dpkg-dev: dpkg-scan{packag,sourc}es fail when symlinks exist

[Steve M.]

This is the same bug reported in the Debian Bug report logs, #809219, against dpkg-dev 1.18.4:

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=809219

It can be reproduced using the same x.tgz file found in the original Debian #809219 bug report. I have attached it here for reference.

To reproduce:

$ tar xfz x.tgz
$ dpkg-scanpackages .

The expected result is no error. The actual result is a failure with the following output emitted:

/tmp/x/dists/sid/wtf/binary-all encountered a second time at /usr/share/perl/5.22/File/Find.pm line 103.

Ubuntu Version:
Description: Ubuntu 16.04.1 LTS
Release: 16.04

dpkg-dev Package Version: 1.18.4ubuntu1.2

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: dpkg-dev 1.18.4ubuntu1.2
ProcVersionSignature: Ubuntu 4.4.0-70.91-generic 4.4.49
Uname: Linux 4.4.0-70-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.5
Architecture: amd64
CurrentDesktop: Unity
Date: Mon May 1 09:51:41 2017
InstallationDate: Installed on 2016-12-13 (138 days ago)
InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_US
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: dpkg
UpgradeStatus: No upgrade log present (probably fresh install)

[Steve M. (digitalgoo)]

Fix is here: https://anonscm.debian.org/cgit/dpkg/dpkg.git/diff/?id=6ca0dfd