Fix crash on invalid faces (#1541)

* Fix crash on invalid faces

* Add test

---------

Co-authored-by: AU <[email protected]>

Author: openvmp

cadquery/occ_impl/shapes.py

@@ -1365,6 +1365,8 @@ def tessellate(
 
             loc = TopLoc_Location()
             poly = BRep_Tool.Triangulation_s(f.wrapped, loc)
+            if poly is None:
+                continue
             Trsf = loc.Transformation()
             reverse = (
                 True

tests/test_cadquery.py

@@ -5732,3 +5732,16 @@ def test_iterators(self):
 
         res7 = list(fs.siblings(c, "Edge", 2))
         assert len(res7) == 2
+
+    def test_tessellate(self):
+
+        # happy flow
+        verts, tris = Face.makePlane(1, 1).tessellate(1e-3)
+
+        assert len(verts) == 4
+        assert len(tris) == 2
+
+        # this should not crash, but return no verts
+        verts, _ = Face.makePlane(1e-9, 1e-9).tessellate(1e-3)
+
+        assert len(verts) == 0