Usage together with md-select crashes at md-select selection

[hoigo]

When I'm using md-chips-select in a page together with md-select and I select an item of the md-select the click handler of md-chips-select crashes at the following line:

((e.target.nodeName !== "SPAN") ||
    (e.target.attributes.getNamedItem("class").value.indexOf("md-chip-content") === -1)) &&

The clicked element seem to be a SPAN which has no attributes. When trying to access e.target.attributes and call the function getNamedItem it crashes.