feat(zellij-server): restore tab position when re-attaching

Author: XOR-op

zellij-server/src/screen.rs

@@ -692,6 +692,7 @@ pub(crate) struct Screen {
     connected_clients: Rc<RefCell<HashSet<ClientId>>>,
     /// The indices of this [`Screen`]'s active [`Tab`]s.
     active_tab_indices: BTreeMap<ClientId, usize>,
+    global_last_active_tab_index: usize,
     tab_history: BTreeMap<ClientId, Vec<usize>>,
     mode_info: BTreeMap<ClientId, ModeInfo>,
     default_mode_info: ModeInfo, // TODO: restructure ModeInfo to prevent this duplication
@@ -764,6 +765,7 @@ impl Screen {
             style: client_attributes.style,
             connected_clients: Rc::new(RefCell::new(HashSet::new())),
             active_tab_indices: BTreeMap::new(),
+            global_last_active_tab_index: 0,
             tabs: BTreeMap::new(),
             overlay: OverlayWindow::default(),
             terminal_emulator_colors: Rc::new(RefCell::new(Palette::default())),
@@ -1523,6 +1525,8 @@ impl Screen {
             self.active_tab_indices.iter().next()
         {
             *first_active_tab_index
+        } else if self.tabs.contains_key(&self.global_last_active_tab_index) {
+            self.global_last_active_tab_index
         } else if self.tabs.contains_key(&0) {
             0
         } else if let Some(tab_index) = self.tabs.keys().next() {
@@ -1551,6 +1555,7 @@ impl Screen {
             }
         }
         if self.active_tab_indices.contains_key(&client_id) {
+            self.global_last_active_tab_index = *self.active_tab_indices.get(&client_id).unwrap();
             self.active_tab_indices.remove(&client_id);
         }
         if self.tab_history.contains_key(&client_id) {