Ensures that transactions cannot be confirmed if gas limit is below 21000. (#6625)

ui/app/components/app/gas-customization/gas-modal-page-container/gas-modal-page-container.container.js

@@ -201,7 +201,20 @@ const mapDispatchToProps = dispatch => {
 }
 
 const mergeProps = (stateProps, dispatchProps, ownProps) => {
-  const { gasPriceButtonGroupProps, isConfirm, txId, isSpeedUp, insufficientBalance, maxModeOn, customGasPrice, customGasTotal, balance, selectedToken, tokenBalance} = stateProps
+  const {
+    gasPriceButtonGroupProps,
+    isConfirm,
+    txId,
+    isSpeedUp,
+    insufficientBalance,
+    maxModeOn,
+    customGasPrice,
+    customGasTotal,
+    balance,
+    selectedToken,
+    tokenBalance,
+    customGasLimit,
+  } = stateProps
   const {
     updateCustomGasPrice: dispatchUpdateCustomGasPrice,
     hideGasButtonGroup: dispatchHideGasButtonGroup,
@@ -251,7 +264,7 @@ const mergeProps = (stateProps, dispatchProps, ownProps) => {
         dispatchHideSidebar()
       }
     },
-    disableSave: insufficientBalance || (isSpeedUp && customGasPrice === 0),
+    disableSave: insufficientBalance || (isSpeedUp && customGasPrice === 0) || customGasLimit < 21000,
   }
 }
 

ui/app/pages/confirm-transaction-base/confirm-transaction-base.component.js

@@ -9,6 +9,7 @@ import { DEFAULT_ROUTE, CONFIRM_TRANSACTION_ROUTE } from '../../helpers/constant
 import {
   INSUFFICIENT_FUNDS_ERROR_KEY,
   TRANSACTION_ERROR_KEY,
+  GAS_LIMIT_TOO_LOW_ERROR_KEY,
 } from '../../helpers/constants/error-keys'
 import { CONFIRMED_STATUS, DROPPED_STATUS } from '../../helpers/constants/transactions'
 import UserPreferencedCurrencyDisplay from '../../components/app/user-preferenced-currency-display'
@@ -134,6 +135,7 @@ export default class ConfirmTransactionBase extends Component {
           value: amount,
         } = {},
       } = {},
+      customGas,
     } = this.props
 
     const insufficientBalance = balance && !isBalanceSufficient({
@@ -150,6 +152,13 @@ export default class ConfirmTransactionBase extends Component {
       }
     }
 
+    if (customGas.gasLimit < 21000) {
+      return {
+        valid: false,
+        errorKey: GAS_LIMIT_TOO_LOW_ERROR_KEY,
+      }
+    }
+
     if (simulationFails) {
       return {
         valid: true,