Your bug report

#18750: --line-buffered option doesn't work with --files-with-matches

which was filed against the grep package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to 18750@debbugs.gnu.org.

-- 
18750: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=18750
GNU Bug Tracking System
Contact help-debbugs@gnu.org with problems