Grep over tramp fails to insert header in its output buffer. (I remember
reporting this bug, but I didn't notice it was about tramp then; I tried
with 'emacs -q' now).

For example, run from *scratch*, as 'M-x grep RET grep -nH -e xxx xxx RET':

    -*- mode: grep; default-directory: "~/" -*-
    Grep started at Thu Dec 12 14:33:28

    grep -nH -e xxx xxx
    grep: xxx: No such file or directory

    Grep exited abnormally with code 2 at Thu Dec 12 14:33:28

But when run from a "tramped" buffer ('/sudo:root@localhost', but
apparently true for any other case too) in the same way:

    grep: xxx: No such file or directory

    Grep exited abnormally with code 2 at Thu Dec 12 14:35:53

Version: GNU Emacs 24.3.50.1 (x86_64-unknown-linux-gnu, GTK+ Version 3.8.6)
of 2013-12-04 on gonzo.localdomain

Paul