grep: fix "--quiet" overwriting current output

When grep is called with the --quiet option, the pager is initialized despite not being used. When the pager is "less", anything output by previous commands and not ended with a newline is overwritten: $ echo -n aaa; echo bbb aaabbb $ echo -n aaa; git grep -q foo; echo bbb bbb This can be worked around, for example, by making sure STDOUT is not a TTY or more directly by setting git's pager to "cat": $ echo -n aaa; git grep -q foo > /dev/null; echo bbb aaabbb $ echo -n aaa; PAGER=cat git grep -q foo; echo bbb aaabbb But prevent calling the pager in the first place, which would also save an unnecessary fork(). Signed-off-by: Wilhelm Schuermann <wimschuermann@googlemail.com> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>