From 82255c4dfd0a7a8bcc92cda6958f4d951147157b Mon Sep 17 00:00:00 2001
From: John Palomo Jr <palomo.john@hotmail.com>
Date: Sun, 19 Oct 2014 20:52:48 -0400
Subject: [PATCH] Using PickActor will only set the TID if the picked actor
 doesn't have a TID already. An optional 8th parameter (bool forceTID) was
 added to revert to the old behavior.

---
 src/p_acs.cpp | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/src/p_acs.cpp b/src/p_acs.cpp
index bc4cbdb758..aeb47a8075 100644
--- a/src/p_acs.cpp
+++ b/src/p_acs.cpp
@@ -5619,15 +5619,27 @@ doplaysound:			if (funcIndex == ACSF_PlayActorSound)
 					wallMask = args[6];
 				}
 
+				bool forceTID = 0;
+				if (argCount >= 8)
+				{
+					if (args[7] != 0)
+						forceTID = 1;
+				}
+
 				AActor* pickedActor = P_LinePickActor(actor, args[1] << 16, args[3], args[2] << 16, actorMask, wallMask);
 				if (pickedActor == NULL) {
 					return 0;
 				}
 
-				pickedActor->RemoveFromHash();
-				pickedActor->tid = args[4];
-				pickedActor->AddToHash();
-				
+				if (!(forceTID) && (args[4] == 0) && (pickedActor->tid == 0))
+					return 0;
+
+				if ((pickedActor->tid == 0) || (forceTID))
+				{
+					pickedActor->RemoveFromHash();
+					pickedActor->tid = args[4];
+					pickedActor->AddToHash();
+				}
 				return 1;
 			}
 			break;