On backporting fix for tdf#124503 "LibreOffice doesn't detect JVM because of unexpected java.vendor property value"

[Stephan Bergmann]

See <https://bugs.documentfoundation.org/show_bug.cgi?id=124503#c9> for 
the fix for master (towards LO 6.3).  While the title and fix both cover 
a broad scope (any JRE that reports a java.vendor that the LO code 
doesn't find in its hardcoded list), the issue that prompted the bug and 
the fix is that Debian and Ubuntu apparently started to distribute 
OpenJDK versions that no longer announce the well-known Oracle 
java.vendor string, but instead go with things like "Debian", "Ubuntu", 
or "Private".

It is not clear to me whether those distros will revert their 
modifications soonish (so that there would be no immediate need for LO 
to get anything fixed on our side).  If not, the question is whether to 
backport the above fix to libreoffice-6-1 (towards LO 6.1.6), 
libreoffice-6-2 (towards LO 6.2.4), and maybe even libreoffice-6-2-3. 
The fix isn't exactly small, so I would prefer to not backport it 
aggressively.  But I don't know how severely users would be affected by 
this issue.  (I assume that Debian and Ubuntu would take care of the 
issue for their bundled LO, by updating the hard-coded list accordingly. 
  That could also be an alternative to backporting the above fix here at 
upstream, but with drawbacks:  We would---somewhat needlessly---extend 
the hardcoded list, even if master already has a fix that makes the 
additions moot.)

Thoughts, esp. from people involved in the relevant distros?