grep -w accepts matches between non-word characters, only. If a match
from regexec() doesn't meet this criteria, grep continues its search
after the first character of that match.
We can be a bit smarter here and skip all positions that follow a word
character first, as they can't match our criteria. This way we can
consume characters quite cheaply and don't need to special-case the
handling of the beginning of a line.
Here's a contrived example command on msysgit (best of five runs):
$ time git grep -w ...... v1.6.1 >/dev/null
real 0m1.611s
user 0m0.000s
sys 0m0.015s
With the patch it's quite a bit faster:
$ time git grep -w ...... v1.6.1 >/dev/null
real 0m1.179s
user 0m0.000s
sys 0m0.015s
More common search patterns will gain a lot less, but it's a nice clean
up anyway.
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx> Signed-off-by: Junio C Hamano <gitster@pobox.com>