I would say about 680,000 lines - just did a fresh download from sourceforge
and did
cd ~/src/genocad/zend
cat `find . -type f | grep -v docs|grep -v tests|grep -v jpg|grep -v svn|grep -v png|grep -v images|grep -v -i test`|wc -l
which returns
more generously, if I do a
cd ~/src/genocad
cat `find . -type f `|wc -l
I'm seeing over 1.5 million lines !