Turns out the culprit is /etc/bash_completion.d/acroread from package acroread, which redefines _filedir. That breaks normal completion in /etc/bash_completion. Marking invalid.
** Changed in: bash-completion (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/747738 Title: For many commands (ls, rm, cat), completion offers only path names -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs