Merge pull request #1398 from KLayout/issue-1397

Issue-1397: possible solution

src/pya/pya/pyaMarshal.cc

@@ -690,6 +690,11 @@ PyObject *object_from_variant (tl::Variant &var, PYAObjectBase *self, const gsi:
 
       }
 
+    } else {
+
+      //  This is the case for return values that prefer to be copied (e.g. from const &)
+      prefer_copy = atype.prefer_copy ();
+
     }
 
     return object_to_python (obj, self, cls, pass_obj, is_const, prefer_copy, can_destroy);

src/rba/rba/rbaMarshal.cc

@@ -711,6 +711,11 @@ static VALUE object_from_variant (tl::Variant &var, Proxy *self, const gsi::ArgT
 
       }
 
+    } else {
+
+      //  This is the case for return values that prefer to be copied (e.g. from const &)
+      prefer_copy = atype.prefer_copy ();
+
     }
 
     return object_to_ruby (obj, self, cls, pass_obj, is_const, prefer_copy, can_destroy);

testdata/python/dbLayoutTest.py

@@ -1156,6 +1156,35 @@ class DBLayoutTest(unittest.TestCase):
     self.assertEqual(shape.property(42), None)
     self.assertEqual(shape.property(42.0), None)
 
+  # Bug #1397
+  def test_bug1397(self):
+
+    testtmp = os.getenv("TESTTMP_WITH_NAME", os.getenv("TESTTMP", "."))
+    tmp = os.path.join(testtmp, "tmp.gds")
+
+    l = pya.Layout()
+
+    c = l.create_cell("test_cell")
+
+    li = pya.LayerInfo(1, 0)
+    t = pya.Trans.R180
+    c.add_meta_info(pya.LayoutMetaInfo("kfactory:li", li, None, True))
+    c.add_meta_info(pya.LayoutMetaInfo("kfactory:t", t, None, True))
+
+    l.write(tmp)
+
+    l2 = pya.Layout()
+    l2.read(tmp)
+
+    c2 = l2.cell("test_cell")
+
+    li = c2.meta_info("kfactory:li").value
+    self.assertEqual(li.layer, 1)
+    self.assertEqual(li.datatype, 0)
+
+    t = c2.meta_info("kfactory:t").value
+    self.assertEqual(str(t), "r180 0,0")
+    
 
 # run unit tests
 if __name__ == '__main__':