Add rejection reason to go-ethereum EstimateGas

reject-reason.patch

--- core/vm/interpreter.go	(revision 744428cb03ea8de8f219708f57d2e197acb6689b)
+++ core/vm/interpreter.go	(date 1524449729000)
@@ -102,7 +102,7 @@
 //
 // It's important to note that any errors returned by the interpreter should be
 // considered a revert-and-consume-all-gas operation except for
-// errExecutionReverted which means revert-and-keep-gas-left.
+// ErrExecutionReverted which means revert-and-keep-gas-left.
 func (in *Interpreter) Run(contract *Contract, input []byte) (ret []byte, err error) {
 	// Increment the call depth which is restricted to 1024
 	in.evm.depth++
@@ -215,7 +215,7 @@
 		case err != nil:
 			return nil, err
 		case operation.reverts:
-			return res, errExecutionReverted
+			return res, ErrExecutionReverted
 		case operation.halts:
 			return res, nil
 		case !operation.jumps:
--- core/vm/evm.go	(revision 744428cb03ea8de8f219708f57d2e197acb6689b)
+++ core/vm/evm.go	(date 1524449729000)
@@ -188,7 +188,7 @@
 	// when we're in homestead this also counts for code storage gas errors.
 	if err != nil {
 		evm.StateDB.RevertToSnapshot(snapshot)
-		if err != errExecutionReverted {
+		if err != ErrExecutionReverted {
 			contract.UseGas(contract.Gas)
 		}
 	}
@@ -229,7 +229,7 @@
 	ret, err = run(evm, contract, input)
 	if err != nil {
 		evm.StateDB.RevertToSnapshot(snapshot)
-		if err != errExecutionReverted {
+		if err != ErrExecutionReverted {
 			contract.UseGas(contract.Gas)
 		}
 	}
@@ -262,7 +262,7 @@
 	ret, err = run(evm, contract, input)
 	if err != nil {
 		evm.StateDB.RevertToSnapshot(snapshot)
-		if err != errExecutionReverted {
+		if err != ErrExecutionReverted {
 			contract.UseGas(contract.Gas)
 		}
 	}
@@ -305,7 +305,7 @@
 	ret, err = run(evm, contract, input)
 	if err != nil {
 		evm.StateDB.RevertToSnapshot(snapshot)
-		if err != errExecutionReverted {
+		if err != ErrExecutionReverted {
 			contract.UseGas(contract.Gas)
 		}
 	}
@@ -377,7 +377,7 @@
 	// when we're in homestead this also counts for code storage gas errors.
 	if maxCodeSizeExceeded || (err != nil && (evm.ChainConfig().IsHomestead(evm.BlockNumber) || err != ErrCodeStoreOutOfGas)) {
 		evm.StateDB.RevertToSnapshot(snapshot)
-		if err != errExecutionReverted {
+		if err != ErrExecutionReverted {
 			contract.UseGas(contract.Gas)
 		}
 	}
--- core/state_transition.go	(revision 744428cb03ea8de8f219708f57d2e197acb6689b)
+++ core/state_transition.go	(date 1524449729000)
@@ -220,6 +220,10 @@
 		if vmerr == vm.ErrInsufficientBalance {
 			return nil, 0, false, vmerr
 		}
+
+		if vmerr == vm.ErrExecutionReverted {
+			err = vmerr
+		}
 	}
 	st.refundGas()
 	st.state.AddBalance(st.evm.Coinbase, new(big.Int).Mul(new(big.Int).SetUint64(st.gasUsed()), st.gasPrice))
--- accounts/abi/bind/backends/simulated.go	(revision 744428cb03ea8de8f219708f57d2e197acb6689b)
+++ accounts/abi/bind/backends/simulated.go	(date 1524449729000)
@@ -223,6 +223,8 @@
 		lo  uint64 = params.TxGas - 1
 		hi  uint64
 		cap uint64
+
+		revert  []byte
 	)
 	if call.Gas >= params.TxGas {
 		hi = call.Gas
@@ -236,14 +238,28 @@
 		call.Gas = gas
 
 		snapshot := b.pendingState.Snapshot()
-		_, _, failed, err := b.callContract(ctx, call, b.pendingBlock, b.pendingState)
+		res, _, failed, err := b.callContract(ctx, call, b.pendingBlock, b.pendingState)
 		b.pendingState.RevertToSnapshot(snapshot)
 
 		if err != nil || failed {
+			if err == vm.ErrExecutionReverted {
+				revert = res
+			}
 			return false
 		}
 		return true
 	}
+
+	// Test the cap first to avoid searching if the maximum won't work
+	if !executable(cap) {
+		if len(revert) > 0 {
+			return 0, vm.ErrRevertedTransaction{
+				Ret: revert,
+			}
+		}
+		return 0, errGasEstimationFailed
+	}
+
 	// Execute the binary search and hone in on an executable gas limit
 	for lo+1 < hi {
 		mid := (hi + lo) / 2
@@ -253,12 +269,7 @@
 			hi = mid
 		}
 	}
-	// Reject the transaction as invalid if it still fails at the highest allowance
-	if hi == cap {
-		if !executable(hi) {
-			return 0, errGasEstimationFailed
-		}
-	}
+
 	return hi, nil
 }
 
