Liquidation of CDPs with pending StabilityPool gains about dev HOT 3 CLOSED

Alternative solution 2: restrict withdrawGainsFromSPtoCDP to large positions with >$1000 worth of ETH as collateral. Also restrict liquidateCDPs to sequences of CDPs that do not have stability deposits, i.e. revert if any CDP along the way is linked to an SP. CDPs with stability deposits can thus only be liquidated individually via liquidate().

Rationale:

• We'd also probably expect borrowers close to the MCR to be less likely to be stability pool users (except in black swan events). So liquidateCDPs should still be useful.
• The main motivation behind withdrawGainsFromSPtoCDP is to make stability deposits more attractive and to eventually increase the amount of deposits. Given the expected wealth distribution in crypto, the stability pool will likely be dominated by whales anyway, so barring out small CDPs might not change the overall deposited amount too much.

from dev.

Liquidations no longer require a hint - I'll mark this issue closed.

Instead of calling withdrawFromSPtoCDP and applying the Borrower's ETH gain earned by his stability deposit, liquidations now use a new function, getNewICRFromPendingSPGain, to check what the ICR would be if the Borrower's pending ETH gain was applied.

If the CDP would be left active, the liquidation halts - otherwise, it proceeds.

With this approach no reinsertion is required (and nor a hint). It also gives a significant gas saving.

from dev.

Liquidations are now completely decoupled from SP gains. Liquidation of a trove is conditional only on the raw ICR of the trove.

Borrowers can still voluntarily call withdrawFromSPtoCDP, and withdraw their ETH gain to their trove.

from dev.