From f5009478146e10e31a2c577d3c42c39793f308d3 Mon Sep 17 00:00:00 2001
From: Randy Heit <rheit@zdoom.fake>
Date: Thu, 15 Mar 2012 22:59:39 +0000
Subject: [PATCH] - Apply fix from previous commit to Doom-format maps.
 (Previous commit only did it for Hexen.)

SVN r3440 (trunk)
---
 src/p_xlat.cpp | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/p_xlat.cpp b/src/p_xlat.cpp
index 6023b1892..7ece27ae8 100644
--- a/src/p_xlat.cpp
+++ b/src/p_xlat.cpp
@@ -122,7 +122,14 @@ void P_TranslateLineDef (line_t *ld, maplinedef_t *mld)
 		ld->flags = flags | ((linetrans->flags & 0x1f) << 9);
 		if (linetrans->flags & 0x20) ld->flags |= ML_FIRSTSIDEONLY;
 		ld->activation = 1 << GET_SPAC(ld->flags);
-		if (ld->activation == SPAC_AnyCross) ld->activation = SPAC_Impact|SPAC_PCross;	// this is really PTouch
+		if (ld->activation == SPAC_AnyCross)
+		{ // this is really PTouch
+			ld->activation = SPAC_Impact|SPAC_PCross;
+		}
+		else if (ld->activation == SPAC_Impact)
+		{ // In non-UMDF maps, Impact implies PCross
+			ld->activation = SPAC_Impact | SPAC_PCross;
+		}
 		ld->flags &= ~ML_SPAC_MASK;
 
 		if (passthrough && ld->activation == SPAC_Use)