grep version 2.5.3 and 2.5.4 bug with case-insensitive (-i) matching POSIX pattern class [[:upper:]]

[Roman Revyakin]

Hi,

There seems to be a bug in grep versions 2.5.3 and 2.5.4 executing
this sample piece of code:

echo "(A)" | grep -i "([[:upper:]])"

produces no output. grep version 2.5.1 works fine though:

echo "(A)" | grep -i "([[:upper:]])"
(A)

I compiled greps 2.5.3 and 2.5.1 on the Slackware 13 box from the
archives taken from

http://ftp.gnu.org/gnu/grep/

The grep 2.5.4 was shipped with the Slackware 13 itself.

Thanks in advance!

Regards,
Roman