From 293bfe795d35cc0e9f05f57aa291abf428e87e2e Mon Sep 17 00:00:00 2001
From: Neil <4138956+nwparker@users.noreply.github.com>
Date: Sat, 24 Oct 2026 14:55:44 -0700
Subject: [PATCH] fix(browser): closing a host page retires a window-saved tab
 whose ids differ (STA-11998) (#33266)

---
 .../runtime/serve-browser-tab-layout.test.ts  | 26 +++++++++++++++++++
 src/main/runtime/serve-browser-tab-layout.ts  |  8 +++++-
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/src/main/runtime/serve-browser-tab-layout.test.ts b/src/main/runtime/serve-browser-tab-layout.test.ts
index d76eec740f5..7612e6088dd 100644
--- a/src/main/runtime/serve-browser-tab-layout.test.ts
+++ b/src/main/runtime/serve-browser-tab-layout.test.ts
@@ -118,6 +118,32 @@ describe('a browser tab a host with no window saves', () => {
     expect(saved.browserPagesByWorkspace?.['page-1']).toBeUndefined()
   })
 
+  it('leaves no trace once closed when a window saved it under its own tab ids (STA-11998)', () => {
+    const session = opened(sessionWithTerminal())
+    const browserTab = session.browserTabsByWorktree![WT]![0]!
+    const unifiedTab = session.unifiedTabs![WT]!.find((tab) => tab.id === 'page-1')!
+    const group = session.tabGroups![WT]![0]!
+    const windowSaved: WorkspaceSessionState = {
+      ...session,
+      browserTabsByWorktree: { [WT]: [{ ...browserTab, id: 'browser-tab-1' }] },
+      browserPagesByWorkspace: { 'browser-tab-1': session.browserPagesByWorkspace!['page-1']! },
+      unifiedTabs: {
+        [WT]: session.unifiedTabs![WT]!.map((tab) =>
+          tab === unifiedTab ? { ...tab, id: 'unified-1', entityId: 'browser-tab-1' } : tab
+        )
+      },
+      tabGroups: {
+        [WT]: [{ ...group, tabOrder: ['term-1', 'unified-1'], activeTabId: 'unified-1' }]
+      }
+    }
+
+    const saved = withClosedServeBrowserTab(HOST, windowSaved, WT, 'page-1')!
+
+    expect(saved.unifiedTabs?.[WT]?.map((tab) => tab.id)).toEqual(['term-1'])
+    expect(saved.browserTabsByWorktree?.[WT] ?? []).toEqual([])
+    expect(findSavedBrowserPage(saved, WT, 'page-1')).toBeNull()
+  })
+
   it('updates only the page of a window-saved tab that is not its active one', () => {
     const session = opened(sessionWithTerminal())
     const windowSaved: WorkspaceSessionState = {
diff --git a/src/main/runtime/serve-browser-tab-layout.ts b/src/main/runtime/serve-browser-tab-layout.ts
index 3e7aac27ada..ce0cad19cf1 100644
--- a/src/main/runtime/serve-browser-tab-layout.ts
+++ b/src/main/runtime/serve-browser-tab-layout.ts
@@ -189,7 +189,13 @@ export function withClosedServeBrowserTab(
   const loaded = loadWorkspaceLayout(hostId, session, nameBasedLoadContext())
   const applied = applyLayoutCommand(
     loaded.layout,
-    { type: 'closeTabs', workspace: worktreeId, tabIds: [saved.tabId], force: true },
+    {
+      type: 'closeTabs',
+      workspace: worktreeId,
+      // Why (STA-11998): closeTabs takes the tab-bar id, which a window-saved tab keeps apart.
+      tabIds: [savedBrowserTabEntryId(session, worktreeId, saved.tabId)],
+      force: true
+    },
     { mintId: randomUUID, mintLeafId: randomUUID, now: Date.now }
   )
   if (!applied.ok) {