fix: ensure --with-cursor, and with_cursor argument & attribute, are simple NOOP on platforms not supporting the feature

Author: BoboTiG

CHANGELOG

@@ -3,6 +3,7 @@ History:
 <see Git checking messages for history>
 
 8.0.1   2023/xx/xx
+      - MSS: ensure --with-cursor, and with_cursor argument & attribute, are simple NOOP on platforms not supporting the feature
       - CLI: do not raise a ScreenShotError when -q, or --quiet, is used but return 1
       - tests: fix test_entry_point() with multiple monitors having the same resolution
 

mss/base.py

@@ -88,9 +88,8 @@ def grab(self, monitor: Union[Monitor, Tuple[int, int, int, int]], /) -> ScreenS
 
         with lock:
             screenshot = self._grab_impl(monitor)
-            if self.with_cursor:
-                cursor = self._cursor_impl()
-                screenshot = self._merge(screenshot, cursor)  # type: ignore[arg-type]
+            if self.with_cursor and (cursor := self._cursor_impl()):
+                return self._merge(screenshot, cursor)
             return screenshot
 
     @property