Bug#917256: gnuplot-qt: should provide gnuplot-x11 in order to avoid conflicting dependencies

[Vincent Lefevre]

Package: gnuplot-qt
Version: 5.2.5+dfsg1-1
Severity: important

If I understand correctly, gnuplot-qt is like gnuplot-x11, but also
has Qt support. Thus it should provide gnuplot-x11 in order to satisfy
some dependencies.

As an example, if I want to install maxima, apt wants to remove
gnuplot-qt and replace it by gnuplot-x11, thus losing Qt support:

# apt install maxima
[...]
The following additional packages will be installed:
  gnuplot-x11 maxima-share
Suggested packages:
  texmacs maxima-doc xmaxima maxima-emacs
The following packages will be REMOVED:
  gnuplot-qt gnuplot-qt-dbgsym
The following NEW packages will be installed:
  gnuplot-x11 maxima maxima-share

The reason is that maxima recommends gnuplot-x11.

-- System Information:
Debian Release: buster/sid
  APT prefers unstable-debug
  APT policy: (500, 'unstable-debug'), (500, 'stable-updates'), (500, 'unstable'), (500, 'testing'), (500, 'stable'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 4.19.0-1-amd64 (SMP w/8 CPU cores)
Locale: LANG=POSIX, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=POSIX (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages gnuplot-qt depends on:
ii  gnuplot-data         5.2.5+dfsg1-1
ii  libc6                2.28-3
ii  libcairo2            1.14.10-1
ii  libedit2             3.1-20181209-1
ii  libgcc1              1:8.2.0-13
ii  libgd3               2.2.5-5
ii  libglib2.0-0         2.58.1-2
ii  liblua5.3-0          5.3.3-1
ii  libpango-1.0-0       1.42.1-1
ii  libpangocairo-1.0-0  1.42.1-1
ii  libqt5core5a         5.11.1+dfsg-6
ii  libqt5gui5           5.11.1+dfsg-6
ii  libqt5network5       5.11.1+dfsg-6
ii  libqt5printsupport5  5.11.1+dfsg-6
ii  libqt5svg5           5.11.1-2
ii  libqt5widgets5       5.11.1+dfsg-6
ii  libstdc++6           8.2.0-13
ii  libwxbase3.0-0v5     3.0.4+dfsg-7
ii  libwxgtk3.0-0v5      3.0.4+dfsg-7
ii  libx11-6             2:1.6.7-1

gnuplot-qt recommends no packages.

Versions of packages gnuplot-qt suggests:
ii  gnuplot-doc  5.2.5+dfsg1-1

-- no debconf information