Workspace files truncated to 0 bytes (Local History since 2026-08-07)

Support Bug Reports
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Bug Report: Multiple workspace files truncated to 0 bytes without attributable write

Date observed: 2026-08-11 (local empty on disk); Local History empty snapshots since 2026-08-07 ~10:05
Cursor version: 3.15.6 (commit a1f686545fd0ce8917bbd2449f733551a9bce420, stable)
OS: macOS 26.5.2 (Darwin 25.5.0, arm64, Apple Silicon)
Repos: simulation-training-manage-web and (update) simulation-training-user-web, both branch test (Git working tree only; remote untouched)

Summary

Four tracked source files in the workspace were truncated to empty (0 bytes) as uncommitted local changes. Remote/HEAD content remained intact. No git commit author, no shell truncate command, and no Agent Write tool call in the investigating chat could be attributed. Cursor Local History began recording 0-byte snapshots for these files starting at the Cursor session that began 2026-08-07 10:05, and continued across later sessions.

Affected files (at time of discovery)

  • src/views/asset/AssetIndex.vue (~2628 lines → 0)
  • src/views/root-cause/RootCauseIndex.vue (~1626 lines → 0)
  • src/views/login/OaLoginPage.vue (~114 lines → 0)
  • src/views/login/OaLoginExpiredPage.vue (~54 lines → 0)

git diff --numstat showed 0 <old_line_count> for each (pure deletion). Git blob hash after truncate was empty blob e69de29.

Timeline / evidence

  1. 2026-08-07 ~08:59 — Local History still had full content (e.g. AssetIndex history entry Fk3C.vue = 76862 bytes, matching HEAD).
  2. 2026-08-07 ~10:05 — New Cursor log session logs/20260807T100504. Immediately afterward, Local History entries for the four files become 0 bytes (e.g. AssetIndex NVDH.vue, RootCause x5ry.vue / V6EM.vue).
  3. 2026-08-10 / 2026-08-11 morning — Further 0-byte Local History snapshots at Cursor session times (08:31, 08:40, 08:55, 09:24, 10:15).
  4. 2026-08-11 10:14 — User inspected SCM diffs; Git extension logged git show HEAD:... for all four files (already showing as modified/empty vs HEAD).
  5. 2026-08-11 10:15:48 — git pull --tags origin test (fast-forward 402b158..def0b58). Empty working-tree state predated and persisted around this.
  6. 2026-08-11 10:16:22 — All four files on disk had the same mtime, size 0 (batch truncate/write).
  7. Investigating Agent chat started ~10:16; only read/git commands — did not write these files. Restored later via git restore.

Local History paths (for Cursor eng)

  • ~/Library/Application Support/Cursor/User/History/5961af8c/ → AssetIndex.vue
  • ~/Library/Application Support/Cursor/User/History/12daffe1/ → RootCauseIndex.vue
  • ~/Library/Application Support/Cursor/User/History/36d5e605/ → OaLoginPage.vue
  • ~/Library/Application Support/Cursor/User/History/5ba315ce/ → OaLoginExpiredPage.vue

Cursor logs of interest

  • ~/Library/Application Support/Cursor/logs/20260807T100504/ (first empty Local History wave)
  • ~/Library/Application Support/Cursor/logs/20260811T083125/window2/exthost/vscode.git/Git.log (10:14+ SCM inspection)
  • ~/Library/Application Support/Cursor/logs/20260811T083125/window4_wb9/exthost/vscode.git/Git.workspaceId-*.log (10:16+ diff of the four files)

What we ruled out

  • Not a remote/git commit (origin/test still had full content; change was unstaged local only)
  • Not the investigating Agent turn (no Write/Delete; files already empty in SCM before that chat)
  • No matching truncate/> patterns in recent zsh history for these paths

Suspected area (unproven)

Hot Exit / editor tab restore / Local History save path writing empty buffers back to disk across session restarts — correlation with session start times is strong, but root cause was not proven from available logs.

