hull-of-hull bug: bugxi and test for exposing it

src/GeometryEvaluator.cc

@@ -54,16 +54,16 @@ shared_ptr<const Geometry> GeometryEvaluator::evaluateGeometry(const AbstractNod
 		// If not found in any caches, we need to evaluate the geometry
 		if (N) {
 			this->root = N;
-		}
-		else {
+		}	
+    else {
 			Traverser trav(*this, node, Traverser::PRE_AND_POSTFIX);
 			trav.execute();
+		}
 
-			if (!allownef) {
-				if (shared_ptr<const CGAL_Nef_polyhedron> N = dynamic_pointer_cast<const CGAL_Nef_polyhedron>(this->root)) {
-					this->root.reset(N->convertToPolyset());
-					smartCache(node, this->root);
-				}
+		if (!allownef) {
+			if (shared_ptr<const CGAL_Nef_polyhedron> N = dynamic_pointer_cast<const CGAL_Nef_polyhedron>(this->root)) {
+				this->root.reset(N->convertToPolyset());
+				smartCache(node, this->root);
 			}
 		}
 		return this->root;

testdata/scad/features/hull3-tests.scad

@@ -3,12 +3,18 @@ hull();
 // No children
 hull() { }
 
-hull() {
-  cylinder(r=10, h=1);
-  translate([0,0,10]) cube([5,5,5], center=true);
-}
+// Hull of hull (forces internal cache to be initialized; this has caused a crash earlier)
+translate([25,0,0]) hull() hull3test();
 
-translate([25,0,0]) hull() {
+module hull3test() {
+  hull() {
+    cylinder(r=10, h=1);
+    translate([0,0,10]) cube([5,5,5], center=true);
+  }
+}
+hull3test();
+
+translate([50,0,0]) hull() {
   translate([0,0,10]) cylinder(r=3);
   difference() {
     cylinder(r=10, h=4, center=true);

tests/regression/dumptest/hull3-tests-expected.csg

@@ -1,13 +1,27 @@
 group() {
 	hull();
 	hull();
-	hull() {
-		cylinder($fn = 0, $fa = 12, $fs = 2, h = 1, r1 = 10, r2 = 10, center = false);
-		multmatrix([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 10], [0, 0, 0, 1]]) {
-			cube(size = [5, 5, 5], center = true);
+	multmatrix([[1, 0, 0, 25], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+		hull() {
+			group() {
+				hull() {
+					cylinder($fn = 0, $fa = 12, $fs = 2, h = 1, r1 = 10, r2 = 10, center = false);
+					multmatrix([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 10], [0, 0, 0, 1]]) {
+						cube(size = [5, 5, 5], center = true);
+					}
+				}
+			}
 		}
 	}
-	multmatrix([[1, 0, 0, 25], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+	group() {
+		hull() {
+			cylinder($fn = 0, $fa = 12, $fs = 2, h = 1, r1 = 10, r2 = 10, center = false);
+			multmatrix([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 10], [0, 0, 0, 1]]) {
+				cube(size = [5, 5, 5], center = true);
+			}
+		}
+	}
+	multmatrix([[1, 0, 0, 50], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
 		hull() {
 			multmatrix([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 10], [0, 0, 0, 1]]) {
 				cylinder($fn = 0, $fa = 12, $fs = 2, h = 1, r1 = 3, r2 = 3, center = false);