From ab837b608d2ad3dba4f9be2a1749a53f8048d0c9 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <c.oelckers@zdoom.fake>
Date: Sun, 7 Aug 2016 22:03:36 +0200
Subject: [PATCH] - compatibility optioned triggering sector actions by
 indirectly initiated teleports

There's several old maps depending on this not happening.

- Set the option for Hell's Twisted Influence Part 1.
---
 src/compatibility.cpp           | 1 +
 src/d_main.cpp                  | 3 ++-
 src/doomdef.h                   | 1 +
 src/g_mapinfo.cpp               | 1 +
 src/p_map.cpp                   | 3 ++-
 wadsrc/static/compatibility.txt | 5 +++++
 6 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/compatibility.cpp b/src/compatibility.cpp
index ae3b905d0..870d2ede6 100644
--- a/src/compatibility.cpp
+++ b/src/compatibility.cpp
@@ -147,6 +147,7 @@ static FCompatOption Options[] =
 	{ "soundcutoff",			COMPATF2_SOUNDCUTOFF, SLOT_COMPAT2 },
 	{ "pointonline",			COMPATF2_POINTONLINE, SLOT_COMPAT2 },
 	{ "multiexit",				COMPATF2_MULTIEXIT, SLOT_COMPAT2 },
+	{ "teleport",				COMPATF2_TELEPORT, SLOT_COMPAT2 },
 
 	{ NULL, 0, 0 }
 };
diff --git a/src/d_main.cpp b/src/d_main.cpp
index d6d53dd77..4e360a38e 100644
--- a/src/d_main.cpp
+++ b/src/d_main.cpp
@@ -574,7 +574,7 @@ CUSTOM_CVAR(Int, compatmode, 0, CVAR_ARCHIVE|CVAR_NOINITCALL)
 
 	case 4: // Old ZDoom compat mode
 		v = COMPATF_SOUNDTARGET | COMPATF_LIGHT;
-		w = COMPATF2_MULTIEXIT;
+		w = COMPATF2_MULTIEXIT | COMPATF2_TELEPORT;
 		break;
 
 	case 5: // MBF compat mode
@@ -630,6 +630,7 @@ CVAR (Flag, compat_floormove,			compatflags2, COMPATF2_FLOORMOVE);
 CVAR (Flag, compat_soundcutoff,			compatflags2, COMPATF2_SOUNDCUTOFF);
 CVAR (Flag, compat_pointonline,			compatflags2, COMPATF2_POINTONLINE);
 CVAR (Flag, compat_multiexit,			compatflags2, COMPATF2_MULTIEXIT);
+CVAR (Flag, compat_teleport,			compatflags2, COMPATF2_TELEPORT);
 
 //==========================================================================
 //
diff --git a/src/doomdef.h b/src/doomdef.h
index 56b69fe7c..9ebe45cf7 100644
--- a/src/doomdef.h
+++ b/src/doomdef.h
@@ -342,6 +342,7 @@ enum : unsigned int
 	COMPATF2_SOUNDCUTOFF	= 1 << 2,	// Cut off sounds when an actor vanishes instead of making it owner-less
 	COMPATF2_POINTONLINE	= 1 << 3,	// Use original but buggy P_PointOnLineSide() and P_PointOnDivlineSideCompat()
 	COMPATF2_MULTIEXIT		= 1 << 4,	// Level exit can be triggered multiple times (required by Daedalus's travel tubes, thanks to a faulty script)
+	COMPATF2_TELEPORT		 = 1 << 5,	// Don't let indirect teleports trigger sector actions
 };
 
 // Emulate old bugs for select maps. These are not exposed by a cvar
diff --git a/src/g_mapinfo.cpp b/src/g_mapinfo.cpp
index 78ba9142b..7d3df69e0 100644
--- a/src/g_mapinfo.cpp
+++ b/src/g_mapinfo.cpp
@@ -1341,6 +1341,7 @@ MapFlagHandlers[] =
 	{ "compat_soundcutoff",				MITYPE_COMPATFLAG, 0, COMPATF2_SOUNDCUTOFF },
 	{ "compat_pointonline",				MITYPE_COMPATFLAG, 0, COMPATF2_POINTONLINE },
 	{ "compat_multiexit",				MITYPE_COMPATFLAG, 0, COMPATF2_MULTIEXIT },
+	{ "compat_teleport",				MITYPE_COMPATFLAG, 0, COMPATF2_TELEPORT },
 	{ "cd_start_track",					MITYPE_EATNEXT,	0, 0 },
 	{ "cd_end1_track",					MITYPE_EATNEXT,	0, 0 },
 	{ "cd_end2_track",					MITYPE_EATNEXT,	0, 0 },
diff --git a/src/p_map.cpp b/src/p_map.cpp
index 110ae5235..e7aceba78 100644
--- a/src/p_map.cpp
+++ b/src/p_map.cpp
@@ -434,7 +434,8 @@ bool	P_TeleportMove(AActor* thing, const DVector3 &pos, bool telefrag, bool modi
 
 		// If this teleport was caused by a move, P_TryMove() will handle the
 		// sector transition messages better than we can here.
-		if (!(thing->flags6 & MF6_INTRYMOVE))
+		// This needs to be compatibility optioned because some older maps exploited this missing feature.
+		if (!(thing->flags6 & MF6_INTRYMOVE) && !(i_compatflags2 & COMPATF2_TELEPORT))
 		{
 			thing->CheckSectorTransition(oldsec);
 		}
diff --git a/wadsrc/static/compatibility.txt b/wadsrc/static/compatibility.txt
index a2c3794ae..25395dad6 100644
--- a/wadsrc/static/compatibility.txt
+++ b/wadsrc/static/compatibility.txt
@@ -430,6 +430,11 @@ C98F79709BD7E0E4C19026AB9575EC6F // cc-cod.zip:codlev.wad map07
 	maskedmidtex
 }
 
+7B82B12A6990E09553B12FDB4E3824A0 // hti.wad map01
+{
+	teleport
+}
+
 D7F6E9F08C39A17026349A04F8C0B0BE // Return to Hadron, e1m9
 19D03FFC875589E21EDBB7AB74EF4AEF // Return to Hadron, e1m9, 2016.01.03 update
 {