Pseudo console is not released when nested native processes are moved to the background, corrupting readline completion

[nho-axentia]

Existing issues matching what you're seeing

• I was not able to find an open or closed issue matching what I'm seeing

Git for Windows version

git version 2.55.0.windows.5
cpu: x86_64
built from commit: 32c4f7689275d233577576630e1ac5b7eb354eb0
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: 8.21.0
OpenSSL: OpenSSL 3.5.7 9 Jun 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

Microsoft Windows [Version 10.0.26200.9168]

Options set during installation

Editor Option: VIM
Custom Editor Path:
Default Branch Option: main
Path Option: Cmd
SSH Option: OpenSSH
Tortoise Option: false
CURL Option: WinSSL
CRLF Option: LFOnly
Bash Terminal Option: MinTTY
Git Pull Behavior Option: FFOnly
Use Credential Manager: Enabled
Performance Tweaks FSCache: Enabled
Enable Symlinks: Enabled
Enable FSMonitor: Disabled

Other interesting things

• msys2-runtime: MINGW64_NT-10.0-26200 3.6.10-710e5275.x86_64 2026-07-28 09:32 UTC
• mintty 3.8.3 (2026-06-09)
• bash 5.3.15(2)-release

Disabling the pseudo console by setting MSYS=disable_pcon avoids the issue.

Terminal/shell

mintty 3.8.3 (Git Bash), bash 5.3.15

Commands that trigger the issue

In a Git Bash (mintty) window, in a repository with a branch named `foobar`:


# Start and put to the backround a native Windows process that itself keeps a second native process alive
cmd //c 'C:\Windows\System32\waitfor.exe /t 60 zzz' &

# Attempt to use tab-completion with a git command, e.g:
git switch f<TAB>


Once the backgrounded command finishes (or is killed) the problem disappears.

Expected behaviour

Pressing tab completes the branch name:

git switch foobar

Actual behaviour

The completion is drawn about 64 columns to the right of where the cursor should be:

$ git switch f                                                                oobar

A mintty output log (mintty -l /tmp/mintty.log -e bash -il) shows that readline emits
only oobar; the displacement comes from cursor-forward sequences injected between the
typed text and the completion:

git switch f^[[12C^[[12C^[[12C^[[12C^[[12C^[[4Coobar

Repository

No response