Fix UV layer bug in object_utils.object_data_add()

Adding a torus in edit-mode, with 'Generate UVs'
for example would either create another UV layer with the default name or
switch to the default UV layer name if it exists.

Now use the existing UV layer if present.

release/scripts/modules/bpy_extras/object_utils.py

@@ -189,6 +189,14 @@ def object_data_add(context, obdata, operator=None, use_active_layer=True, name=
         scene.update()  # apply location
         # scene.objects.active = obj_new
 
+        # Match up UV layers, this is needed so adding an object with UV's
+        # doesn't create new layers when there happens to be a naming mis-match.
+        uv_new = obdata.uv_layers.active
+        if uv_new is not None:
+            uv_act = obj_act.data.uv_layers.active
+            if uv_act is not None:
+                uv_new.name = uv_act.name
+
         bpy.ops.object.join()  # join into the active.
         if obdata:
             bpy.data.meshes.remove(obdata)