Balance overflowing in sha3_memSizeNoQuadraticCost31

[adria0]

In the https://github.com/ethereum/tests/blob/v7.0.0/BlockchainTests/ValidBlocks/VMTests/vmSha3Test/sha3_memSizeNoQuadraticCost31.json test

the initial balance is

tests/BlockchainTests/ValidBlocks/VMTests/vmSha3Test/sha3_memSizeNoQuadraticCost31.json

Line 15 in 5e4539b

"balance" : "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff",

and after sending 0x7c, the final balance is

tests/BlockchainTests/ValidBlocks/VMTests/vmSha3Test/sha3_memSizeNoQuadraticCost31.json

Line 106 in 5e4539b

"balance" : "0x7b",

Is this the expected way to manage overflows? I think that will have more sense to do saturating overflow or just reject the tx.

(since is filled by geth, cc/@karalabe)

[karalabe]

Weeell, I think that's undefined behavior which we should not test. A gazillion things can go wrong all over the place if balances start overflowing, something which cannot ever happen in a live network. It would be a pointless can of worms to start speccing what clients should do in these cases.

[adria0]

related #688

[winsvega]

Fixed
#695