Fix acceptance tests after changes for gas price enabled (#1466)

* Ensure no impact if gas price is not enabled (fixes breaking acceptance tests)
* Restore historic behaviour when gas price not enabled (to fix acc tests)

Author: SatpalSandhu61

consensus/ethash/consensus.go

@@ -625,10 +625,12 @@ var (
 // included uncles. The coinbase of each uncle block is also rewarded.
 func accumulateRewards(config *params.ChainConfig, state *state.StateDB, header *types.Header, uncles []*types.Header) {
 
-	// Quorum: Disable reward for Quorum if gas price is not enabled,
-	// otherwise static block reward will impact Raft (even though the gas price is zero)
+	// Quorum:
+	// Historically, quorum was adding (static) reward to account 0x0.
+	// So need to ensure this is still the case if gas price is not enabled, otherwise reward goes to coinbase.
+	headerCoinbase := header.Coinbase
 	if config.IsQuorum && !config.IsGasPriceEnabled(header.Number) {
-		return
+		headerCoinbase = common.Address{0x0000000000000000000000}
 	}
 
 	// Select the correct block reward based on chain progression
@@ -653,7 +655,7 @@ func accumulateRewards(config *params.ChainConfig, state *state.StateDB, header
 		r.Div(blockReward, big32)
 		reward.Add(reward, r)
 	}
-	state.AddBalance(header.Coinbase, reward)
+	state.AddBalance(headerCoinbase, reward)
 }
 
 // Quorum: wrapper for accumulateRewards to be called by raft minter

core/tx_pool.go

@@ -1287,7 +1287,7 @@ func (pool *TxPool) promoteExecutables(accounts []common.Address) []*types.Trans
 		}
 		log.Trace("Removed old queued transactions", "count", len(forwards))
 		var drops types.Transactions
-		if !pool.chainconfig.IsQuorum || pool.chainconfig.IsGasPriceEnabled(pool.chain.CurrentBlock().Header().Number) {
+		if !isQuorum || pool.chainconfig.IsGasPriceEnabled(pool.chain.CurrentBlock().Header().Number) {
 			// Drop all transactions that are too costly (low balance or out of gas)
 			drops, _ = list.Filter(pool.currentState.GetBalance(addr), pool.currentMaxGas)
 			for _, tx := range drops {

raft/minter.go

@@ -259,13 +259,23 @@ func (minter *minter) createWork() *work {
 	parentNumber := parent.Number()
 	tstamp := generateNanoTimestamp(parent)
 
+	// Quorum:
+	// If gas price is enabled on next block then set correct etherbase for reward
+	// Note that historically, quorum was setting coinbase to 0x0,
+	// so need to ensure this is still the case if gas price is not enabled.
+	coinbase := common.Address{0x0000000000000000000000}
+	newBlockNumber := parentNumber.Add(parentNumber, common.Big1)
+	if minter.config.IsGasPriceEnabled(newBlockNumber) {
+		coinbase = minter.coinbase
+	}
+
 	header := &types.Header{
 		ParentHash: parent.Hash(),
-		Number:     parentNumber.Add(parentNumber, common.Big1),
+		Number:     newBlockNumber,
 		Difficulty: ethash.CalcDifficulty(minter.config, uint64(tstamp), parent.Header()),
 		GasLimit:   minter.eth.calcGasLimitFunc(parent),
 		GasUsed:    0,
-		Coinbase:   minter.coinbase,
+		Coinbase:   coinbase,
 		Time:       uint64(tstamp),
 	}