SDL: Correct the maximized size and position for borderless resizable windows

From 41e1a2360f2b26d9167b85f2f2259757d4f5ea28 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Tue, 27 Jul 2021 16:50:06 -0700
Subject: [PATCH] Correct the maximized size and position for borderless
 resizable windows

This fixes bug https://github.com/libsdl-org/SDL/issues/4043
---
 src/video/windows/SDL_windowsevents.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/video/windows/SDL_windowsevents.c b/src/video/windows/SDL_windowsevents.c
index 01fd369b36..1481b03144 100644
--- a/src/video/windows/SDL_windowsevents.c
+++ b/src/video/windows/SDL_windowsevents.c
@@ -963,6 +963,14 @@ WIN_WindowProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
             /* Fix our size to the current size */
             info = (MINMAXINFO *) lParam;
             if (SDL_GetWindowFlags(data->window) & SDL_WINDOW_RESIZABLE) {
+                if (SDL_GetWindowFlags(data->window) & SDL_WINDOW_BORDERLESS) {
+                    int screenW = GetSystemMetrics(SM_CXSCREEN);
+                    int screenH = GetSystemMetrics(SM_CYSCREEN);
+                    info->ptMaxSize.x = SDL_max(w, screenW);
+                    info->ptMaxSize.y = SDL_max(h, screenH);
+                    info->ptMaxPosition.x = SDL_min(0, ((screenW - w) / 2));
+                    info->ptMaxPosition.y = SDL_min(0, ((screenH - h) / 2));
+                }
                 info->ptMinTrackSize.x = w + min_w;
                 info->ptMinTrackSize.y = h + min_h;
                 if (constrain_max_size) {