Bug: Material belongs to old camp after copying

[LFanonym]

When copying from an old Camp all the Material loses the binding to the materialLists. If you try to manually set it again a error apears:

materialList: must belong to the same camp.

Only workaround I know is to manually recreate the old materialList

[BacLuc]

Ui ui ui. Thank you for the bug report.
I can confirm this behavior.

[pmattmann]

The simplest solution would be the following:

If an activity is copied across camps, the materials are not copied.

Reason:
There is no guarantee that the material lists from the source-camp also exist in the target-camp.

Alternative:
We allow the material list to be 'empty' after copying - so the entries can then be added to a list.
However, I would still prohibit deleting the material list on an material-entry.