bash-completion script prevent direxpand to be effective

I am submitting after verifying it is really a bug by asking a question in askubuntu: https://askubuntu.com/questions/1010931/direxpand-unexpected-behavior

With the default bash, bash option `direxpand` is unset by default:

    shopt direxpand
    direxpand off

So normally when I type:

    proc=/proc
    ls $proc/<tab>

I should see no expansion, but I see

    ls /proc/

After investigation it is the bash-completion script which overide direxpand. I do not know if this could be avoided...

version: Ubuntu 16.04.3 LTS

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: bash 4.3-14ubuntu1.2
ProcVersionSignature: Ubuntu 4.10.0-28.32~16.04.2-generic 4.10.17
Uname: Linux 4.10.0-28-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.10
Architecture: amd64
CurrentDesktop: Unity
Date: Fri Mar 2 06:08:05 2018
ExecutablePath: /bin/bash
InstallationDate: Installed on 2017-08-04 (209 days ago)
InstallationMedia: Ubuntu 16.04.3 LTS "Xenial Xerus" - Release amd64 (20170801)
SourcePackage: bash
UpgradeStatus: No upgrade log present (probably fresh install)