Adding check inside EVM loop for errors to avoid executing contract w…

…hen it should be stopped.

state/runtime/evm/state.go

@@ -243,6 +243,13 @@ func (c *state) Run() ([]byte, error) {
 		if tracer != nil {
 			c.captureExecution(op.String(), ipCopy, gasCopy, gasCopy-c.gas)
 		}
+
+		// In case there was an error set in current instruction, let the execution trace
+		// to allow easier debugging and stop the execution.
+		if err := c.err; err != nil {
+			break
+		}
+
 		// check if stack size exceeds the max size
 		if c.stack.sp > stackSize {
 			c.exit(&runtime.StackOverflowError{StackLen: c.stack.sp, Limit: stackSize})

state/runtime/evm/state_test.go

@@ -27,6 +27,10 @@ func (c *codeHelper) push1() {
 	c.buf = append(c.buf, 0x1)
 }
 
+func (c *codeHelper) opDup() {
+	c.buf = append(c.buf, DUP16)
+}
+
 func (c *codeHelper) pop() {
 	c.buf = append(c.buf, POP)
 }
@@ -126,3 +130,20 @@ func TestOpcodeNotFound(t *testing.T) {
 	_, err := s.Run()
 	assert.Equal(t, errOpCodeNotFound, err)
 }
+
+func TestErrorHandlingStopsContractExecution(t *testing.T) {
+	code := codeHelper{}
+	code.opDup()
+	code.opDup()
+
+	s, closeFn := getState(&chain.ForksInTime{})
+	defer closeFn()
+
+	s.code = code.buf
+	s.gas = 10000
+	s.host = &mockHost{}
+
+	_, err := s.Run()
+	assert.Error(t, err, "The EVM did not handle an error")
+	assert.Equal(t, s.ip, 0, "The EVM did not executingon first error.")
+}