同样的例子在4.2.1 SDK中，确实按照分组列不再工作。听起来像回归给我，你应该通知Sencha。

The same example is present in 4.2.1 SDK, and indeed sorting by the grouped column doesn't work anymore. Sounds like a regression to me, you should notify Sencha.

编辑：

这是方法的代码sort $ sort $ sort $ / code>已更改。恢复以前的版本修复了行为（请参阅我的评论以找到修改的行）：

That's the code of the method Ext.data.Store#sort that has changed. Restoring the previous version fixes the behaviors (see my comments to find the modified lines):

Ext.define(null, {
    override: 'Ext.data.Store'

    ,sort: function(sorters, direction, where, doSort) {
        var me = this,
            sorter,
            newSorters;

        if (Ext.isArray(sorters)) {
            doSort = where;
            where = direction;
            newSorters = sorters;
        }
        else if (Ext.isObject(sorters)) {
            doSort = where;
            where = direction;
            newSorters = [sorters];
        }
        else if (Ext.isString(sorters)) {
            sorter = me.sorters.get(sorters);

            if (!sorter) {
                sorter = {
                    property : sorters,
                    direction: direction
                };
                newSorters = [sorter];
            }
            else if (direction === undefined) {
                sorter.toggle();
            }
            else {
                sorter.setDirection(direction);
            }
        }

        if (newSorters && newSorters.length) {
            newSorters = me.decodeSorters(newSorters);
            if (Ext.isString(where)) {
                if (where === 'prepend') {
                    // <code from 4.2.1>
                    // me.sorters.insert(0, newSorters);
                    // </code from 4.2.1>

                    // <code from 4.2.0>
                    sorters = me.sorters.clone().items;

                    me.sorters.clear();
                    me.sorters.addAll(newSorters);
                    me.sorters.addAll(sorters);
                    // </code from 4.2.0>
                }
                else {
                    me.sorters.addAll(newSorters);
                }
            }
            else {
                me.sorters.clear();
                me.sorters.addAll(newSorters);
            }
        }

        if (doSort !== false) {
            me.fireEvent('beforesort', me, newSorters);
            me.onBeforeSort(newSorters);

            sorters = me.sorters.items;
            if (sorters.length) {

                me.doSort(me.generateComparator());
            }
        }
    }
});