From a0d095e70735f8237ccfd4b6a7fce35408c08bf1 Mon Sep 17 00:00:00 2001
From: Monster Iestyn <iestynjealous@ntlworld.com>
Date: Tue, 3 Jan 2017 18:47:46 +0000
Subject: [PATCH] Fix sector floordata/ceilingdata/lightingdata pointers not
 being NULL when they should be

This fixes ERCZ's lava falls not moving after joining a netgame at that stage. Possibly explains other various floor/ceiling related netgame quirks that haven't been noticed until now, maybe even in multiplayer levels.
---
 src/p_saveg.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/p_saveg.c b/src/p_saveg.c
index 14386ff1..66fc118a 100644
--- a/src/p_saveg.c
+++ b/src/p_saveg.c
@@ -2607,6 +2607,7 @@ static void P_NetUnArchiveThinkers(void)
 	thinker_t *next;
 	UINT8 tclass;
 	UINT8 restoreNum = false;
+	UINT32 i;
 
 	if (READUINT32(save_p) != ARCHIVEBLOCK_THINKERS)
 		I_Error("Bad $$$.sav at archive block Thinkers");
@@ -2627,6 +2628,12 @@ static void P_NetUnArchiveThinkers(void)
 	iquetail = iquehead = 0;
 	P_InitThinkers();
 
+	// clear sector thinker pointers so they don't point to non-existant thinkers for all of eternity
+	for (i = 0; i < numsectors; i++)
+	{
+		sectors[i].floordata = sectors[i].ceilingdata = sectors[i].lightingdata = NULL;
+	}
+
 	// read in saved thinkers
 	for (;;)
 	{