nodesForXPath:error: logs error, but error is nil

[ronhippler]

The console logs XPath error : Undefined namespace prefix and XPath error : Invalid expression, which is correct, but the error points to nil.

With a breakpoint at

    if (xpathObj == NULL) {
        if (error) *error = [[self class] lastError];
        result = nil;
    }

i see that lastError = nil