git pull fails updating ORIG_HEAD on Windows in 2.54.0.windows.1

### Existing issues matching what you're seeing - [x] I was not able to find an open or closed issue matching what I'm seeing ### Git for Windows version ```shell git version 2.54.0.windows.1 cpu: x86_64 built from commit: 2b8a3ab140826ac423c2845ef81d4c6ac4f7bf3c sizeof-long: 4 sizeof-size_t: 8 shell-path: D:/git-sdk-64-build-installers/usr/bin/sh rust: disabled feature: fsmonitor--daemon gettext: enabled libcurl: 8.19.0 OpenSSL: OpenSSL 3.5.6 7 Apr 2026 zlib: 1.3.2 SHA-1: SHA1_DC SHA-256: SHA256_BLK default-ref-format: files default-hash: sha1 ``` ### Windows version Windows 11 ### Windows CPU architecture x86_64 (64-bit) ### Additional Windows version information ```shell Microsoft Windows [Versión 10.0.26200.8457] ``` ### Options set during installation ```shell Editor Option: VIM Custom Editor Path: Default Branch Option: Path Option: Cmd SSH Option: OpenSSH Tortoise Option: false CURL Option: OpenSSL CRLF Option: CRLFAlways Bash Terminal Option: MinTTY Git Pull Behavior Option: Merge Use Credential Manager: Enabled Performance Tweaks FSCache: Enabled Enable Symlinks: Disabled Enable FSMonitor: Disabled ``` ### Other interesting things `git fsck --full` reports a healthy repository. `git fetch origin` succeeds. `git push --dry-run origin master` succeeds. `git update-ref ORIG_HEAD HEAD` fails with the same error. The persistent reproduction happened without a stale `ORIG_HEAD.lock` present. The issue also breaks VS Code Sync Changes. ### Terminal/shell PowerShell 5.1 from VS Code ### Commands that trigger the issue ```shell git pull --ff-only origin master Also reproducible with: git update-ref ORIG_HEAD HEAD ``` ### Expected behaviour `git pull --ff-only origin master` should succeed or report `Already up to date.` when there is nothing to merge. Updating `ORIG_HEAD` should not fail in this no-op or ahead-only case. ### Actual behaviour Git fails with: ```text fatal: update_ref failed for ref 'ORIG_HEAD': couldn't set 'ORIG_HEAD' ``` This also breaks VS Code Sync Changes because the pull step fails. `FETCH_HEAD` can be equal to or behind local `HEAD`, so there is no real merge/update work to do, yet the command still aborts on `ORIG_HEAD`. ### Repository _No response_