From c91ea599d9fd92ea6e4cf5bcbcc22086b2f50031 Mon Sep 17 00:00:00 2001
From: Neil <4138956+nwparker@users.noreply.github.com>
Date: Sun, 7 Jun 2026 05:27:58 -0700
Subject: [PATCH] Track split OSC metadata in headless terminals (#4783)

---
 src/main/daemon/headless-emulator.test.ts | 27 +++++++++++++++++++++++
 src/main/daemon/headless-emulator.ts      | 22 ++++++++++++++++--
 2 files changed, 47 insertions(+), 2 deletions(-)

diff --git a/src/main/daemon/headless-emulator.test.ts b/src/main/daemon/headless-emulator.test.ts
index 3b3e42279..c6b09d5c8 100644
--- a/src/main/daemon/headless-emulator.test.ts
+++ b/src/main/daemon/headless-emulator.test.ts
@@ -109,6 +109,24 @@ describe('HeadlessEmulator', () => {
 
       expect(emulator.getSnapshot().cwd).toBe('/path/here')
     })
+
+    it('tracks OSC-7 CWD across split PTY chunks', async () => {
+      emulator = new HeadlessEmulator({ cols: 80, rows: 24 })
+
+      await emulator.write('\x1b]7;file:///split')
+      await emulator.write('/project\x07')
+
+      expect(emulator.getSnapshot().cwd).toBe('/split/project')
+    })
+
+    it('tracks OSC-7 CWD when ESC and OSC marker arrive in separate chunks', async () => {
+      emulator = new HeadlessEmulator({ cols: 80, rows: 24 })
+
+      await emulator.write('\x1b')
+      await emulator.write(']7;file:///split-escape\x07')
+
+      expect(emulator.getSnapshot().cwd).toBe('/split-escape')
+    })
   })
 
   describe('OSC title tracking', () => {
@@ -128,6 +146,15 @@ describe('HeadlessEmulator', () => {
       expect(emulator.getSnapshot().lastTitle).toBe('Codex idle')
     })
 
+    it('tracks OSC titles across split PTY chunks', async () => {
+      emulator = new HeadlessEmulator({ cols: 80, rows: 24 })
+
+      await emulator.write('\x1b]0;Codex work')
+      await emulator.write('ing\x07')
+
+      expect(emulator.getSnapshot().lastTitle).toBe('Codex working')
+    })
+
     it('adopts title metadata seeded from an external serializer', () => {
       emulator = new HeadlessEmulator({ cols: 80, rows: 24 })
 
diff --git a/src/main/daemon/headless-emulator.ts b/src/main/daemon/headless-emulator.ts
index 401a1a28e..54ade4c65 100644
--- a/src/main/daemon/headless-emulator.ts
+++ b/src/main/daemon/headless-emulator.ts
@@ -15,6 +15,7 @@ export type HeadlessSnapshotOptions = {
 }
 
 const DEFAULT_SCROLLBACK = 5000
+const OSC_SCAN_TAIL_LIMIT = 4096
 // Why: PTY/SSH chunks can split a long combined DECSET before the final h/l.
 // Keep parser state far beyond normal mode lists while still bounding memory.
 const PRIVATE_MODE_SCAN_TAIL_LIMIT = 4096
@@ -53,6 +54,7 @@ export class HeadlessEmulator {
   private serializer: SerializeAddon
   private cwd: string | null = null
   private lastTitle: string | null = null
+  private oscScanTail = ''
   private privateModeScanTail = ''
   private mouseTrackingMode: MouseTrackingMode = 'none'
   private sgrMouseMode = false
@@ -88,8 +90,10 @@ export class HeadlessEmulator {
       return Promise.resolve()
     }
 
-    this.scanOsc7(data)
-    const lastTitle = extractLastOscTitle(data)
+    const oscInput = this.oscScanTail + data
+    this.oscScanTail = this.extractOscScanTail(oscInput)
+    this.scanOsc7(oscInput)
+    const lastTitle = extractLastOscTitle(oscInput)
     if (lastTitle !== null) {
       this.lastTitle = lastTitle
     }
@@ -165,6 +169,20 @@ export class HeadlessEmulator {
     }
   }
 
+  private extractOscScanTail(input: string): string {
+    const lastOsc = input.lastIndexOf('\x1b]')
+    const lastEscape = input.endsWith('\x1b') ? input.length - 1 : -1
+    const start = Math.max(lastOsc, lastEscape)
+    if (start === -1) {
+      return ''
+    }
+    const suffix = input.slice(start)
+    if (suffix.includes('\x07') || suffix.includes('\x1b\\')) {
+      return ''
+    }
+    return suffix.slice(-OSC_SCAN_TAIL_LIMIT)
+  }
+
   private scanPrivateModes(data: string): void {
     const input = this.privateModeScanTail + data
     this.privateModeScanTail = this.extractPrivateModeScanTail(input)