[xml] missing check in tree.c?

[<oliverst online de>]

in tree.c line 3850 (libxml2-2.6.11) you find this code:

    /* if parent != NULL we already registered the node above */
    if (parent == NULL && xmlRegisterNodeDefaultValue)
        xmlRegisterNodeDefaultValue((xmlNodePtr)ret); 

I recognised, that where the xmlRegisterNodeDefaultValue is also used
and the code always looks like this:

if ((__xmlRegisterCallbacks) && (xmlRegisterNodeDefaultValue))

Is there is this additional check for __xmlRegisterCallbacks missing?