Copy does not work in 1.5.4 or 1.6.0a4. It does work in 1.1.6.
There are only two command IDs involved. This is code for Go_Copy.
Go_Copy{
macroinfo=_("Copy URL Bar contents to the Clipboard");
id(ID_SELECT_URL); id(ID_EDIT_COPY);
}
One of those two Command IDs no longer functions like it did in version 1.1.6.