x;
-        window->windowed.y = window->y;
-    }
-
 #if SDL_VIDEO_OPENGL_ES || SDL_VIDEO_OPENGL_ES2 || SDL_VIDEO_OPENGL_EGL
     if ((window->flags & SDL_WINDOW_OPENGL) &&
         ((_this->gl_config.profile_mask == SDL_GL_CONTEXT_PROFILE_ES) ||