macos: fix a crash when InputCapture is dropped (#323)

Author: feschber

input-capture/src/macos.rs

@@ -390,9 +390,9 @@ fn create_event_tap<'a>(
 
             if let Some(pos) = pos {
                 res_events.iter().for_each(|e| {
-                    event_tx
-                        .blocking_send((pos, *e))
-                        .expect("Failed to send event");
+                    // error must be ignored, since the event channel
+                    // may already be closed when the InputCapture instance is dropped.
+                    let _ = event_tx.blocking_send((pos, *e));
                 });
                 // Returning None should stop the event from being processed
                 // but core fundation still returns the event