L3 - Minimum base provided can be circumvent about niftyswap HOT 5 CLOSED

Looking back at it, I think this is more of a sanity check to make sure decimals are accounted for. Someone could accidentally set up a really bad price when opening a new market for instance. I don't think the rounding error rational in the in-line comment is sound, the rounding error will not be more significant based on a small initial liquidity being added.

This requirement does prevent currencies that have smaller number of decimals and might be worth considering removing.

What do you think?

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I think this is more of a sanity check to make sure decimals are accounted for. Someone could accidentally set up a really bad price when opening a new market for instance

I am not sure if I follow you there, when you first enter liquidity the UX should be taking care of the decimals, for example in Uniswap, adding 1 ETH of liquidity adds 10**18 WEI, the user can't add 1 WEI by mistake.

I think that the require is intended to protect the second liquidity provider, if a pool has 1 wei / 1 wei of liquidity the next provider is forced to maintain the 1:1 ratio, usually this is not a problem, because the pool should get arbitraged until the real ratio is reached, but when the liquidity is that low nobody can do any trade, so that doesn’t happens.

I market it as a low severity issue because it's only an inconvenience, it exists a simple fix if a "troll" starts to create pools with 1/1 liquidity. A contract could add liquidity to such pools and trade at the same time, enabling trades again.

Because it exists a simple fix, I would be comfortable tagging this as won’t-fix, but It would be a good idea to monitor pools in case one of these "trolls" appears.

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Yeah, the trolling would be a bit annoying, but indeed one can add liquidity & trade to correct ratio in a single tx to correct the ratio. Good to keep track of indeed.

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@Agusx1211 I was thinking about this, and what if someone adds a 10000 wei : 1 X as first liquidity, where X is a fungible tokens with many decimals (hence 1 is the lowest value possible). Now the "trolling" is truly effective since the ratio 10000/1 would need to be maintained for all future added liquidity. Are we certain that we can correct that ratio?

We would need to do a contract call like :

  niftyswapContract.addLiquidity(...);
  niftyswapContract.baseToToken(...);
  ...

So if ratio is 10000 A / 1 B we need to

• Add 999000 A and 999 B giving you 10000000 A / 1000 B
• Sell 99,000 B to get a 100,000 A / 100,000 B ratio
• Remove liquidity

Now my main worry is under which scenario might it be impossible to get enough B liquidity.

What do you think @Agusx1211 ?

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Fixing the ratio can also be done by performing a trade; I cannot think of any situation that cannot be fixed in a safe manner by using a contract.

Worst case scenario, the pool is left broken, and the exchange has to be re-deployed. Maybe the UI could raise a warning if a user tries to add liquidity to a pool with less than 100000000 base liquidity?

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