- Added Blzut3's noextratic fix.

SVN r4231 (trunk)

src/p_mobj.cpp

@@ -3498,10 +3498,15 @@ void AActor::Tick ()
 	// cycle through states, calling action functions at transitions
 	if (tics != -1)
 	{
-		tics--;
-				
 		// you can cycle through multiple states in a tic
-		// [RH] Use <= 0 instead of == 0 so that spawnstates
+		// [BL] If we reach here with a 0 duration state, we
+		// have created an extra tic, so account for it.
+		int newtics;
+		do
+		{
+			newtics = --tics;
+
+			// [RH] Use tics <= 0 instead of == 0 so that spawnstates
 			// of 0 tics work as expected.
 			if (tics <= 0)
 			{
@@ -3515,6 +3520,8 @@ void AActor::Tick ()
 					return; 		// freed itself
 			}
 		}
+		while (newtics < 0);
+	}
 	else
 	{
 		int respawn_monsters = G_SkillProperty(SKILLP_Respawn);