Bug#870288: equivs: silently ignores Essential flag

[Adam Borowski]

Package: equivs
Version: 2.1.0
Severity: normal

Hi!
If the control file includes an Essential flag (or not-yet-official
Important), such flags are silently ignored.  I'd expect them to be copied
to the new package, or at least an error or warning.

Beside testing, Essential dummy packages are useful in case when some
package managers insist on removing packages because of an arch:any/all
version mismatch, or even because of a bogus Recommends that conflicts with
an equivs package.  It'd be better to "apt-mark hold" the equivs package,
but handling of holds tends to be buggy.

For example, the following equivs-control (commented-out lines removed):
.----
Section: misc
Priority: optional
Standards-Version: 3.9.2

Package: foo
Essential: yes
Description: test of essential packages
 blah blah
`----

produces a package with:
.----
Package: foo
Version: 1.0
Architecture: all
Maintainer: Adam Borowski <kilobyte at angband.pl>
Installed-Size: 9
Section: misc
Priority: optional
Multi-Arch: foreign
Description: test of essential packages
 blah blah
`----


Meow!
-- System Information:
Debian Release: buster/sid
  APT prefers unstable-debug
  APT policy: (500, 'unstable-debug'), (500, 'unstable'), (500, 'testing'), (150, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.13.0-rc3-debug-00026-g0172821546b5 (SMP w/6 CPU cores)
Locale: LANG=C.UTF-8, LC_CTYPE=C.UTF-8 (charmap=UTF-8), LANGUAGE=C.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)

Versions of packages equivs depends on:
ii  debhelper  10.7
ii  dpkg-dev   1.18.24
ii  fakeroot   1.21-3.1
ii  make       4.1-9.1
ii  perl       5.26.0-4

equivs recommends no packages.

equivs suggests no packages.

-- no debconf information