From ef9f3da31de97fa8c3645f6c8465847412c2ad94 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@zdoom.fake>
Date: Fri, 4 Mar 2016 14:41:24 +0100
Subject: [PATCH] - do not use the precalculated coordinates for non-linked
 portals because they are not static.

---
 src/gl/scene/gl_portal.h | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/src/gl/scene/gl_portal.h b/src/gl/scene/gl_portal.h
index 6b94e649c..89431b1c2 100644
--- a/src/gl/scene/gl_portal.h
+++ b/src/gl/scene/gl_portal.h
@@ -192,10 +192,23 @@ struct GLLinePortal : public GLPortal
 
 	GLLinePortal(FGLLinePortal *line)
 	{
-		v1 = line->v1;
-		v2 = line->v2;
-		dx = line->dx;
-		dy = line->dy;
+		if (line->reference->mType != PORTT_LINKED)
+		{
+			// For non-linked portals we must check the actual linedef.
+			line_t *lline = line->reference->mDestination;
+			v1 = lline->v1;
+			v2 = lline->v2;
+			dx = lline->dx;
+			dy = lline->dy;
+		}
+		else
+		{
+			// For linked portals we can check the merged span.
+			v1 = line->v1;
+			v2 = line->v2;
+			dx = line->dx;
+			dy = line->dy;
+		}
 	}
 
 	line_t *line()