- fixed: 3D floor that extend into the real sector's floor were not clipped properly.

The only check being done on this was done after processing for the renderer which simply is too late.

src/gl/scene/gl_walls.cpp

@@ -1392,6 +1392,12 @@ void GLWall::DoFFloorBlocks(seg_t * seg, sector_t * frontsector, sector_t * back
 			ff_topleft = topleft;
 			ff_topright = topright;
 		}
+		if (ff_bottomleft < bottomleft && ff_bottomright < bottomright)
+		{
+			// the new section extends into the floor.
+			ff_bottomleft = bottomleft;
+			ff_bottomright = bottomright;
+		}
 
 		// do all inverse floors above the current one it there is a gap between the
 		// last 3D floor and this one.