Impact

Silent data loss in the working tree for large source files. Recoverable only because Git HEAD still had content. High trust impact.

Workaround used

git restore src/views/asset/AssetIndex.vue \
  src/views/root-cause/RootCauseIndex.vue \
  src/views/login/OaLoginPage.vue \
  src/views/login/OaLoginExpiredPage.vue

Working tree clean after restore; line counts match prior HEAD.

Update 2026-08-11: Also reproduced in sibling project simulation-training-user-web

Repo: /Users/huabo/dev/yzsz/jl/simulation-training-user-web (branch test)

Affected

  • src/views/MainLayout.vue (258 lines → 0 bytes)

Disk mtime at discovery/restore time: 2026-08-11 09:24:46 (same clock bucket as manage-web Local History empty snapshots at 09:24).

Local History

  • ~/Library/Application Support/Cursor/User/History/c3b728/ → MainLayout.vue
  • Last good content: Aug 7 ~08:59 / 10:05 (faOl.vue / earlier = 6839 bytes)
  • Empty snapshots from 2026-08-07 10:05 onward (same Cursor session wave as manage-web), then Aug 10 and Aug 11 morning session times (08:31, 08:40, 08:55, 09:24)

Scan

  • Only this one empty tracked file under src/ at check time; no other zero-byte tracked files after restore.
  • Restored with git restore src/views/MainLayout.vue (258 lines restored).

Cross-repo implication

Same failure mode across two separate Git repos opened in Cursor, with empty Local History starting in the same Cursor session (20260807T100504). Stronger evidence this is an editor/session restore issue rather than a one-off accidental edit in a single project.

Steps to Reproduce

This is intermittent and we could not find a 100% reliable one-click repro. Closest observed sequence:

  1. Open multiple Cursor windows/workspaces, including at least:
    • simulation-training-manage-web
    • simulation-training-user-web
  2. Keep several large Vue source files open across sessions (or previously opened so Hot Exit / Local History tracks them), e.g.:
    • AssetIndex.vue, RootCauseIndex.vue, OaLoginPage.vue, OaLoginExpiredPage.vue
    • MainLayout.vue (user-web)
  3. Quit / restart Cursor (or leave it running across multiple session starts).
  4. After a later session start, check git status / Source Control.
  5. Observe that one or more tracked files are truncated to 0 bytes as unstaged local changes (git empty blob e69de29), while HEAD/remote still have full content.

Observed correlation (not proven causal):

  • Empty Local History snapshots for the affected files began in Cursor session logs/20260807T100504 (~2026-08-07 10:05).
  • Further 0-byte Local History entries appeared at later session times (Aug 10 / Aug 11 morning).
  • On 2026-08-11, manage-web’s 4 files shared the same disk mtime when truncated; user-web MainLayout.vue was also empty around the same morning window.
  • No Agent Write/Delete and no shell truncate command could be attributed for the investigating turn.

Workaround:
git restore

Operating System

MacOS

Version Information

Version Information

  • Cursor: 3.15.6 (stable)
  • Commit: a1f686545fd0ce8917bbd2449f733551a9bce420
  • OS: macOS 26.5.2 (Build 25F84)
  • Arch: arm64 (Apple Silicon)
  • Date of report: 2026-08-12

Does this stop you from using Cursor

No - Cursor works, but with this issue

7

Hey there,

What you’re describing isn’t intended behavior, and it’s not caused by anything on your end. It’s an issue we’re tracking.

One thing that matters for your case: git restore fixed the files on disk, but it doesn’t clear the pending Agent (Create Diff) changes that trigger this, so those files can get re-emptied on a future launch until you resolve them in Cursor:

  1. Open Review Changes and resolve every pending Agent change (Keep All / Undo All) - wait until the list is empty before quitting or updating.
  2. For a restored file still showing as pending, confirm the content is visible, then choose Keep (not Undo - Undo would blank it again).
  3. Commit frequently as a safety net.

files.autoSave / files.hotExit don’t affect this path. I’ll post here when there’s an update.