trie, accounts/abi: nits: adds err checks (#583)

Author: Darioush Jalali

accounts/abi/abi.go

@@ -365,7 +365,10 @@ func UnpackRevert(data []byte) (string, error) {
 	if !bytes.Equal(data[:4], revertSelector) {
 		return "", errors.New("invalid data for unpacking")
 	}
-	typ, _ := NewType("string", "", nil)
+	typ, err := NewType("string", "", nil)
+	if err != nil {
+		return "", err
+	}
 	unpacked, err := (Arguments{{Type: typ}}).Unpack(data[4:])
 	if err != nil {
 		return "", err

trie/stacktrie.go

@@ -151,7 +151,9 @@ func (st *StackTrie) unmarshalBinary(r io.Reader) error {
 		Val      []byte
 		Key      []byte
 	}
-	gob.NewDecoder(r).Decode(&dec)
+	if err := gob.NewDecoder(r).Decode(&dec); err != nil {
+		return err
+	}
 	st.owner = dec.Owner
 	st.nodeType = dec.NodeType
 	st.val = dec.Val
@@ -165,7 +167,9 @@ func (st *StackTrie) unmarshalBinary(r io.Reader) error {
 			continue
 		}
 		var child StackTrie
-		child.unmarshalBinary(r)
+		if err := child.unmarshalBinary(r); err != nil {
+			return err
+		}
 		st.children[i] = &child
 	}
 	return nil