From 3aa03b3348bc04441a384edcbf338a8cee362162 Mon Sep 17 00:00:00 2001
From: Neil <4138956+nwparker@users.noreply.github.com>
Date: Sun, 31 May 2026 05:37:48 -0700
Subject: [PATCH] fix: persist default tab session patch marker (#4135)

---
 .../src/lib/workspace-session-patch.test.ts   | 21 +++++++++++++++++++
 .../src/lib/workspace-session-patch.ts        |  7 +++++++
 2 files changed, 28 insertions(+)

diff --git a/src/renderer/src/lib/workspace-session-patch.test.ts b/src/renderer/src/lib/workspace-session-patch.test.ts
index 6cd341916ce..15ce28d72ad 100644
--- a/src/renderer/src/lib/workspace-session-patch.test.ts
+++ b/src/renderer/src/lib/workspace-session-patch.test.ts
@@ -156,4 +156,25 @@ describe('buildWorkspaceSessionPatch', () => {
     expect(Object.hasOwn(patch, 'activeConnectionIdsAtShutdown')).toBe(true)
     expect(patch.activeConnectionIdsAtShutdown).toBeUndefined()
   })
+
+  it('persists default terminal tab idempotency marker changes', () => {
+    const patch = buildWorkspaceSessionPatch(
+      createSnapshot({ defaultTerminalTabsAppliedByWorktreeId: { 'wt-1': true } }),
+      ['defaultTerminalTabsAppliedByWorktreeId']
+    )
+
+    expect(patch).toEqual({
+      defaultTerminalTabsAppliedByWorktreeId: { 'wt-1': true }
+    })
+  })
+
+  it('keeps default terminal tab marker clearing keys in patches', () => {
+    const patch = buildWorkspaceSessionPatch(
+      createSnapshot({ defaultTerminalTabsAppliedByWorktreeId: {} }),
+      ['defaultTerminalTabsAppliedByWorktreeId']
+    )
+
+    expect(Object.hasOwn(patch, 'defaultTerminalTabsAppliedByWorktreeId')).toBe(true)
+    expect(patch.defaultTerminalTabsAppliedByWorktreeId).toBeUndefined()
+  })
 })
diff --git a/src/renderer/src/lib/workspace-session-patch.ts b/src/renderer/src/lib/workspace-session-patch.ts
index 8e0d9ab8460..ade50fe4f6f 100644
--- a/src/renderer/src/lib/workspace-session-patch.ts
+++ b/src/renderer/src/lib/workspace-session-patch.ts
@@ -122,6 +122,13 @@ export function buildWorkspaceSessionPatch(
   if (changed.has('lastVisitedAtByWorktreeId')) {
     patch.lastVisitedAtByWorktreeId = buildLastVisitedAtByWorktreeId(snapshot)
   }
+  if (changed.has('defaultTerminalTabsAppliedByWorktreeId')) {
+    patch.defaultTerminalTabsAppliedByWorktreeId =
+      snapshot.defaultTerminalTabsAppliedByWorktreeId &&
+      Object.keys(snapshot.defaultTerminalTabsAppliedByWorktreeId).length > 0
+        ? snapshot.defaultTerminalTabsAppliedByWorktreeId
+        : undefined
+  }
 
   return patch
 }