Clean up Qt socket notifier to avoid spurious interrupt handler calls

chrisjbillington · chrisjbillington · commit 5685b8df8326 · 2025-06-24T14:27:21.000+10:00
Closes #29688 Objects without a parent are not necessarily cleaned up in PyQt when their reference count reaches zero, and must be explicitly cleaned up with `deleteLater()` This prevents the notifier firing after the signal handling was supposed to have been reset to its previous state.
diff --git a/lib/matplotlib/backend_bases.py b/lib/matplotlib/backend_bases.py
@@ -1655,6 +1655,7 @@ def save_args_and_handle_sigint(*args):
     finally:
         wsock.close()
         rsock.close()
+        notifier.deleteLater()
         signal.set_wakeup_fd(old_wakeup_fd)
         signal.signal(signal.SIGINT, old_sigint_handler)
         if handler_args is not None:
