There are ERC20 tokens that charge fee for every transfer() / transferFrom().
Vault.sol#addValue() assumes that the received amount is the same as the transfer amount, and uses it to calculate attributions, balance amounts, etc.
But, the actual transferred amount can be lower for those tokens.
Therefore its recommended to use the balance change before and after the transfer instead of the amount.
This way you also support the tokens with transfer fee - that are popular.
For this contest, 48 reports were submitted by wardens detailing gas optimizations. The report highlighted below by c3phas received the top score from the judge.
The following wardens also submitted reports: sakman,
tnevler,
ajtra,
adriro,
lukris02,
horsefacts,
B2,
peiw,
djxploit,
KoKo,
Dravee,
indijanc,
gogo,
RockingMiles,
Waze,
0xSmartContract,
SooYa,
0xRoxas,
Amithuddar,
imare,
SadBase,
0xNazgul,
neko_nyaa,
halden,
shark,
__141345__,
carlitox477,
Picodes,
karanctf,
emrekocak,
RedOneN,
erictee,
0xbepresent,
cylzxje,
ReyAdmirado,
Ruhum,
Mathieu,
ch0bu,
durianSausage,
oyc_109,
Awesome,
skyle,
Bnke0x0,
0x1f8b,
ballx,
leosathya, and
RaymondFam.
