From 8b8ba0d2070945456fb09adf0e296d1dfb0ea6e1 Mon Sep 17 00:00:00 2001
From: Ryan Harrington <ryan.harrington@ithaka.org>
Date: Mon, 16 Mar 2026 16:45:21 -0400
Subject: [PATCH] fix/gsd-bg-shell-stale-cwd: resync bg-shell cwd after
 auto-worktree exit

---
 src/resources/extensions/bg-shell/index.ts    | 16 +++++++--
 .../extensions/bg-shell/utilities.ts          | 16 +++++++++
 src/tests/bg-shell-persistence-cwd.test.ts    | 36 +++++++++++++++++++
 3 files changed, 66 insertions(+), 2 deletions(-)
 create mode 100644 src/tests/bg-shell-persistence-cwd.test.ts

diff --git a/src/resources/extensions/bg-shell/index.ts b/src/resources/extensions/bg-shell/index.ts
index e126c12f1..8f950d28d 100644
--- a/src/resources/extensions/bg-shell/index.ts
+++ b/src/resources/extensions/bg-shell/index.ts
@@ -64,7 +64,7 @@ import {
 } from "./output-formatter.js";
 import { waitForReady } from "./readiness-detector.js";
 import { queryShellEnv, sendAndWait, runOnSession } from "./interaction.js";
-import { formatUptime, formatTokenCount } from "./utilities.js";
+import { formatUptime, formatTokenCount, resolveBgShellPersistenceCwd } from "./utilities.js";
 import { BgManagerOverlay } from "./overlay.js";
 
 // ── Re-exports for consumers ───────────────────────────────────────────────
@@ -81,6 +81,14 @@ export { BgManagerOverlay } from "./overlay.js";
 export default function (pi: ExtensionAPI) {
 	let latestCtx: ExtensionContext | null = null;
 
+	function syncLatestCtxCwd(): void {
+		if (!latestCtx) return;
+		const syncedCwd = resolveBgShellPersistenceCwd(latestCtx.cwd);
+		if (syncedCwd !== latestCtx.cwd) {
+			latestCtx = { ...latestCtx, cwd: syncedCwd };
+		}
+	}
+
 	// Clean up on session shutdown
 	pi.on("session_shutdown", async () => {
 		cleanupAll();
@@ -1519,6 +1527,7 @@ export default function (pi: ExtensionAPI) {
 		refreshWidget();
 		// Persist manifest periodically
 		if (latestCtx) {
+			syncLatestCtxCwd();
 			persistManifest(latestCtx.cwd);
 		}
 	}, 2000);
@@ -1567,7 +1576,10 @@ export default function (pi: ExtensionAPI) {
 	// Clean up on shutdown
 	pi.on("session_shutdown", async () => {
 		clearInterval(maintenanceInterval);
-		if (latestCtx) persistManifest(latestCtx.cwd);
+		if (latestCtx) {
+			syncLatestCtxCwd();
+			persistManifest(latestCtx.cwd);
+		}
 		cleanupAll();
 	});
 }
diff --git a/src/resources/extensions/bg-shell/utilities.ts b/src/resources/extensions/bg-shell/utilities.ts
index b33c68b50..9d534a2ee 100644
--- a/src/resources/extensions/bg-shell/utilities.ts
+++ b/src/resources/extensions/bg-shell/utilities.ts
@@ -3,6 +3,8 @@
  */
 
 import { createRequire } from "node:module";
+import { existsSync } from "node:fs";
+import { sep } from "node:path";
 
 // ── Windows VT Input Restoration ────────────────────────────────────────────
 // Child processes (esp. Git Bash / MSYS2) can strip the ENABLE_VIRTUAL_TERMINAL_INPUT
@@ -53,3 +55,17 @@ export function formatTokenCount(count: number): string {
 	if (count < 10000000) return `${(count / 1000000).toFixed(1)}M`;
 	return `${Math.round(count / 1000000)}M`;
 }
+
+export function resolveBgShellPersistenceCwd(
+	cachedCwd: string,
+	liveCwd = process.cwd(),
+	pathExists: (path: string) => boolean = existsSync,
+): string {
+	const worktreeMarker = `${sep}.gsd${sep}worktrees${sep}`;
+	const cachedIsAutoWorktree = cachedCwd.includes(worktreeMarker);
+	if (!cachedIsAutoWorktree) return cachedCwd;
+	if (cachedCwd === liveCwd && pathExists(cachedCwd)) return cachedCwd;
+	if (!pathExists(cachedCwd)) return liveCwd;
+	if (liveCwd !== cachedCwd) return liveCwd;
+	return cachedCwd;
+}
diff --git a/src/tests/bg-shell-persistence-cwd.test.ts b/src/tests/bg-shell-persistence-cwd.test.ts
new file mode 100644
index 000000000..f686beb28
--- /dev/null
+++ b/src/tests/bg-shell-persistence-cwd.test.ts
@@ -0,0 +1,36 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+import { resolveBgShellPersistenceCwd } from "../resources/extensions/bg-shell/utilities.ts";
+
+test("keeps non-worktree cwd unchanged", () => {
+  const cached = "/repo";
+  const live = "/repo";
+  assert.equal(resolveBgShellPersistenceCwd(cached, live, () => true), cached);
+});
+
+test("rewrites stale auto-worktree cwd to live cwd after exit", () => {
+  const cached = "/repo/.gsd/worktrees/M001";
+  const live = "/repo";
+  assert.equal(
+    resolveBgShellPersistenceCwd(cached, live, (path) => path === live),
+    live,
+  );
+});
+
+test("rewrites mismatched auto-worktree cwd to live cwd even if old path still exists", () => {
+  const cached = "/repo/.gsd/worktrees/M001";
+  const live = "/repo";
+  assert.equal(
+    resolveBgShellPersistenceCwd(cached, live, () => true),
+    live,
+  );
+});
+
+test("keeps current auto-worktree cwd when it still matches process cwd", () => {
+  const cached = "/repo/.gsd/worktrees/M001";
+  assert.equal(
+    resolveBgShellPersistenceCwd(cached, cached, () => true),
+    cached,
+  );
+});