Billing address autofill often doesn't work to fill state

http://issues.civicrm.org/jira/browse/CRM-5869 created a checkbox to auto-fill the billing address fields on contribution pages.

It works great, except--sometimes the state field does not copy.

This is a flakey kind of thing. Some times it works, sometimes it doesn't. It seems to work better for some states and malfunctions more often on other states. It seems to depend a little on the timing of when you click various things.

But I can reproduce it on the demo site using both chrome and IE 9 (this is the Drupal demo site and I'm running windows 7). I have also observed it on our Drupal 6 site where it is worse/more pronounced than on the demo site.

To reproduce:

Add a name/address profile to a contribution page along with a billing field using authorize.net as the payment processor. I have one set up here until the demo site resets:

http://drupal.demo.civicrm.org/civicrm/contribute/transact?reset=1&action=preview&id=1

Go to the contribution page and under then "name and address" profile select country "united states" and province "Missouri".

Go to the Billing Name & Address section and click "billing address same as above".

That will probably work correctly. But now follow this sequence:

1. Use the mouse OR keyboard* to select a different state than missouri in the billing section
2. Use the mouse to un-check "billing address same as above"
3. Use the mouse to check "billing address same as above"

About 1 out of 10 times, the auto-fill of the state will malfunction and it will end up on 'select a province' rather than Missouri.

• It seems to make a difference whether you use mouse or keyboard to select the state and the 'same as above' checkbox. After many times of it working correctly with mouse, often it will malfunction if I do it via keyboard. Or vice-versa. Altogether it is very unpredictable and often works correctly for many times in a row before malfunctioning.

On our Drupal 6/CCRM 4.2 site updating the state always fails when you click "same as above"--you can verify here:

https://mobikefed.org/civicrm/contribute/transact?reset=1&id=22&action=preview