non-NULL doesn't force the return value to be true.
git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@5631 c06c8d41-db1a-0410-9941-cceddc491573
MDR5DQBWC2BYHXQXL2S5DCWED4ZOXLGBN3EC4KJL3SN6KZ6P3ONAC
D2T32ZGFCJFZVJW7H2AEV3QD7Z4ZYKWEPOZTAFTAPDUTBGXNJXNAC
YZXHBEKWQPY4BTKG5FFGLP3AIRBQSTKQVLJJHWKQEA3HTN4UHDYQC
K2CS6TCX2NDVL2ASEHGP4J4K4IJ6FP3ANNKTSIWVG43HPYSBX6ZQC
ASSERT (holy || unholy || antimagical);