mapnik/mapnik — comment on commit 2fadf1f2d333f6f4d472c9510bc70f261c4e7fab
File: include/mapnik/ctrans.hpp line 83
By artemp:

@springmeyer - well spotted, i can also see there might be an issue with passing not-zero initialised 'z' in :
ok = prj_trans_.backward(*x, *y, z);

FIXME