Log statement causing trouble

[orslumen]

The method insertBefore in dom.js starts with the following debug statement:

log.debug('insert %s Before %s', newChild.nodeName, refChild.nodeName);

But results in a TypeError: Cannot read property 'nodeName' of null when the refChild (or newChild is undefined). This can be fixed as follows:

log.debug('insert %s Before %s', newChild && newChild.nodeName, refChild && refChild.nodeName);

See commit orslumen@c22faaf

But would it not be better (performance wise) to comment out all log statements, or to add something like if (Log.level <= debug) { log.debug(...) } to all debug statements?