Let's say you've got 5 tags for an item, starting with "example", like:
example, apple, fruit, red, delicious
Then you've got another item that only needs 3 tags
example, orange, fruit
However, if you type 'example' first both times, autocomplete will try to fill that really long series of tags that doesn't apply. This patch turns off autocomplete so that you don't have any tags try to complete themselves. Works in all major browsers.