[4.1b2] CellEditing is confused by complex cell content

[lagnat]

In this example, the editor doesn't occupy the entire cell. It seems to be related to the renderer producing other than plain text.

Ext.onReady(function() {
    Ext.create('Ext.data.Store', {
        storeId:'simpsonsStore',
        fields:['name', 'email'],
        data:{'items':[
            { 'name': 'Marge', "email":"marge@simpsons.com" }
        ]},
        proxy: {
            type: 'memory',
            reader: {
                type: 'json',
                root: 'items'
            }
        }
    });

    Ext.create('Ext.grid.Panel', {
        title: 'Simpsons',
        store: Ext.data.StoreManager.lookup('simpsonsStore'),
        plugins: [
            Ext.create('Ext.grid.plugin.CellEditing', {
                clicksToEdit: 1
            })
        ],
        columns: [{
                header: 'Name',
                dataIndex: 'name',
                field: new Ext.form.TextField({
                    allowBlank: false
                })
            }, {
                header: 'Email',
                dataIndex: 'email',
                flex: 1,
                field: new Ext.form.TextField({
                    allowBlank: false
                }),
                renderer: function(value) {
                    return "<span>" + value + "</span>";
                }
            }
        ],
        width: 400,
        renderTo: Ext.getBody()
    });

});