egrep bug

[Bob Greiner]

Version 2.4.2 of egrep does not seem to work as expected. When I execute the 
command

   egrep "^[a-z]" data.txt
   
on the attached sample file, egrep does not display only those records 
beginning with lower case letters. 

Similarly,

   egrep "^[A-Z]" data.txt
   
does not return just those records beginning with upper case letters.

Fortunately, I was able to do what I wanted to do by using the posix constructs 
[:upper:] and [:lower:] that worked just fine.

I managed to dig out an old copy of egrep version 2.3, and it works as expected.

Is this change to version 2.4.2 an oversight or a deliberate modification?

data.txt
Description: Binary data