Changing the currency of a vendor when there is an unposted bill from that vendor causes a subsequent posting of the bill to be handled incorrectly.

Reproduction steps:

Create two accounts payable accounts, one in USD and the other in CAD.

Create a new vendor. Let the new vendor currency default to USD.

Create a new bill for the vendor. Fill out the invoice entries with a total of $1,000, using expense accounts that are in CAD.

Click on "Post". Notice the bill is being posted to the accounts payable account that is in USD. Realize you forgot to set the vendor currency to CAD. Click "Cancel".

Edit the vendor and change its currency to CAD.

Go back to the bill and click on "Post bill". Notice it is now being posted to the accounts payable account that is in USD. Click "OK".

Expected behavior:

Bill is posted in CAD into the accounts payable account in CAD, with an amount of CA$1,000.

Actual behavior:

Warning dialog box "One or more of the entries are for accounts different from the invoice/bill currency. You will be asked a conversion rate for each." Click "Close"

Transfer funds dialog box pops up showing a transfer from currency CAD to currency CAD with an exchange rate of 0.00.  All fields except the "Cancel" and "OK" button are greyed out.

If you click on "OK", it enters a transaction into the accounts payable account in CAD with an amount of CA$0.00.