Shlomi Fish <shlomif@shlomifish.org> write:
> `which grep` --color -rP getline grep-test

If -o or --color option is specified, may be line_end < validated in
longest exact match.  As a result, a negative value is set to
`search_bytes'.

I improved validation for input buffer in order to fix the bug.
However, possibly it may cause slowdown.