From b5006b303e6005246d76e729cd857f70fb238985 Mon Sep 17 00:00:00 2001
From: tidely <43219534+tidely@users.noreply.github.com>
Date: Tue, 4 Nov 2025 12:17:01 +0200
Subject: [PATCH 1/4] Don't clone whole tab group eagerly

---
 crates/gpui/src/app.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crates/gpui/src/app.rs b/crates/gpui/src/app.rs
index d4bd7798187a5b..4d828a8eeac97a 100644
--- a/crates/gpui/src/app.rs
+++ b/crates/gpui/src/app.rs
@@ -421,7 +421,7 @@ impl SystemWindowTabController {
     /// Insert a tab into a tab group.
     pub fn add_tab(cx: &mut App, id: WindowId, tabs: Vec<SystemWindowTab>) {
         let mut controller = cx.global_mut::<SystemWindowTabController>();
-        let Some(tab) = tabs.clone().into_iter().find(|tab| tab.id == id) else {
+        let Some(tab) = tabs.iter().find(|tab| tab.id == id).cloned() else {
             return;
         };
 

From 913062e022f1bd6204c8cb34c90fedc21185a884 Mon Sep 17 00:00:00 2001
From: tidely <43219534+tidely@users.noreply.github.com>
Date: Tue, 4 Nov 2025 12:18:20 +0200
Subject: [PATCH 2/4] Drain & extend instead of clone & clear

---
 crates/gpui/src/app.rs | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/crates/gpui/src/app.rs b/crates/gpui/src/app.rs
index 4d828a8eeac97a..e719b1814eb63e 100644
--- a/crates/gpui/src/app.rs
+++ b/crates/gpui/src/app.rs
@@ -484,16 +484,14 @@ impl SystemWindowTabController {
             return;
         };
 
+        let initial_tabs_len = initial_tabs.len();
         let mut all_tabs = initial_tabs.clone();
-        for tabs in controller.tab_groups.values() {
-            all_tabs.extend(
-                tabs.iter()
-                    .filter(|tab| !initial_tabs.contains(tab))
-                    .cloned(),
-            );
+
+        for (_, mut tabs) in controller.tab_groups.drain() {
+            tabs.retain(|tab| !all_tabs[..initial_tabs_len].contains(tab));
+            all_tabs.extend(tabs);
         }
 
-        controller.tab_groups.clear();
         controller.tab_groups.insert(0, all_tabs);
     }
 

From 548243fa11471286f8d1cca2095c21891c0dbbe3 Mon Sep 17 00:00:00 2001
From: tidely <43219534+tidely@users.noreply.github.com>
Date: Tue, 4 Nov 2025 12:20:12 +0200
Subject: [PATCH 3/4] Remove unnecessary hashmap lookup

We unnecessarily looked for the group id and then looked it up in the
hashmap, when we could iterate through the group right away
---
 crates/gpui/src/app.rs | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/crates/gpui/src/app.rs b/crates/gpui/src/app.rs
index e719b1814eb63e..632f0c3a049501 100644
--- a/crates/gpui/src/app.rs
+++ b/crates/gpui/src/app.rs
@@ -341,12 +341,9 @@ impl SystemWindowTabController {
 
     /// Get all tabs in the same window.
     pub fn tabs(&self, id: WindowId) -> Option<&Vec<SystemWindowTab>> {
-        let tab_group = self
-            .tab_groups
-            .iter()
-            .find_map(|(group, tabs)| tabs.iter().find(|tab| tab.id == id).map(|_| *group))?;
-
-        self.tab_groups.get(&tab_group)
+        self.tab_groups
+            .values()
+            .find(|tabs| tabs.iter().any(|tab| tab.id == id))
     }
 
     /// Initialize the visibility of the system window tab controller.

From 71d0391aaf85ff2620d5772428ab367c12f92016 Mon Sep 17 00:00:00 2001
From: tidely <43219534+tidely@users.noreply.github.com>
Date: Tue, 4 Nov 2025 12:20:40 +0200
Subject: [PATCH 4/4] Add todo

---
 crates/gpui/src/app.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/crates/gpui/src/app.rs b/crates/gpui/src/app.rs
index 632f0c3a049501..6e91454d9b4011 100644
--- a/crates/gpui/src/app.rs
+++ b/crates/gpui/src/app.rs
@@ -296,6 +296,7 @@ impl SystemWindowTabController {
             .find_map(|(group, tabs)| tabs.iter().find(|tab| tab.id == id).map(|_| group));
 
         let current_group = current_group?;
+        // TODO: `.keys()` returns arbitrary order, what does "next" mean?
         let mut group_ids: Vec<_> = controller.tab_groups.keys().collect();
         let idx = group_ids.iter().position(|g| *g == current_group)?;
         let next_idx = (idx + 1) % group_ids.len();
@@ -320,6 +321,7 @@ impl SystemWindowTabController {
             .find_map(|(group, tabs)| tabs.iter().find(|tab| tab.id == id).map(|_| group));
 
         let current_group = current_group?;
+        // TODO: `.keys()` returns arbitrary order, what does "previous" mean?
         let mut group_ids: Vec<_> = controller.tab_groups.keys().collect();
         let idx = group_ids.iter().position(|g| *g == current_group)?;
         let prev_idx = if idx == 0 {