From 1107bebfcfef572f4abf0dd61c3f875790388815 Mon Sep 17 00:00:00 2001
From: Randy Heit <rheit@zdoom.fake>
Date: Sat, 2 Mar 2013 01:54:40 +0000
Subject: [PATCH] - Redo r4164 fix: Don't clear fake planes when clearing
 skybox planes.

SVN r4172 (trunk)
---
 src/r_3dfloors.cpp |  2 --
 src/r_plane.cpp    | 42 ++++++++++++++++++++++++++++++++++--------
 src/r_polymost.cpp |  2 +-
 3 files changed, 35 insertions(+), 11 deletions(-)

diff --git a/src/r_3dfloors.cpp b/src/r_3dfloors.cpp
index 412a6057a..fbdc34edc 100644
--- a/src/r_3dfloors.cpp
+++ b/src/r_3dfloors.cpp
@@ -140,7 +140,6 @@ void R_3D_EnterSkybox()
 	height_top = NULL;
 	height_cur = NULL;
 	height_max = -1;
-	fakeActive = 0;
 
 	CurrentSkybox++;
 }
@@ -158,7 +157,6 @@ void R_3D_LeaveSkybox()
 	height_top = current.height_top;
 	height_cur = current.height_cur;
 	height_max = current.height_max;
-	fakeActive = height_top != NULL;
 
 	CurrentSkybox--;
 }
diff --git a/src/r_plane.cpp b/src/r_plane.cpp
index d3c5f8c94..16e9b12e2 100644
--- a/src/r_plane.cpp
+++ b/src/r_plane.cpp
@@ -492,13 +492,39 @@ void R_ClearPlanes (bool fullclear)
 {
 	int i, max;
 
-	// kg3D - we can't just clear planes if there are fake planes
-	if(!fullclear && fakeActive) return;
-
-	max = fullclear ? MAXVISPLANES : MAXVISPLANES-1;
-	for (i = 0; i <= max; i++)	// new code -- killough
-		for (*freehead = visplanes[i], visplanes[i] = NULL; *freehead; )
-			freehead = &(*freehead)->next;
+	// Don't clear fake planes if not doing a full clear.
+	if (!fullclear)
+	{
+		for (i = 0; i <= MAXVISPLANES-1; i++)	// new code -- killough
+		{
+			for (visplane_t **probe = &visplanes[i]; *probe != NULL; )
+			{
+				if ((*probe)->sky < 0)
+				{ // fake: move past it
+					probe = &(*probe)->next;
+				}
+				else
+				{ // not fake: move to freelist
+					visplane_t *vis = *probe;
+					*freehead = vis;
+					*probe = vis->next;
+					vis->next = NULL;
+					freehead = &vis->next;
+				}
+			}
+		}
+	}
+	else
+	{
+		max = fullclear ? MAXVISPLANES : MAXVISPLANES-1;
+		for (i = 0; i <= MAXVISPLANES; i++)	// new code -- killough
+		{
+			for (*freehead = visplanes[i], visplanes[i] = NULL; *freehead; )
+			{
+				freehead = &(*freehead)->next;
+			}
+		}
+	}
 
 	if (fullclear)
 	{
@@ -597,7 +623,7 @@ visplane_t *R_FindPlane (const secplane_t &height, FTextureID picnum, int lightl
 		skybox = NULL;
 		alpha = FRACUNIT;
 	}
-		
+
 	// New visplane algorithm uses hash table -- killough
 	hash = isskybox ? MAXVISPLANES : visplane_hash (picnum.GetIndex(), lightlevel, height);
 
diff --git a/src/r_polymost.cpp b/src/r_polymost.cpp
index 92cec1a6e..e7963faa2 100644
--- a/src/r_polymost.cpp
+++ b/src/r_polymost.cpp
@@ -1430,7 +1430,7 @@ void RP_Subsector (subsector_t *sub)
 					frontsector->ceiling_yscale,
 					frontsector->ceiling_angle + frontsector->base_ceiling_angle,
 					frontsector->sky,
-					frontsector->CeilingSkyBox
+					frontsector->CeilingSkyBox,
 					) : NULL;*/
 
 	basecolormap = frontsector->ColorMap;