service/s3/s3manager: Update S3 Upload Multipart location (#324)

Updates the Location returned value of S3 Upload's Multipart
UploadOutput type to be consistent with single part upload URL. This
update also brings the multipart upload Location inline with the S3
object URLs created by the SDK.

Fix #323
V2 Port aws/aws-sdk-go#2453

service/s3/s3manager/upload.go

@@ -583,8 +583,18 @@ func (u *multiuploader) upload(firstBuf io.ReadSeeker) (*UploadOutput, error) {
 			uploadID: u.uploadID,
 		}
 	}
+
+	// Create a presigned URL of the S3 Get Object in order to have parity with
+	// single part upload.
+	getReq := u.cfg.S3.GetObjectRequest(&s3.GetObjectInput{
+		Bucket: u.in.Bucket,
+		Key:    u.in.Key,
+	})
+	getReq.Config.Credentials = aws.AnonymousCredentials
+	uploadLocation, _, _ := getReq.PresignRequest(1)
+
 	return &UploadOutput{
-		Location:  aws.StringValue(complete.Location),
+		Location:  uploadLocation,
 		VersionID: complete.VersionId,
 		UploadID:  u.uploadID,
 	}, nil

service/s3/s3manager/upload_test.go

@@ -104,7 +104,7 @@ func TestUploadOrderMulti(t *testing.T) {
 
 	resp, err := u.Upload(&s3manager.UploadInput{
 		Bucket:               aws.String("Bucket"),
-		Key:                  aws.String("Key"),
+		Key:                  aws.String("Key - value"),
 		Body:                 bytes.NewReader(buf12MB),
 		ServerSideEncryption: s3.ServerSideEncryptionAwsKms,
 		SSEKMSKeyId:          aws.String("KmsId"),
@@ -120,8 +120,8 @@ func TestUploadOrderMulti(t *testing.T) {
 		t.Errorf("Expected %v, but received %v", expected, *ops)
 	}
 
-	if "https://location" != resp.Location {
-		t.Errorf("Expected %q, but received %q", "https://location", resp.Location)
+	if e, a := `https://endpoint/Bucket/Key%20-%20value`, resp.Location; e != a {
+		t.Errorf("Expected %q, but received %q", e, a)
 	}
 
 	if "UPLOAD-ID" != resp.UploadID {
@@ -282,7 +282,7 @@ func TestUploadOrderSingle(t *testing.T) {
 	mgr := s3manager.NewUploaderWithClient(s)
 	resp, err := mgr.Upload(&s3manager.UploadInput{
 		Bucket:               aws.String("Bucket"),
-		Key:                  aws.String("Key"),
+		Key:                  aws.String("Key - value"),
 		Body:                 bytes.NewReader(buf2MB),
 		ServerSideEncryption: s3.ServerSideEncryptionAwsKms,
 		SSEKMSKeyId:          aws.String("KmsId"),
@@ -297,8 +297,8 @@ func TestUploadOrderSingle(t *testing.T) {
 		t.Errorf("Expected %v, but received %v", vals, *ops)
 	}
 
-	if len(resp.Location) == 0 {
-		t.Error("Expected Location to not be empty")
+	if e, a := `https://endpoint/Bucket/Key%20-%20value`, resp.Location; e != a {
+		t.Errorf("Expected %q, but received %q", e, a)
 	}
 
 	if e := "VERSION-ID"; e != *resp.VersionID {