Windows: fix window resizing with decorations disabled

src/changelog/unreleased.md

@@ -245,3 +245,4 @@ changelog entry.
 - On macos, `WindowExtMacOS::set_simple_fullscreen` now honors `WindowExtMacOS::set_borderless_game`
 - On X11 and Wayland, fixed pump_events with `Some(Duration::Zero)` blocking with `Wait` polling mode
 - On macOS, fixed `run_app_on_demand` returning without closing open windows.
+- On Windows, fixed window resizing with decorated shadow disabled.

src/platform_impl/windows/event_loop.rs

@@ -1096,7 +1096,9 @@ unsafe fn public_window_callback_inner(
                 if let Ok(monitor_info) = monitor::get_monitor_info(monitor) {
                     params.rgrc[0] = monitor_info.monitorInfo.rcWork;
                 }
-            } else if window_flags.contains(WindowFlags::MARKER_UNDECORATED_SHADOW) {
+            } else if !window_flags.contains(WindowFlags::MARKER_DECORATIONS)
+                || window_flags.contains(WindowFlags::MARKER_UNDECORATED_SHADOW)
+            {
                 // Extend the client area to cover the whole non-client area.
                 // https://docs.microsoft.com/en-us/windows/win32/winmsg/wm-nccalcsize#remarks
                 //
@@ -1109,7 +1111,9 @@ unsafe fn public_window_callback_inner(
                 // ahead of the window surface. Currently, there seems no option to achieve this
                 // with the Windows API.
                 params.rgrc[0].top += 1;
-                params.rgrc[0].bottom += 1;
+                params.rgrc[0].bottom -= 9;
+                params.rgrc[0].left += 9;
+                params.rgrc[0].right -= 9;
             }
 
             result = ProcResult::Value(0);