Update aws-sdk-go/service/dynamodb/dynamodbattribute (#4744)

Fixes #4721, Fixes #4742

vendor/github.com/aws/aws-sdk-go/service/dynamodb/dynamodbattribute/decode.go

@@ -1,6 +1,7 @@
 package dynamodbattribute
 
 import (
+	"encoding/base64"
 	"fmt"
 	"reflect"
 	"strconv"
@@ -538,6 +539,16 @@ func (d *Decoder) decodeString(s *string, v reflect.Value, fieldTag tag) error {
 	switch v.Kind() {
 	case reflect.String:
 		v.SetString(*s)
+	case reflect.Slice:
+		// To maintain backwards compatibility with the ConvertFrom family of methods
+		// which converted []byte into base64-encoded strings if the input was typed
+		if v.Type() == byteSliceType {
+			decoded, err := base64.StdEncoding.DecodeString(*s)
+			if err != nil {
+				return &UnmarshalError{Err: err, Value: "string", Type: v.Type()}
+			}
+			v.SetBytes(decoded)
+		}
 	case reflect.Interface:
 		// Ensure type aliasing is handled properly
 		v.Set(reflect.ValueOf(*s).Convert(v.Type()))

vendor/github.com/aws/aws-sdk-go/service/dynamodb/dynamodbattribute/doc.go

@@ -81,7 +81,7 @@
 // The ConvertTo, ConvertToList, ConvertToMap, ConvertFrom, ConvertFromMap
 // and ConvertFromList methods have been deprecated. The Marshal and Unmarshal
 // functions should be used instead. The ConvertTo|From marshallers do not
-// support BinarySet, NumberSet, nor StringSets, and will incorrect marshal
+// support BinarySet, NumberSet, nor StringSets, and will incorrectly marshal
 // binary data fields in structs as base64 strings.
 //
 // The Marshal and Unmarshal functions correct this behavior, and removes
@@ -91,5 +91,11 @@
 // replaced with have been replaced with dynamodbattribute.Marshaler and
 // dynamodbattribute.Unmarshaler interfaces.
 //
+// The Unmarshal functions are backwards compatible with data marshalled by
+// ConvertTo*, but the reverse is not true: objects marshalled using Marshal
+// are not necessarily usable by ConvertFrom*. This backward compatibility is
+// intended to assist with incremental upgrading of data following a switch
+// away from the Convert* family of functions.
+//
 // `time.Time` is marshaled as RFC3339 format.
 package dynamodbattribute