Refresh managed tmux commands after reconnect
Fixes #12936.
When cmux reconnects to an existing remote tmux session, it rebinds the current relay environment but leaves the session's cmux-managed default-command unchanged. User-created panes can therefore keep launching through a deleted relay rcfile and lose the normal login-shell PATH.
The reconnect command now reads the existing default command and refreshes it only when it contains cmux's managed helper or integration markers. User-authored tmux defaults remain untouched. Added a regression test proving a stale managed command is replaced before attach, while the existing test continues to cover preservation of unrecognized options.
Testing
python3 scripts/verify-local.py --affected mf/main- Swift parse of the changed source and tests
git diff --check- SwiftPM test attempt was blocked by unrelated compiler type-check timeouts in existing CmuxFoundation tests
Changelog
Remote tmux user-created panes regain the current cmux shell integration after reconnect instead of retaining a stale relay rcfile.
Demo Video
Not included. The reconnect command and guarded option update are covered by deterministic command-builder tests.
Checklist
- Refreshes only cmux-managed defaults
- Preserves user-authored tmux options
- Adds reconnect regression coverage
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Summary by cubic
Fixes #12936 so reconnecting to an existing remote tmux session refreshes a stale cmux-managed default-command, keeping user-created panes on the current shell integration instead of a deleted relay rcfile.
- Reconnect reads the session's
default-commandand resets it only when it contains cmux's managed helper or shell integration markers; a failed refresh aborts before attach with remote diagnostics suppressed. - User-authored tmux defaults remain untouched.
- Adds regression coverage for the replace-before-attach and abort-on-failure paths; an existing test covers preservation of unrecognized options.
Summary by CodeRabbit
- Bug Fixes
- Fixed attachment to existing tmux sessions by refreshing outdated cmux-managed shell commands before connecting. Existing custom commands remain unchanged. If the refresh fails, attachment stops and returns the tmux failure status rather than continuing with an outdated command.