Bug#951896: reportbug: Using back button breaks interface

[Philipp Klaus Krause <pkk@spth.de>]

Package: reportbug
Version: 7.6.0
Severity: important

Whenever I click the back button ("Zurück" in my locale), all elements except
for the cancel, back and forward buttons become greyed out. This is true for
the current page and all previously seen pages. Sometimes even the forward
button turns grey. Thus e.g. when choosing to invoke a mail agent to "Choose a
mailer for your report", from the moment I press the back button on that page
(because my favorite mail agent, thunderbird is not in the list), reportbug
becomes unuseable, and I have to canvel and re-invoke reportbug, and put in all
the info again.



-- Package-specific info:
** Environment settings:
INTERFACE="gtk"

** /home/philipp/.reportbugrc:
reportbug_version "7.5.0"
mode advanced
ui gtk2
email "pkk@spth.de"
no-cc
header "X-Debbugs-CC: pkk@spth.de"
smtphost reportbug.debian.org

-- System Information:
Debian Release: bullseye/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'testing'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.4.0-3-amd64 (SMP w/4 CPU cores)
Locale: LANG=de_DE.utf8, LC_CTYPE=de_DE.utf8 (charmap=UTF-8), LANGUAGE=de_DE.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages reportbug depends on:
ii  apt                1.8.4
ii  python3            3.7.5-3
ii  python3-reportbug  7.6.0
ii  sensible-utils     0.0.12+nmu1

reportbug recommends no packages.

Versions of packages reportbug suggests:
pn  claws-mail                                 <none>
pn  debconf-utils                              <none>
pn  debsums                                    <none>
pn  dlocate                                    <none>
ii  emacs-bin-common                           1:26.3+1-1
ii  exim4-daemon-light [mail-transport-agent]  4.93-10
ii  file                                       1:5.38-4
ii  gnupg                                      2.2.19-1
pn  python3-urwid                              <none>
ii  reportbug-gtk                              7.6.0
ii  xdg-utils                                  1.1.3-1

Versions of packages python3-reportbug depends on:
ii  apt                1.8.4
ii  file               1:5.38-4
ii  python3            3.7.5-3
ii  python3-apt        1.8.5
ii  python3-debian     0.1.36
ii  python3-debianbts  3.0.2
ii  python3-requests   2.22.0-2
ii  sensible-utils     0.0.12+nmu1

python3-reportbug suggests no packages.

-- no debconf information