// In the room (644) connected to the lower door of the bat-infested stairway,
// peering through the keyhole *always* reports bats.
//
// As you kill the bats, global plot flags are set. Normally flags 331-334
// would be checked via proc0_4(). They're in a bitmask, among other flags, so
// we can check all simultaneously (0000000000011110).
//
// global[520] & 30 == 30
//
// Room 644 has an IF-ELSE deciding between largely redundant calls to
// gloryMessager::say(). We make room by combining them.

// In the crest bookshelf room (663) connected to the upper door of the
// bat-infested stairway, peering through the keyhole *always* reports bats.
//
// As you kill the bats, global plot flags are set. Normally flags 331-334
// would be checked via proc0_4(). They're in a bitmask, among other flags, so
// we can check all simultaneously (0000000000011110).
//
// global[520] & 30 == 30
//
// Patch 1: There was no space for this in the responsible method. Instead, we
//  rewrite a different method that became obsolete after the crest bookshelf
//  patch: sCloseSecretDoor::changeState().
//
// Patch 2: We modify sPeepingTom to call our rewritten sCloseSecretDoor. This
//  has two variants, toggled to match the detected edition with enablePatch()
//  below. Aside from the patched lofsa value, they are identical.
//
// Requires patch: qfg4CrestBookshelf (CD or Floppy)