Bug#947844: libservlet3.1-java: 8.5.50-0+deb9u1 breaks upgrades to Buster

[Colomban Wendling]

Package: libservlet3.1-java
Version: 8.5.50-0+deb9u1
Severity: important

Dear Maintainer,

Since upload of version 8.5.50-0+deb9u1, upgrades to Buster are broken:

Unpacking libel-api-java (3.0.0-2) ...
dpkg: error processing archive /tmp/apt-dpkg-install-pjjAYg/328-libel-api-java_3.0.0-2_all.deb (--unpack):
 trying to overwrite '/usr/share/maven-repo/javax/el/javax.el-api/3.0/javax.el-api-3.0.pom', which is also in package libservlet3.1-java 8.5.50-0+deb9u1
[…]
Unpacking libjsp-api-java (2.3.4-2) ...
dpkg: error processing archive /tmp/apt-dpkg-install-pjjAYg/362-libjsp-api-java_2.3.4-2_all.deb (--unpack):
 trying to overwrite '/usr/share/maven-repo/javax/servlet/jsp/javax.servlet.jsp-api/2.3/javax.servlet.jsp-api-2.3.pom', which is also in package libservlet3.1-java 8.5.50-0+deb9u1
[…]
Unpacking libwebsocket-api-java (1.1-1) ...
dpkg: error processing archive /tmp/apt-dpkg-install-pjjAYg/388-libwebsocket-api-java_1.1-1_all.deb (--unpack):
 trying to overwrite '/usr/share/maven-repo/javax/websocket/javax.websocket-api/1.0/javax.websocket-api-1.0.pom', which is also in package libservlet3.1-java 8.5.50-0+deb9u1

The reason seems to be that files from this package migrated to other
packages in Buster, but at an earlier version than 8.5.50-0+deb9u1
(looks like the move happenend in 8.5.35-3~, according to the Breaks
in the now-broken packages).

I am not sure how this can be solved short of splitting the packages
the same way as in Buster, or possibly providing a newer version in
Buster with updated version in Breaks fields, if that works also for
people updating from earlier versions.

Regards,
Colomban

-- System Information:
Debian Release: 9.11
  APT prefers oldstable-updates
  APT policy: (500, 'oldstable-updates'), (500, 'oldstable')
Architecture: amd64 (x86_64)

Kernel: Linux 4.9.0-11-amd64 (SMP w/2 CPU cores)
Locale: LANG=fr_FR.UTF-8, LC_CTYPE=fr_FR.UTF-8 (charmap=UTF-8), LANGUAGE=fr_FR.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

-- no debconf information