From e3317ecc64659ae8be2a7b02d4df17dad6d875db Mon Sep 17 00:00:00 2001
From: "David Eccles (gringer)" <github@gringer.org>
Date: Fri, 6 Dec 2013 13:14:09 +1300
Subject: Fail if any polygon points for rotate_extrude are less than 0


diff --git a/src/PolySetCGALEvaluator.cc b/src/PolySetCGALEvaluator.cc
index bc9206f..e5eba2b 100644
--- a/src/PolySetCGALEvaluator.cc
+++ b/src/PolySetCGALEvaluator.cc
@@ -457,7 +457,13 @@ PolySet *PolySetCGALEvaluator::rotateDxfData(const RotateExtrudeNode &node, DxfD
 	{
 		double max_x = 0;
 		for (size_t j = 0; j < dxf.paths[i].indices.size(); j++) {
-			max_x = fmax(max_x, dxf.points[dxf.paths[i].indices[j]][0]);
+			double point_x = dxf.points[dxf.paths[i].indices[j]][0];
+			if(point_x < 0){
+				PRINT("ERROR: all points for rotate_extrude() must have non-negative X coordinates");
+				PRINT((boost::format("[Point %d on path %d has X coordinate %f]") % j % i % point_x).str());
+				return NULL;
+			}
+			max_x = fmax(max_x, point_x);
 		}
 
 		int fragments = get_fragments_from_r(max_x, node.fn, node.fs, node.fa);
-- 
cgit v0.10.1