Creating a new filter can corrupt existing filters

[Paul White]

When creating a new filter existing filters might be corrupted depending on how a new filter is created.

Steps to reproduce:

1. Bring up Filters dialog
2. Click on "New"
3. Set required options
4. Click OK to close dialog

Expected outcome:

New filter created and existing filters untouched

Actual outcome:

New filter created but existing filters are corrupted

Workaround:

When creating a new filter first select one or more existing filters before clicking on "New". The default filters can be restored by deleting file "/root/.synaptic/filters"

Confirmation of the bug:

https://ubuntu-mate.community/t/synaptics-custom-filter-corruption-workaround/13965

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: synaptic 0.84.3ubuntu1
ProcVersionSignature: Ubuntu 4.15.0-33.36-generic 4.15.18
Uname: Linux 4.15.0-33-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.2
Architecture: amd64
CurrentDesktop: communitheme:ubuntu:GNOME
Date: Fri Aug 31 10:01:06 2018
InstallationDate: Installed on 2018-08-15 (15 days ago)
InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725)
SourcePackage: synaptic
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.