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

[arnold]

Paul Eggert <address@hidden> 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