Allow summoning/recalling fliers over deep water

The routine which finds free space to place these monsters now uses
monster_habitable_grid directly instead of its own logic (which ignored
flying entirely).

Spells which can summon both fliers and non-fliers (ie: call imp,
summon greater demon, etc.) will make no attempt to respect the surrounding
terrain when choosing a monster type (and so will sometimes attempt to
summon a monster that cannot be placed at that terrain, and fail as
previously), though it is arguably better if players cannot influence what
things they summon by where they are standing. In either case, this is
certainly much better than Haunt and Battlesphere failing when over deep
water for no clear reason.

1 files changed, 2 insertions, 2 deletions

diff --git a/crawl-ref/source/mon-place.h b/crawl-ref/source/mon-place.h
index 18219ee473..a40e5aaa8d 100644
--- a/crawl-ref/source/mon-place.h
+++ b/crawl-ref/source/mon-place.h
@@ -64,8 +64,8 @@ conduct_type player_will_anger_monster(monster_type type);
 conduct_type player_will_anger_monster(monster* mon);
 bool player_angers_monster(monster* mon);
 
-bool empty_surrounds(const coord_def& where, dungeon_feature_type spc_wanted,
-                      int radius, bool allow_centre, coord_def& empty);
+bool find_habitable_spot_near(const coord_def& where, monster_type mon_type,
+                              int radius, bool allow_centre, coord_def& empty);
 
 monster_type summon_any_demon(monster_type dct);