Incorrect configuration of %_sharedstatedir in rpmbuild

[Andreas Scherer]

Description: Ubuntu 18.04.2 LTS
Release: 18.04

rpm:
  Installiert: 4.14.1+dfsg1-2
  Installationskandidat: 4.14.1+dfsg1-2
  Versionstabelle:
 *** 4.14.1+dfsg1-2 500
        500 http://de.archive.ubuntu.com/ubuntu bionic/universe amd64 Packages
        100 /var/lib/dpkg/status

Executed commands: $> rpmbuild -E %_localstatedir
                   $> rpmbuild -E %_sharedstatedir

Expected results: /var
                  /var/lib

Actual results: /var
                /usr/com

Rationale: Although the GNU Coding Standards proclaim that 'localstatedir' should always be set to '$(prefix)/var' and 'sharedstatedir' should always be set to '$(prefix)/com', RPM overrides 'localstatedir' in 'platform.in' to '/var'. It would be very useful (and in accordance with other Linux distributions like Fedora) to replace 'sharedstatedir' with a more familiar value '/var/lib'. Unfortunately, this has to be triggered manually at compile-time of the RPM sources with './configure --sharedstatedir=/var/lib'.