not really sure

src/wm.rs

@@ -3,6 +3,7 @@ use std::{
     cell::{Cell, RefCell, RefMut},
     collections::HashMap,
     ffi::CString,
+    hash::{Hash, Hasher},
     io::{Error, ErrorKind, Result},
     ptr::{null, null_mut},
     sync::Arc,
@@ -76,6 +77,14 @@ pub struct Client {
     window: Window,
 }
 
+impl PartialEq for Client {
+    fn eq(&self, other: &Self) -> bool {
+        self.window == other.window
+    }
+}
+
+impl Eq for Client {}
+
 pub struct XLibState {
     display: Display,
     root: Window,
@@ -352,9 +361,8 @@ impl WMState {
                 xlib::MapRequest => {
                     let event = unsafe { &event.map_request };
 
-					self.mut_state
-						.borrow_mut()
-						.clients
+                    let _ = self.mut_state.try_borrow_mut().and_then(|mut_state| {
+                        RefMut::map(mut_state, |t| &mut t.clients)
                             .entry(event.window)
                             .or_insert_with(|| {
                                 unsafe { xlib::XMapWindow(self.dpy(), event.window) };
@@ -362,6 +370,9 @@ impl WMState {
                                     window: event.window,
                                 })
                             });
+
+                        Ok(())
+                    });
                 }
                 xlib::UnmapNotify => {
                     let event = unsafe { &event.unmap };