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User-Agent: Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0)

Description of problem:
When I use regular expression in grep, it outputs lines which do not contain 
the specified patterns.

Version-Release number of selected component (if applicable):


How reproducible:
Always

Steps to Reproduce:
Just try the following at shell prompt:
echo "foo" |grep "[L-Z]"


Actual Results:  foo

Expected Results:  nothing should be output

Additional info:

At first, I thought it was a case-sensitivity problem, but later I found more 
problems. Note that in the above example, letter 'f' is not even in the list [l-
z]. grep is being constantly used by many scripts and programs, and this bug 
leads to a potential security breach.