fix: listobjects return empty response for invalid prefix/marker (#5425)

Currently minio server returns a NotImplemented error when marker
is not common with prefix. Instead, return an empty ListObjectsResponse

cmd/admin-handlers_test.go

@@ -696,7 +696,7 @@ func TestValidateHealQueryParams(t *testing.T) {
 			marker:    "notmatchingmarker",
 			delimiter: "/",
 			maxKeys:   "10",
-			apiErr:    ErrNotImplemented,
+			apiErr:    ErrInvalidPrefixMarker,
 		},
 		// 8. Invalid params with unsupported delimiter.
 		{
@@ -812,7 +812,7 @@ func TestListObjectsHealHandler(t *testing.T) {
 			marker:     "notmatchingmarker",
 			delimiter:  "/",
 			maxKeys:    "10",
-			statusCode: getAPIError(ErrNotImplemented).HTTPStatusCode,
+			statusCode: getAPIError(ErrInvalidPrefixMarker).HTTPStatusCode,
 		},
 		// 8. Invalid params with unsupported delimiter.
 		{

cmd/api-errors.go

@@ -124,6 +124,7 @@ const (
 	ErrUnsupportedMetadata
 	ErrMaximumExpires
 	ErrSlowDown
+	ErrInvalidPrefixMarker
 	// Add new error codes here.
 
 	// Server-Side-Encryption (with Customer provided key) related API errors.
@@ -524,6 +525,12 @@ var errorCodeResponse = map[APIErrorCode]APIError{
 		Description:    "Please reduce your request",
 		HTTPStatusCode: http.StatusServiceUnavailable,
 	},
+	ErrInvalidPrefixMarker: {
+		Code:           "InvalidPrefixMarker",
+		Description:    "Invalid marker prefix combination",
+		HTTPStatusCode: http.StatusBadRequest,
+	},
+
 	// FIXME: Actual XML error response also contains the header which missed in list of signed header parameters.
 	ErrUnsignedHeaders: {
 		Code:           "AccessDenied",

cmd/bucket-handlers-listobjects.go

@@ -44,7 +44,7 @@ func validateListObjectsArgs(prefix, marker, delimiter string, maxKeys int) APIE
 	if marker != "" {
 		// Marker not common with prefix is not implemented.
 		if !hasPrefix(marker, prefix) {
-			return ErrNotImplemented
+			return ErrInvalidPrefixMarker
 		}
 	}
 	// Success.
@@ -107,9 +107,18 @@ func (api objectAPIHandlers) ListObjectsV2Handler(w http.ResponseWriter, r *http
 	// Validate the query params before beginning to serve the request.
 	// fetch-owner is not validated since it is a boolean
 	if s3Error := validateListObjectsArgs(prefix, marker, delimiter, maxKeys); s3Error != ErrNone {
+		// return empty response if invalid marker
+		//TODO: avoid this pattern when moving to errors package
+		if s3Error == ErrInvalidPrefixMarker {
+			listObjectsInfo := ListObjectsInfo{}
+			response := generateListObjectsV2Response(bucket, prefix, token, marker, startAfter, delimiter, fetchOwner, listObjectsInfo.IsTruncated, maxKeys, listObjectsInfo.Objects, listObjectsInfo.Prefixes)
+			writeSuccessResponseXML(w, encodeResponse(response))
+			return
+		}
 		writeErrorResponse(w, s3Error, r.URL)
 		return
 	}
+
 	// Inititate a list objects operation based on the input params.
 	// On success would return back ListObjectsInfo object to be
 	// marshalled into S3 compatible XML header.
@@ -151,6 +160,13 @@ func (api objectAPIHandlers) ListObjectsV1Handler(w http.ResponseWriter, r *http
 
 	// Validate all the query params before beginning to serve the request.
 	if s3Error := validateListObjectsArgs(prefix, marker, delimiter, maxKeys); s3Error != ErrNone {
+		// return empty response if invalid marker
+		//TODO: avoid this pattern when moving to errors package
+		if s3Error == ErrInvalidPrefixMarker {
+			response := generateListObjectsV1Response(bucket, prefix, marker, delimiter, maxKeys, ListObjectsInfo{})
+			writeSuccessResponseXML(w, encodeResponse(response))
+			return
+		}
 		writeErrorResponse(w, s3Error, r.URL)
 		return
 	}