macOS: fix panic during drag_window

Return error from it instead of unwrapping.

src/changelog/unreleased.md

@@ -186,6 +186,7 @@ changelog entry.
 
 - On Orbital, `MonitorHandle::name()` now returns `None` instead of a dummy name.
 - On macOS, fix `WindowEvent::Moved` sometimes being triggered unnecessarily on resize.
-- On MacOS, package manifest definitions of `LSUIElement` will no longer be overridden with the
+- On macOS, package manifest definitions of `LSUIElement` will no longer be overridden with the
   default activation policy, unless explicitly provided during initialization.
+- On macOS, fix crash when calling `drag_window()` without a left click present.
 - On X11, key events forward to IME anyway, even when it's disabled.

src/platform_impl/apple/appkit/window.rs

@@ -284,8 +284,7 @@ impl CoreWindow for Window {
     }
 
     fn drag_window(&self) -> Result<(), RequestError> {
-        self.maybe_wait_on_main(|delegate| delegate.drag_window());
-        Ok(())
+        self.maybe_wait_on_main(|delegate| delegate.drag_window())
     }
 
     fn drag_resize_window(

src/platform_impl/apple/appkit/window_delegate.rs

@@ -1171,10 +1171,12 @@ impl WindowDelegate {
     }
 
     #[inline]
-    pub fn drag_window(&self) {
+    pub fn drag_window(&self) -> Result<(), RequestError> {
         let mtm = MainThreadMarker::from(self);
-        let event = NSApplication::sharedApplication(mtm).currentEvent().unwrap();
+        let event =
+            NSApplication::sharedApplication(mtm).currentEvent().ok_or(RequestError::Ignored)?;
         self.window().performWindowDragWithEvent(&event);
+        Ok(())
     }
 
     #[inline]