On Windows, apply ScaleFactorChanged new size if different than OS (#…

…3408)

This fixes an issue when setting the position of the window on a new monitor and immediately maximizing it

```rs
window.set_outer_position::<PhysicalPosition<u32>>((2000, 200).into());
window.set_maximized(true);
```

Due to the nature of the event loop, the requested position and maximization state will apply correctly but due to the fact that the new position is a different monitor, a `ScaleFactorChanged` is emitted afterwards to the evenloop and a new size is set while the window is still maximized which results in a window that has `WS_MAXIMZE` window style but doesn't cover the whole monitor.

CHANGELOG.md

@@ -47,6 +47,7 @@ Unreleased` header.
 - On X11, fix deadlock when adjusting DPI and resizing at the same time.
 - On Wayland, fix `Focused(false)` being send when other seats still have window focused.
 - On Wayland, fix `Window::set_{min,max}_inner_size` not always applied.
+- On Windows, fix inconsistent resizing behavior with multi-monitor setups when repositioning outside the event loop.
 
 # 0.29.10
 

src/platform_impl/windows/event_loop/runner.rs

@@ -399,23 +399,29 @@ impl<T> BufferedEvent<T> {
         match self {
             Self::Event(event) => dispatch(event),
             Self::ScaleFactorChanged(window_id, scale_factor, new_inner_size) => {
-                let new_inner_size = Arc::new(Mutex::new(new_inner_size));
+                let user_new_innner_size = Arc::new(Mutex::new(new_inner_size));
                 dispatch(Event::WindowEvent {
                     window_id,
                     event: WindowEvent::ScaleFactorChanged {
                         scale_factor,
-                        inner_size_writer: InnerSizeWriter::new(Arc::downgrade(&new_inner_size)),
+                        inner_size_writer: InnerSizeWriter::new(Arc::downgrade(
+                            &user_new_innner_size,
+                        )),
                     },
                 });
-                let inner_size = *new_inner_size.lock().unwrap();
-                drop(new_inner_size);
-
-                let window_flags = unsafe {
-                    let userdata =
-                        get_window_long(window_id.0.into(), GWL_USERDATA) as *mut WindowData;
-                    (*userdata).window_state_lock().window_flags
-                };
-                window_flags.set_size((window_id.0).0, inner_size);
+                let inner_size = *user_new_innner_size.lock().unwrap();
+
+                drop(user_new_innner_size);
+
+                if inner_size != new_inner_size {
+                    let window_flags = unsafe {
+                        let userdata =
+                            get_window_long(window_id.0.into(), GWL_USERDATA) as *mut WindowData;
+                        (*userdata).window_state_lock().window_flags
+                    };
+
+                    window_flags.set_size((window_id.0).0, inner_size);
+                }
             }
         }
     }