Saxon

The problem is that TinyAttributeImpl does not implement the method getSystemId(), so it is defaulting to the implementation in TinyNodeImpl.getSystemId(), which is incorrect for attribute nodes because it uses an attribute node number to index into the table of system IDs, when this table is indexed by element node numbers.

Therefore the system ID returned for attribute nodes (in a tinyTree) is incorrect.

Fix by adding to TinyAttributeImpl:

@Override
    public String getSystemId() {
        NodeInfo parent = getParent();
        return parent == null ? null : getParent().getSystemId();
    }

Workaround: use ../saxon:system-id().