Subject: Re: bug#22793: grep -E assertion failure with back references

From: [email-masked]
Date: Wed, 24 Feb 2016 23:12:10 -0700

Paul Eggert <[email-masked]> wrote:

> With recent 'grep' you can work around the problem by configuring 
> --with-included-regex.

Not so. I did a fresh

	./boostrap
	./configure --with-included-regex
	make

and it still core dumps:

$ echo abc | ./src/grep -E  '(.*)(.*)(.*)\3\2\1'
grep: regexec.c:1413: pop_fail_stack: Assertion `((Idx) (num) < ((Idx) -2))' failed.
Aborted (core dumped)

I looked at it in a debugger fs->num before the --fs->num executes looks to
be -1.

Thanks,

Arnold