the _propCache and _attrCache were twisted.

[LeoYuan]

bug description

the internal variables _propCache and _attrCache are twisted, so some code went wrong.

how to reproduce?

af('body').prop('tagName');
af('body').data('key', {a: 3});
af('body').prop('tagName');

how to fix?

to add one more judgement to make code much more robust.

var val = (this[0].afmCacheId && _attrCache[this[0].afmCacheId][attr]) ? (this[0].afmCacheId && _attrCache[this[0].afmCacheId][attr]) : this[0].getAttribute(attr);

changed to

var val = (this[0].afmCacheId && _attrCache[this[0].afmCacheId] && _attrCache[this[0].afmCacheId][attr]) ? _attrCache[this[0].afmCacheId][attr] : this[0].getAttribute(attr);