handling missing default values for defines

which were treated as None in copy_frame #430

Author: ebroecker

src/canmatrix/copy.py

@@ -177,7 +177,7 @@ def copy_frame(frame_id, source_db, target_db):
                 target_db.add_define_default(
                     copy.deepcopy(attribute), copy.deepcopy(source_db.frame_defines[attribute].defaultValue))
             # only default value exists in source but is different to default value in target
-            if attribute not in frame.attributes and \
+            if attribute not in frame.attributes and frame.attribute(attribute, source_db) is not None and \
                     frame.attribute(attribute, source_db) != frame.attribute(attribute, target_db):
                 target_db.frame_by_id(frame.arbitration_id).add_attribute(attribute, frame.attribute(attribute, source_db))
             # update enum data types if needed:
@@ -202,7 +202,7 @@ def copy_frame(frame_id, source_db, target_db):
                         target_db.signal_defines[attribute].values.append(copy.deepcopy(temp_attr))
                         target_db.signal_defines[attribute].update()
                 # only default value exists in source but is different to default value in target
-                if attribute not in sig.attributes and \
+                if attribute not in sig.attributes and sig.attribute(attribute, source_db) is not None and \
                     sig.attribute(attribute, source_db) != sig.attribute(attribute, target_db):
                     target_db.frame_by_id(frame.arbitration_id).signal_by_name(sig.name).add_attribute(attribute, sig.attribute(attribute, source_db))
 

src/canmatrix/tests/test_copy.py

@@ -87,12 +87,16 @@ def test_copy_frame_default_attributes():
     source.add_define_default("some_attribute", "source_frame_default")
     source.add_signal_defines("some_signal_attribute", "STRING")
     source.add_define_default("some_signal_attribute", "source_sig_default")
+    source.add_frame_defines("some_attribute_without_default", "STRING")
 
     #test if default value only defined in source and copied to target
     target = canmatrix.canmatrix.CanMatrix()
+    target.add_frame_defines("some_attribute_without_default", "STRING")
+    target.add_define_default("some_attribute_without_default", "0")
     canmatrix.copy.copy_frame(frame1.arbitration_id, source, target)
     assert target.frames[0].attribute("some_attribute", target) == "source_frame_default"
     assert target.frames[0].signals[0].attribute("some_signal_attribute", target) == "source_sig_default"
+    assert target.frames[0].attribute("some_attribute_without_default", target) == "0"
 
     # test if define already exists, but has another default value:
     target2 = canmatrix.canmatrix.CanMatrix()