--- core/vm/instructions.go	(revision 744428cb03ea8de8f219708f57d2e197acb6689b)
+++ core/vm/instructions.go	(date 1524449729000)
@@ -33,7 +33,6 @@
 	tt255                    = math.BigPow(2, 255)
 	errWriteProtection       = errors.New("evm: write protection")
 	errReturnDataOutOfBounds = errors.New("evm: return data out of bounds")
-	errExecutionReverted     = errors.New("evm: execution reverted")
 	errMaxCodeSizeExceeded   = errors.New("evm: max code size exceeded")
 )
 
@@ -659,7 +658,7 @@
 	contract.Gas += returnGas
 	evm.interpreter.intPool.put(value, offset, size)
 
-	if suberr == errExecutionReverted {
+	if suberr == ErrExecutionReverted {
 		return res, nil
 	}
 	return nil, nil
@@ -685,7 +684,7 @@
 	} else {
 		stack.push(evm.interpreter.intPool.get().SetUint64(1))
 	}
-	if err == nil || err == errExecutionReverted {
+	if err == nil || err == ErrExecutionReverted {
 		memory.Set(retOffset.Uint64(), retSize.Uint64(), ret)
 	}
 	contract.Gas += returnGas
@@ -714,7 +713,7 @@
 	} else {
 		stack.push(evm.interpreter.intPool.get().SetUint64(1))
 	}
-	if err == nil || err == errExecutionReverted {
+	if err == nil || err == ErrExecutionReverted {
 		memory.Set(retOffset.Uint64(), retSize.Uint64(), ret)
 	}
 	contract.Gas += returnGas
@@ -739,7 +738,7 @@
 	} else {
 		stack.push(evm.interpreter.intPool.get().SetUint64(1))
 	}
-	if err == nil || err == errExecutionReverted {
+	if err == nil || err == ErrExecutionReverted {
 		memory.Set(retOffset.Uint64(), retSize.Uint64(), ret)
 	}
 	contract.Gas += returnGas
@@ -764,7 +763,7 @@
 	} else {
 		stack.push(evm.interpreter.intPool.get().SetUint64(1))
 	}
-	if err == nil || err == errExecutionReverted {
+	if err == nil || err == ErrExecutionReverted {
 		memory.Set(retOffset.Uint64(), retSize.Uint64(), ret)
 	}
 	contract.Gas += returnGas
--- core/vm/errors.go	(revision 744428cb03ea8de8f219708f57d2e197acb6689b)
+++ core/vm/errors.go	(date 1524449729000)
@@ -16,7 +16,11 @@
 
 package vm
 
-import "errors"
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+)
 
 var (
 	ErrOutOfGas                 = errors.New("out of gas")
@@ -25,4 +29,33 @@
 	ErrTraceLimitReached        = errors.New("the number of logs reached the specified limit")
 	ErrInsufficientBalance      = errors.New("insufficient balance for transfer")
 	ErrContractAddressCollision = errors.New("contract address collision")
+	ErrExecutionReverted        = errors.New("evm: execution reverted")
 )
+
+// ErrRevertedTransaction represents an error caused by a reverted execution at the highest gas level.
+type ErrRevertedTransaction struct {
+	Ret []byte
+}
+
+// Error returns a structured error message.
+func (e ErrRevertedTransaction) Error() string {
+	if msg := e.Message(); msg != "" {
+		return fmt.Sprintf("transaction reverted with message \"%s\"", msg)
+	}
+	return "transaction reverted"
+}
+
+// Message returns the string "message" portion of the revert operation (if supplied).
+func (e ErrRevertedTransaction) Message() string {
+	// Not sure what the previous 68 bytes represent, but they may also need a method to extract data?
+	// 4 bytes = unknown uint32?
+	// 16 bytes = empty?
+	// 16 bytes = " "?
+	// 4 bytes = uint32 message length
+	// *16 bytes = message
+	if len(e.Ret) > 68 {
+		n := binary.BigEndian.Uint32(e.Ret[64:68])
+		return string(e.Ret[68:68+n])
+	}
+	return ""
+}