add item in the Ext.util.MixedCollection

[szub]

I add new item:

add('itemkey', 12);

Then

add('itemkey', 0)

I want to change item with key 'itemkey', but it is not happen.
Then I found the bug in you code (Ext JS 4.2):

    insert : function(index, key, obj) {
        if (Ext.isIterable(key)) {
            return this.doInsert(index, key, obj);
        }
        return (obj ? this.doInsert(index, [key], [obj]) : this.doInsert(index, [key]))[0];
    },

obj=0 treated as false...

[evant]

Thanks for the post, we already have a ticket open for this: EXTJSIV-9269