HSQLDB / Unit tests

Hi all,

I'm trying to get HSQLDB unit tests to run in a CppunitTest -- whilst
still in solver I added some paths locally to solver's unorc (which
worked fine, but not a great solution) -- now that we're running unit
tests in instdir I'd like some sort of permanent solution. (The reason I
want to use a CppUnitTest is that ideally we want to run exactly the
same tests on Firebird and HSQLDB, and since that also allows for
performance comparisons.)

HSQLDB's classpath is hardcoded in HDriver.cxx as:
vnd.sun.star.expand:$BRAND_BASE_DIR/" LIBO_SHARE_JAVA_FOLDER
"/hsqldb.jar"
As a first step I'd like to make this:
vnd.sun.star.expand:$LO_JAVA_DIR/hsqldb.jar

Either of these work when running LO normally, the latter is cleaner and
seems much more correct. (Patch is in gerrit, but outdated commit
comment now that we're in instdir --
https://gerrit.libreoffice.org/#/c/5953/ ).

However neither of these work for unit tests: BRAND_BASE_DIR and
LO_JAVA_DIR are both set in fundamentalrc, which doesn't seem to be used
when running unit tests. It also looks like when running unit tests only
the ure/lib/unorc is used -- I'm not entirely sure how to procede here
-- using LO_JAVA_DIR within HSQLDB setting 
LO_JAVA_DIR=${ORIGIN}/../../program/classes
works, but is that the desired way of doing things (adjusted by using
scp2 I guess to work on all systems)?

Cheers,
        Andrzej