Bug#911341: libedit2:amd64.symbols is missing -debianversion in version numbers and hence dysfunctional

[Christoph Berg]

Source: libedit
Version: 3.1-20180525-1
Severity: serious

Hi,

IRC user ikcalB just reported missing "append_history" symbol in
/usr/lib/postgresql/10/bin/psql when installing postgresql-10 from
buster on stretch. The problem goes away when libedit2 is upgraded to
the buster version.

$ apt-cache show postgresql-client-10
Package: postgresql-client-10
Version: 10.5-1
Architecture: amd64
Depends: libedit2 (>= 3.1-20180525) [...]

$ apt-cache policy libedit2
libedit2:
  Installiert:           3.1-20160903-3
  Installationskandidat: 3.1-20180525-1
  Versionstabelle:
     3.1-20180525-1 500
        500 http://deb.debian.org/debian buster/main amd64 Packages
 *** 3.1-20160903-3 100
        100 /var/lib/dpkg/status

Note that dpkg/apt think that the dependency is fulfilled.

$ dpkg --compare-versions 3.1-20160903-3 gt 3.1-20180525 && echo greater
greater

The problem is that when comparing version numbers, dpkg strips the
last -debianversion component, so the real comparison here is

3.1-20160903 (Debian 3) >= 3.1 (Debian 20180525)

Ugh.

I think for packages with an extra dash in the version number, the
general rule should be not to omit the -debianversion part in the
.shlib and .symbols files. (I guess lintian could check that.)

Christoph