Merge pull request #46 from AugurProject/stop-accumulating-fees-after-fork

stop accumulating fees on parent after fork

Author: KillariDev

solidity/contracts/peripherals/SecurityPool.sol

@@ -101,18 +101,20 @@ contract SecurityPool is ISecurityPool {
 
 	function updateCollateralAmount() public {
 		if (securityBondAllowance == 0) return;
+		uint256 forkTime;
+		(,,forkTime) = zoltar.universes(universeId);
 		(uint64 endTime,,,) = zoltar.questions(questionId);
-		uint256 clampedCurrentTimestamp = block.timestamp > endTime ? endTime : block.timestamp;
-		uint256 clampedLastUpdatedFeeAccumulator = lastUpdatedFeeAccumulator > endTime ? endTime : lastUpdatedFeeAccumulator;
-		uint256 timeDelta = clampedCurrentTimestamp - clampedLastUpdatedFeeAccumulator;
+		uint256 feeEndDate = forkTime == 0 ? endTime : forkTime;
+		uint256 clampedCurrentTimestamp = block.timestamp > feeEndDate ? feeEndDate : block.timestamp;
+		uint256 timeDelta = clampedCurrentTimestamp - lastUpdatedFeeAccumulator;
 		if (timeDelta == 0) return;
 
 		uint256 newCompleteSetCollateralAmount = completeSetCollateralAmount * SecurityPoolUtils.rpow(currentRetentionRate, timeDelta, SecurityPoolUtils.PRICE_PRECISION) / SecurityPoolUtils.PRICE_PRECISION;
 		uint256 delta = completeSetCollateralAmount - newCompleteSetCollateralAmount;
 		totalFeesOvedToVaults += delta;
 		feeIndex += delta * SecurityPoolUtils.PRICE_PRECISION / securityBondAllowance;
 		completeSetCollateralAmount = newCompleteSetCollateralAmount;
-		lastUpdatedFeeAccumulator = block.timestamp;
+		lastUpdatedFeeAccumulator = feeEndDate < block.timestamp ? feeEndDate : block.timestamp;
 
 		emit UpdateCollateralAmount(totalFeesOvedToVaults, completeSetCollateralAmount);
 	}

solidity/ts/tests/testPeripherals.ts

@@ -104,7 +104,7 @@ describe('Peripherals Contract Test Suite', () => {
 		assert.strictEqual(liquidatorVault.repDepositShare / PRICE_PRECISION, repDeposit+(repDeposit * 10n), 'liquidator should have all the rep in the pool')
 	})
 
-	test('Open Interest Fees', async () => {
+	test('Open Interest Fees (non forking)', async () => {
 		const questionData = await getQuestionData(client, questionId)
 		assert.strictEqual(questionData.endTime > dateToBigintSeconds(new Date), true, 'market has already ended')
 		const securityPoolAllowance = repDeposit / 4n
@@ -169,12 +169,13 @@ describe('Peripherals Contract Test Suite', () => {
 		assert.strictEqual(newCompleteSetBalances[1], 0n, 'Did not lose complete sets')
 		assert.strictEqual(newCompleteSetBalances[2], 0n, 'Did not lose complete sets')
 		assert.strictEqual(await getCurrentRetentionRate(client, securityPoolAddresses.securityPool), MAX_RETENTION_RATE, 'retention rate was not at max after zero complete sets');
-
 		// forking
 		await createCompleteSet(client, securityPoolAddresses.securityPool, openInterestAmount)
 		const repBalance = await getERC20Balance(client, getRepTokenAddress(genesisUniverse), securityPoolAddresses.securityPool)
+
 		await triggerFork(client, mockWindow, questionId)
 		await forkSecurityPool(client, securityPoolAddresses.securityPool)
+		const totalFeesOvedToVaultsRightAfterFork = await getTotalFeesOvedToVaults(client, securityPoolAddresses.securityPool)
 		assert.strictEqual(await getSystemState(client, securityPoolAddresses.securityPool), SystemState.PoolForked, 'Parent is forked')
 		assert.strictEqual(0n, await getERC20Balance(client, getRepTokenAddress(genesisUniverse), securityPoolAddresses.securityPool), 'Parents original rep is gone')
 		await migrateVault(client, securityPoolAddresses.securityPool, QuestionOutcome.Yes)
@@ -189,6 +190,9 @@ describe('Peripherals Contract Test Suite', () => {
 		await startTruthAuction(client, yesSecurityPool.securityPool)
 		assert.strictEqual(await getSystemState(client, yesSecurityPool.securityPool), SystemState.Operational, 'yes System should be operational right away')
 		assert.strictEqual(await getCompleteSetCollateralAmount(client, yesSecurityPool.securityPool), openInterestAmount, 'child contract did not record the amount correctly')
+
+		const totalFeesOvedToVaultsAfterFork = await getTotalFeesOvedToVaults(client, securityPoolAddresses.securityPool)
+		assert.strictEqual(totalFeesOvedToVaultsRightAfterFork, totalFeesOvedToVaultsAfterFork, 'parents fees should be frozen')
 	})
 
 	test('two security pools with disagreement', async () => {
@@ -367,4 +371,6 @@ describe('Peripherals Contract Test Suite', () => {
 		assert.strictEqual(await getSystemState(client, yesSecurityPool.securityPool), SystemState.Operational, 'yes System should be operational right away')
 		assert.strictEqual(await getCompleteSetCollateralAmount(client, yesSecurityPool.securityPool), 0n, 'child contract did not record the amount correctly')
 	})
+
+	// - todo test that users can claim their stuff (shares+rep) even if zoltar forks after market ends
 })