bug#36367: Potential bug in grep / egrep

[Henrik Holst]

I expected these two commands to produce the exact same result:

holst@hholst-lt:~$ egrep -l '^(telegram-desktop)$' /proc/*/cmdline
/proc/20596/cmdline
holst@hholst-lt:~$ egrep -x -l 'telegram-desktop' /proc/*/cmdline
/proc/20596/cmdline
/proc/self/cmdline
/proc/thread-self/cmdline
holst@hholst-lt:~$ 

Version:

holst@hholst-lt:~$ egrep --version
grep (GNU grep) 3.3
Copyright (C) 2018 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by Mike Haertel and others; see
<https://git.sv.gnu.org/cgit/grep.git/tree/AUTHORS>.
holst@hholst-lt:~$ cat /etc/lsb-release 
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=19.04
DISTRIB_CODENAME=disco
DISTRIB_DESCRIPTION="Ubuntu 19.04"
holst@hholst-lt:~$