From 278b02b27ab5cad4d32f8aadb9352ea09e885ff7 Mon Sep 17 00:00:00 2001
From: OrcaWin <alpha-eng@stably.ai>
Date: Wed, 28 Oct 2026 12:51:45 -0700
Subject: [PATCH] fix(files): preserve WSL filenames in watcher snapshots
 (#34855)

* fix(files): preserve WSL filenames in watcher snapshots

* test(files): drop shell-producer WSL snapshot test

---------

Co-authored-by: OrcaWin <293788423+OrcaWin@users.noreply.github.com>
---
 .../watchers/filesystem-watcher-wsl.test.ts   | 32 +++++++++++++++++--
 .../watchers/filesystem-watcher-wsl.ts        | 14 ++++----
 2 files changed, 37 insertions(+), 9 deletions(-)

diff --git a/src/main/ipc/filesystem/watchers/filesystem-watcher-wsl.test.ts b/src/main/ipc/filesystem/watchers/filesystem-watcher-wsl.test.ts
index bc533eaeb21..0052db17899 100644
--- a/src/main/ipc/filesystem/watchers/filesystem-watcher-wsl.test.ts
+++ b/src/main/ipc/filesystem/watchers/filesystem-watcher-wsl.test.ts
@@ -19,8 +19,8 @@ import {
 } from '../watcher-process/parcel-watcher-child-registry'
 import type { WatchedRoot, WslWatcherDeps } from './filesystem-watcher-wsl'
 
-const SNAPSHOT_START = '\x1e'
-const SNAPSHOT_END = '\x1f'
+const SNAPSHOT_START = '\0\x1e\0'
+const SNAPSHOT_END = '\0\x1f\0'
 const ROOT_KEY = '\\\\wsl.localhost\\Ubuntu\\home\\me\\repo'
 
 class FakeChildProcess extends EventEmitter {
@@ -173,6 +173,34 @@ describe('createWslWatcher', () => {
     ])
   })
 
+  it('preserves control characters in filenames across byte-split snapshot frames', async () => {
+    const { child, promise, deps } = startWatcher()
+    child.stdout.write(snapshotFrame([]))
+    const root = await promise
+    const names = [
+      'start\x1einside.txt',
+      'end\x1finside.txt',
+      'trailing\x1f',
+      'tab\tline\n漢字.txt'
+    ]
+    const frame = (mtime: string) =>
+      snapshotFrame(names.map((name) => ['f', mtime, `/home/me/repo/${name}`]))
+    for (const mtime of ['1.0', '2.0']) {
+      for (const byte of Buffer.from(frame(mtime))) {
+        child.stdout.write(Buffer.from([byte]))
+      }
+    }
+    child.stdout.write(snapshotFrame([]))
+
+    expect(root.batch.events).toEqual(
+      ['create', 'update', 'delete'].flatMap((type) =>
+        names.map((name) => ({ type, path: `${ROOT_KEY}\\${name}` }))
+      )
+    )
+    expect(deps.scheduleBatchFlush).toHaveBeenCalledTimes(3)
+    await root.subscription.unsubscribe()
+  })
+
   it('turns watcher exit into an overflow refresh without retaining UNC paths', async () => {
     const scheduleBatchFlush = vi.fn()
     const deps = makeDeps(scheduleBatchFlush)
diff --git a/src/main/ipc/filesystem/watchers/filesystem-watcher-wsl.ts b/src/main/ipc/filesystem/watchers/filesystem-watcher-wsl.ts
index 7850d83d2b9..0e83142fb9f 100644
--- a/src/main/ipc/filesystem/watchers/filesystem-watcher-wsl.ts
+++ b/src/main/ipc/filesystem/watchers/filesystem-watcher-wsl.ts
@@ -32,7 +32,7 @@ export type WslWatcherDeps = {
 
 const POLL_INTERVAL_SECONDS = 2
 const STARTUP_TIMEOUT_MS = 10_000
-const [SNAPSHOT_START, SNAPSHOT_END] = ['\x1e', '\x1f']
+const [SNAPSHOT_START, SNAPSHOT_END] = ['\0\x1e\0', '\0\x1f\0']
 const MAX_STREAM_BUFFER_CHARS = 10 * 1024 * 1024
 
 type WslSnapshotEntry = {
@@ -68,11 +68,11 @@ function buildSnapshotScript(ignoreDirs: readonly string[]): string {
     'set -efu',
     'root=$1',
     'while :; do',
-    "  printf '\\036'",
+    "  printf '\\000\\036\\000'",
     '  if [ -d "$root" ]; then',
     `    find "$root" -mindepth 1 -maxdepth 2 ${prune} -printf '%y\\t%T@\\t%p\\0' 2>/dev/null || true`,
     '  fi',
-    "  printf '\\037'",
+    "  printf '\\000\\037\\000'",
     `  sleep ${POLL_INTERVAL_SECONDS} || exit 0`,
     'done'
   ].join('\n')
@@ -211,13 +211,13 @@ export async function createWslWatcher(
     while (true) {
       const start = streamBuffer.indexOf(SNAPSHOT_START)
       if (start === -1) {
-        streamBuffer = streamBuffer.slice(-1)
+        streamBuffer = streamBuffer.slice(-(SNAPSHOT_START.length - 1))
         return
       }
       if (start > 0) {
         streamBuffer = streamBuffer.slice(start)
       }
-      const end = streamBuffer.indexOf(SNAPSHOT_END, 1)
+      const end = streamBuffer.indexOf(SNAPSHOT_END, SNAPSHOT_START.length)
       if (end === -1) {
         if (streamBuffer.length > MAX_STREAM_BUFFER_CHARS) {
           streamBuffer = ''
@@ -226,8 +226,8 @@ export async function createWslWatcher(
         }
         return
       }
-      const frame = streamBuffer.slice(1, end)
-      streamBuffer = streamBuffer.slice(end + 1)
+      const frame = streamBuffer.slice(SNAPSHOT_START.length, end)
+      streamBuffer = streamBuffer.slice(end + SNAPSHOT_END.length)
       ingestFrame(frame)
     }
   }