gnu/105221: grep(1): `grep -w -F ""` issue

[martinko]

>Number:         105221
>Category:       gnu
>Synopsis:       grep(1): `grep -w -F ""` issue
>Confidential:   no
>Severity:       serious
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Nov 06 20:00:41 GMT 2006
>Closed-Date:
>Last-Modified:
>Originator:     martinko
>Release:        FreeBSD 6.2-PRERELEASE
>Organization:
>Environment:
FreeBSD mb-aw1n-bsd 6.2-PRERELEASE FreeBSD 6.2-PRERELEASE #0: Sat Sep 23 10:05:07 CEST 2006     root at mb-aw1n-bsd:/usr/obj/usr/src/sys/MB-AW1N  i386
>Description:
after running the following command grep(1) starts eating all available cpu and won't finish:
$ echo qaz | grep -w -F ""
>How-To-Repeat:
just run the following from your shell:
echo qaz | grep -w -F ""
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: