grep bug report: --only-matching fails

[address@hidden]

When trying to match a repeated character class, the match works when
using grep with no arguments, but the match fails when using -o (show
only the matching pattern).  I've attached grepbug-cli.txt, which
demonstrates the bug, and the input file I used,
grepbug-onlymatching.txt.  I even tried throwing on perl support with
-P, because I know character classes are defined in this way with Perl
regular expressions.  Also, adding quotes around the match pattern
makes no difference.

Thanks.

grepbug-cli.txt
Description: Text document

grepbug-onlymatching.txt
Description: Text document