possible grep bug: -i switch with character class

[Chris Jerdonek]

There seems to be some sort of glitch with character classes and the
-i (--ignore-case) switch.

I am using Mac OS X 10.6.1 (Snow Leopard).

grep --version shows v2.5.1.

I have not checked the latest grep version.  Hopefully you can do that
without too much trouble.

To reproduce--

Create a text file called "test.txt" that consists of a single line of
text with the two letters T and K followed by a unix line feed, as
shown below (also see the attached file):

TK

(I did not attempt to reduce the test case further or see if the
particular choice of letters matters.)

The case-insensitive search "grep -i [A-Z]K test.txt" finds no matches
while the same search done case-sensitively (i.e. without the -i
switch) does find a match.  See below for a console session that shows
a couple other related searches that work.

$ grep [A-Z]K test.txt
TK
$ grep [T]K test.txt
TK
$ grep -i [T]K test.txt
TK
$ grep -i [^A-Z]K test.txt
TK
$ grep -i [A-Z]K test.txt
$

I will also attempt to report this here:

http://savannah.gnu.org/projects/grep/

Thanks,
--Chris

test.txt
Description: Text document