update minimum gas price to be 1 (#515)

* update minimum gas price to be 1

* update changelog

CHANGELOG.md

@@ -51,12 +51,14 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (`x/evm`) [\#458](https://github.com/ChainSafe/ethermint/pull/458) Define parameter for token denomination used for the EVM module.
 * (`x/evm`) [\#443](https://github.com/ChainSafe/ethermint/issues/443) Support custom Ethereum `ChainConfig` params.
 * (types) [\#434](https://github.com/ChainSafe/ethermint/issues/434) Update default denomination to Atto Photon (`aphoton`).
+* (types) [\#515](https://github.com/ChainSafe/ethermint/pull/515) Update minimum gas price to be 1.
 
 ### Bug Fixes
 
 * (types) [\#507](https://github.com/ChainSafe/ethermint/pull/507) Fix hardcoded `aphoton` on `EthAccount` balance getter and setter.
 * (`x/evm`) [\#496](https://github.com/ChainSafe/ethermint/pull/496) Fix bugs on `journal.revert` and `CommitStateDB.Copy`.
 * (types) [\#480](https://github.com/ChainSafe/ethermint/pull/480) Update [BIP44](https://github.com/bitcoin/bips/blob/master/bip-0044.mediawiki) coin type to `60` to satisfy [EIP84](https://github.com/ethereum/EIPs/issues/84).
+* (types) [\#513](https://github.com/ChainSafe/ethermint/pull/513) Fix simulated transaction bug that was causing a consensus error by unintentionally affecting the state.
 
 ## [v0.1.0] - 2020-08-23
 

x/evm/types/msg.go

@@ -82,8 +82,12 @@ func (msg MsgEthermint) GetSignBytes() []byte {
 
 // ValidateBasic runs stateless checks on the message
 func (msg MsgEthermint) ValidateBasic() error {
+	if msg.Price.IsZero() {
+		return sdkerrors.Wrapf(types.ErrInvalidValue, "gas price cannot be 0")
+	}
+
 	if msg.Price.Sign() == -1 {
-		return sdkerrors.Wrapf(types.ErrInvalidValue, "price cannot be negative %s", msg.Price)
+		return sdkerrors.Wrapf(types.ErrInvalidValue, "gas price cannot be negative %s", msg.Price)
 	}
 
 	// Amount can be 0
@@ -185,8 +189,12 @@ func (msg MsgEthereumTx) Type() string { return TypeMsgEthereumTx }
 // ValidateBasic implements the sdk.Msg interface. It performs basic validation
 // checks of a Transaction. If returns an error if validation fails.
 func (msg MsgEthereumTx) ValidateBasic() error {
+	if msg.Data.Price.Cmp(big.NewInt(0)) == 0 {
+		return sdkerrors.Wrapf(types.ErrInvalidValue, "gas price cannot be 0")
+	}
+
 	if msg.Data.Price.Sign() == -1 {
-		return sdkerrors.Wrapf(types.ErrInvalidValue, "price cannot be negative %s", msg.Data.Price)
+		return sdkerrors.Wrapf(types.ErrInvalidValue, "gas price cannot be negative %s", msg.Data.Price)
 	}
 
 	// Amount can be 0