Submitted by hansfriese, also found by AkshaySrivastav
OpenEdition.buy() might revert due to uint overflow when it should work.
OpenEdition.buy() validates the total funds like below.
Here, amount was declared as uint24 and sale.price is uint72.
And it will revert when amount * sale.price >= type(uint72).max and such cases would be likely to happen e.g. amount = 64(so 2^6), sale.price = 73 * 10^18(so 2^66).
As a result, buy() might revert when it should work properly.
We should modify like below.
stevennevins (Escher) confirmed 
