This is a bug I introduced while merging Philipp's patch.
* spot/misc/game.cc (parity_game::solve): Set the strategy for player
0 in useless SCCs.
(parity_game::fix_scc): Do not use sub_game_ to detect edges exiting
the SCC.
* tests/python/game.py: New file.
* tests/Makefile.am: Add it.
