Hi @mnovak,
In the issue link: A question about the "when" merge usage - #3 by darcyl, the db has contained the node’s configuration data and when another XML modifies the data, then the node with the when is deleted
In this example, the node’s configuration data isn’t stored in the db, so I think the error-message in when should be reported, not sure whether the understanding is right?
RFC 7950 - The YANG 1.1 Data Modeling Language, In the RFC, it also said if a configuration data is modified which leads to the when expression false.
If a request modifies a configuration data node such that any
node’s “when” expression becomes false, then the node in the data
tree with the “when” expression is deleted by the server.