ExtJS.Bugs
ext-2.0.2\source\util\MixedCollection.js:83-84
var old = this.map[key]; if ( old ) {
Will fail if false boolean values (or other falsey values) are stored in the collection.
Suggested fix:
var old = this.map[key]; if ( typeof old !== "undefined" ) {
ext-2.0.2\source\util\MixedCollection.js:391
c[c.length] = {key: k[i], value: items[i], index: i};
Two scripted operations instead of one. Why?
Suggested fix:
c.push( {key: k[i], value: items[i], index: i} );