Description of problem:
grep doesn't seems to like special charachers when using Perl regex if the enviroment uses UTF-8.

$ echo $LANG
it_IT.UTF-8
$ if [ -z $LC_ALL ]; then echo Variable \$LC_ALL not set; fi
Variable $LC_ALL not set
$ echo à | grep -P "[0-9]*"
Annullato (core dumped)
$ export LC_ALL=$LANG; echo à | grep -P "[0-9]*"; unset LC_ALL
Annullato (core dumped)
$ export LC_ALL=it_IT.UTF-8; echo à | grep -P "[0-9]*"; unset LC_ALL
Annullato (core dumped)
$ export LC_ALL=it_IT; echo à | grep -P "[0-9]*"; unset LC_ALL
à
$ export LC_ALL=en_US.UTF-8; echo à | grep -P "[0-9]*"; unset LC_ALL
Aborted (core dumped)
$ export LC_ALL=en_US; echo à | grep -P "[0-9]*"; unset LC_ALL
à
$ export LC_ALL=C; echo à | grep -P "[0-9]*"; unset LC_ALL
à

Version-Release number of selected component:
grep-2.15-1.fc20

Additional info:
reporter:       libreport-2.1.10
backtrace_rating: 4
cmdline:        grep --color=auto -P [0-9]*
crash_function: Pexecute
executable:     /usr/bin/grep
kernel:         3.12.5-302.fc20.x86_64
runlevel:       N 5
type:           CCpp
uid:            1000

Truncated backtrace:
Thread no. 1 (7 frames)
 #2 Pexecute at pcresearch.c:189
 #3 print_line_middle at main.c:835
 #4 prline at main.c:937
 #5 prtext at main.c:1043
 #6 grepbuf at main.c:1113
 #7 grep at main.c:1214
 #8 grepdesc at main.c:1467