advise the mux when a domain has detached; remove its tabs

src/mux/mod.rs

@@ -201,10 +201,16 @@ impl Mux {
     pub fn remove_tab(&self, tab_id: TabId) {
         debug!("removing tab {}", tab_id);
         self.tabs.borrow_mut().remove(&tab_id);
+        self.prune_dead_windows();
+    }
+
+    pub fn prune_dead_windows(&self) {
+        let live_tab_ids: Vec<TabId> = self.tabs.borrow().keys().cloned().collect();
         let mut windows = self.windows.borrow_mut();
         let mut dead_windows = vec![];
         for (window_id, win) in windows.iter_mut() {
-            if win.remove_by_id(tab_id) && win.is_empty() {
+            win.prune_dead_tabs(&live_tab_ids);
+            if win.is_empty() {
                 dead_windows.push(*window_id);
             }
         }
@@ -273,6 +279,15 @@ impl Mux {
     pub fn iter_domains(&self) -> Vec<Arc<dyn Domain>> {
         self.domains.borrow().values().cloned().collect()
     }
+
+    pub fn domain_was_detached(&self, domain: DomainId) {
+        self.tabs
+            .borrow_mut()
+            .retain(|_tab_id, tab| tab.domain_id() != domain);
+        // Ideally we'd do this here, but that seems to cause problems
+        // at the moment:
+        // self.prune_dead_windows();
+    }
 }
 
 #[derive(Debug, Fail)]

src/mux/window.rs

@@ -85,4 +85,25 @@ impl Window {
     pub fn iter(&self) -> impl Iterator<Item = &Rc<dyn Tab>> {
         self.tabs.iter()
     }
+
+    pub fn prune_dead_tabs(&mut self, live_tab_ids: &[TabId]) {
+        let dead: Vec<TabId> = self
+            .tabs
+            .iter()
+            .filter_map(|tab| {
+                if live_tab_ids
+                    .iter()
+                    .find(|&&id| id == tab.tab_id())
+                    .is_none()
+                {
+                    Some(tab.tab_id())
+                } else {
+                    None
+                }
+            })
+            .collect();
+        for tab_id in dead {
+            self.remove_by_id(tab_id);
+        }
+    }
 }

src/server/domain.rs

@@ -99,6 +99,8 @@ impl ClientDomain {
     pub fn perform_detach(&self) {
         log::error!("detached domain {}", self.local_domain_id);
         self.inner.borrow_mut().take();
+        let mux = Mux::get().unwrap();
+        mux.domain_was_detached(self.local_domain_id);
     }
 
     pub fn remote_to_local_tab_id(&self, remote_tab_id: TabId) -> Option<TabId> {