Bug#998115: lintian: false positive: "unknown-field Description" in source package

[Hannah Rittich <void@rittich.net>]

Package: lintian
Version: 2.110.0
Severity: normal
X-Debbugs-Cc: void@rittich.net

Adding a "Description" field in the source section of a control file
will cause lintian to issue the error "source: unknown-field Description".

The Debian Policy Manual [1] states that "in a source or binary control
file, the Description field contains a description of the binary package
[...]". Furthermore, deb-substvars allows to reference the description
field of the source package, using the variables ${source:Synopsis} and
${source:Extended-Description} [2]. Hence, adding a description to a
source package should be allowed. This field can be used to avoid
repetitions in the control file, as done by the abseil package [3],
which displays the said error message [4].

I would suggest to remove this warning for the "Description" field in
the source section.

[1]: 
https://www.debian.org/doc/debian-policy/ch-controlfields.html#s-f-description
[2]: 
https://manpages.debian.org/bullseye/dpkg-dev/deb-substvars.5.en.html#source:Synopsis
[3]: https://sources.debian.org/src/abseil/0~20200923.3-3/debian/control/
[4]: https://lintian.debian.org/sources/abseil