"Paste attributes" and "Remove note" not enabled when an attribute is copied or a note is attached to a node

Copying an attribute ( Edit → Node extensions → Copy attributes) was enabling pasting that attribute ( Edit → Node extensions → Paste attributes). Opening another map (I used Help → Documentation) would enable it because it sent the checkOnPopup signal PasteAttributes was listening for. Changing the EnabledAction annotation from checkOnPopup to *checkOnPopup" fixes the issue.

The same issue keeps Edit → Note → Remove note inactive even when a node with a note is selected.