fix cursor blinking when clicking decorations bar on Windows (#1852)

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Unreleased
 
 - Added `is_maximized` method to `Window`.
+- On Windows, fix bug where clicking the decoration bar would make the cursor blink.
 - On Windows, fix bug causing newly created windows to erroneously display the "wait" (spinning) cursor.
 - On Windows, change the default window size (1024x768) to match the default on other desktop platforms (800x600).
 - On Windows, fix bug causing mouse capture to not be released.

src/platform_impl/windows/event_loop.rs

@@ -845,7 +845,7 @@ unsafe fn public_window_callback_inner<T: 'static>(
         }
         winuser::WM_NCLBUTTONDOWN => {
             if wparam == winuser::HTCAPTION as _ {
-                winuser::PostMessageW(window, winuser::WM_MOUSEMOVE, 0, 0);
+                winuser::PostMessageW(window, winuser::WM_MOUSEMOVE, 0, lparam);
             }
             commctrl::DefSubclassProc(window, msg, wparam, lparam)
         }