SDL: Fix windows created with SDL_WINDOW_MINIMIZED having inconsistent SDL_WINDOW_HIDDEN flag on Windows

From 565e95ac4e4cd76e4b24afbbabf5054c85377438 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Thu, 6 Jul 2023 18:14:27 -0700
Subject: [PATCH] Fix windows created with SDL_WINDOW_MINIMIZED having
 inconsistent SDL_WINDOW_HIDDEN flag on Windows

- Windows created minimized are shown with SW_SHOWMINNOACTIVE which does not send WM_SHOWWINDOW leaving the window visible (but minimized)
  on desktop but still with the SDL_WINDOW_HIDDEN flag set. Now the hidden flag is cleared in this case but noted that this means it's not currently possible
  to create a window that is initially hidden that then is minimized once shown.
---
 src/video/windows/SDL_windowswindow.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/video/windows/SDL_windowswindow.c b/src/video/windows/SDL_windowswindow.c
index c200359e4f05..bdd3d92a2a92 100644
--- a/src/video/windows/SDL_windowswindow.c
+++ b/src/video/windows/SDL_windowswindow.c
@@ -567,6 +567,11 @@ int WIN_CreateWindow(SDL_VideoDevice *_this, SDL_Window *window)
     SetWindowPos(hwnd, NULL, 0, 0, 0, 0, SWP_FRAMECHANGED | SWP_NOSIZE | SWP_NOMOVE | SWP_NOZORDER | SWP_NOOWNERZORDER | SWP_NOACTIVATE);
 
     if (window->flags & SDL_WINDOW_MINIMIZED) {
+        /* TODO: We have to clear SDL_WINDOW_HIDDEN here to ensure the window flags match the window state. The
+           window is already shown after this and windows with WS_MINIMIZE do not generate a WM_SHOWWINDOW. This
+           means you can't currently create a window that is initially hidden and is minimized when shown.
+        */
+        window->flags &= ~SDL_WINDOW_HIDDEN;
         ShowWindow(hwnd, SW_SHOWMINNOACTIVE);
     }