When adding a transaction to an existing account and adding a new account while creating that transaction, GnuCash will prompt you twice asking whether you want to create the new account and display two separate dialog boxes to add the same account.

For instance, when paying an existing bill, I debit an expense account (let's call it "Credit Card (#1234)") and credit a bank account. (I add some of the card number to the account name in order to easily distinguish one account from another.) It's a repetitive transaction, and GnuCash will autocomplete the account name, which is does very well BTW. Let's say the bank issues a new card with a new number because a retailer is not able to properly secure their accounting systems. When I make the next payment with the new card, GnuCash autofills the account name "Credit Card (#1234)", but I change it to "Credit Card (#2345)". When I tab to the next field, GnuCash correctly prompts whether I would like to create the new account. The problem is it will prompt TWICE asking whether the new account should be created. If you select YES with the first prompt, you'll get a second identical prompt. If you select YES with the second prompt, you'll then get another dialog box to add the new account AFTER adding the new account with the first dialog box. (You can cancel the second dialog box. The new account will be created with the first dialog box.) If you select NO with the second prompt, you won't get a second dialog box to add the new account, just the first. If you select NO with the first prompt, the second prompt never appears, and you never get the dialog box to add the new account - which is what a user should expect.

Playing around with the register changing existing account names in order to create new accounts reproduces this issue every time.

Sorry if this is a duplicate bug report. I tried searching the bug database using various keywords and couldn't find an existing bug report.