xstate: Ignore Window/Drawable errors

Sometimes, windows will have actually been destroyed before we even
processed the events for it, so if we try to do something like get
properties on windows (as we do whenever a window is mapped) we will get
an error from the X server, but this is fine - we can just ignore this.

Should fix #16, #20, #22, etc.

tests/integration.rs

@@ -295,11 +295,18 @@ impl Connection {
         wid
     }
 
+    #[track_caller]
     fn map_window(&self, window: x::Window) {
         self.send_and_check_request(&x::MapWindow { window })
             .unwrap();
     }
 
+    #[track_caller]
+    fn destroy_window(&self, window: x::Window) {
+        self.send_and_check_request(&x::DestroyWindow { window })
+            .unwrap();
+    }
+
     fn set_property<P: x::PropEl>(
         &self,
         window: x::Window,
@@ -357,6 +364,13 @@ fn toplevel_flow() {
         x::ATOM_WM_NORMAL_HINTS,
         &[flags, 0, 0, 0, 0, 50, 100, 300, 400],
     );
+    println!("set title: window");
+    connection.set_property(
+        window,
+        x::ATOM_STRING,
+        x::ATOM_WM_NAME,
+        c"window".to_bytes(),
+    );
     connection.map_window(window);
     f.wait_and_dispatch();
 
@@ -514,3 +528,51 @@ fn input_focus() {
         |win, focus| assert_eq!(win, focus),
     );
 }
+
+#[test]
+fn quick_delete() {
+    let mut f = Fixture::new();
+    let connection = Connection::new(&f.display);
+
+    let window = connection.new_window(connection.root, 0, 0, 20, 20, false);
+    connection.map_window(window);
+    connection.set_property(
+        window,
+        x::ATOM_WM_HINTS,
+        x::ATOM_WM_HINTS,
+        &[WmHintsFlags::Input.bits(), 0],
+    );
+    connection.set_property(
+        window,
+        x::ATOM_STRING,
+        x::ATOM_WM_NAME,
+        c"bindow".to_bytes(),
+    );
+    connection.set_property(
+        window,
+        x::ATOM_STRING,
+        x::ATOM_WM_CLASS,
+        &[c"f".to_bytes_with_nul(), c"ssalc".to_bytes_with_nul()].concat(),
+    );
+    let flags = (WmSizeHintsFlags::ProgramMaxSize | WmSizeHintsFlags::ProgramMinSize).bits();
+    connection.set_property(
+        window,
+        x::ATOM_WM_SIZE_HINTS,
+        x::ATOM_WM_NORMAL_HINTS,
+        &[flags, 1, 2, 3, 4, 25, 50, 150, 200],
+    );
+    connection
+        .send_and_check_request(&x::ConfigureWindow {
+            window,
+            value_list: &[x::ConfigWindow::X(10), x::ConfigWindow::Y(40)],
+        })
+        .unwrap();
+    connection.destroy_window(window);
+    f.wait_and_dispatch();
+
+    let last_surf = f
+        .testwl
+        .last_created_surface_id()
+        .expect("No surface created");
+    assert_eq!(f.testwl.get_surface_data(last_surf), None);
+}