bug#17640: grep with -m reads the entire input

[Paul Eggert]

> With grep 2.18, the -m option would cause grep to stop reading input
> after printing the requested number of matching lines.  With version
> 2.19, grep reads the entire input before exiting.

Can you give an example of the failure?  What platform are you running 
on?  I couldn't reproduce the problem on Fedora 20 x86-64.  Here's how I 
tried:

$ seq 1000000 >million
$ (grep -m1000 0 | wc -l; wc -l) <million
1000
995994

and these numbers look correct to me.