Improvements to blaze and ghast (#4547)

src/MobSpawner.cpp

@@ -123,7 +123,6 @@ bool cMobSpawner::CanSpawnHere(cChunk * a_Chunk, Vector3i a_RelPos, eMonsterType
 		}
 
 		case mtBlaze:
-		case mtGhast:
 		{
 			return (
 				(targetBlock == E_BLOCK_AIR) &&
@@ -194,6 +193,15 @@ bool cMobSpawner::CanSpawnHere(cChunk * a_Chunk, Vector3i a_RelPos, eMonsterType
 			break;
 		}
 
+		case mtGhast:
+		{
+			return (
+				(targetBlock == E_BLOCK_AIR) &&
+				(blockAbove == E_BLOCK_AIR) &&
+				(random.RandBool())
+			);
+		}
+
 		case mtGuardian:
 		{
 			return (