- exec -a "$0" so git.real sees the correct argv[0] (e.g. git-upload-pack)
and dispatches correctly; without this SSH clone was broken
- Check only $1 for "merge-file" instead of scanning all args, preventing
accidental ifcmerge invocation from commit messages or other arg positions
- Use absolute path /usr/local/bin/ifcmerge to prevent PATH hijacking
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>