Pasting a value with a comma results in unexpected results

When pasting a value with a comma, then selecting the matched item, the original search is retained and appended with the auto complete value. As a result, the expected item is not found.

For example, let's say I'm search for an company whose name is Foo, LLC. If I start typing Foo and select Foo, LLC, it works fine, but if I paste in Foo, LLC and then select the matching Foo, LLC, then what is actually populated in the search is Foo, LLC Foo, LLC

At first glance, I'd imagine it is related to the code in Drupal.autocomplete.options.select

Perhaps there needs to be two code paths?

1) For a tags style input
2) A single select