[GNC] How to balance correctly a particular transaction which involves debt?

[Daniel Fishman]

Hello,

Suppose that you go with your friend to a shop, and then a friend
remembers that he forgotten his credit card and asks you to pay
for his merchandise. He intends to return the money later. You pay
in the shop (for example, buy a book) using your credit card. Then
a few days later the friend returns his debt - for example, by paying
you cash.

I want to document those facts in gnucash.

Since the payment to the shop was made by the credit card, an account
'Expenses:<shop name>' is debited, while an account 'Liability:<credit card name>'
is credited. I also want to make it explicit that a friend incurred
debt due to this transaction. Therefore, it seems to me that this transaction
should also contain a split which debits an account
'Assets:Accounts receivable:<friend's name>'. But which account should be
credited to balance the transaction? Suppose that I credit some
artificial account, like 'Equity:Balancing account' and succeed to
balance the transaction. Then when the friend pays his debt, an account
'Assets:Accounts receivable:<friend's name>' should be credited, and
an account 'Assets:Cash' should be debited, but what about an account
'Equity:Balancing account' - should it just be left as is (that is,
not debited)? It seems a bit artificial.

What is the accepted way to document such transactions?