Addresses issue #3009 .  gh_bounded_17 test previously failed in dbg mode due to a division by zero since there was zero gas present, so a mass balance for gas did not make sense
Merge pull request #3010 from WilkAndy/feature_3009

Addresses issue #3009 .  gh_bounded_17 test previously failed in dbg mod...
Merge commit '673fedc267ba933f96f39a669971d1327ed902cf'