From 3e632a49ee39102484c9f16abd3bbac320519265 Mon Sep 17 00:00:00 2001
From: Krishna Srinivas <krishna@minio.io>
Date: Wed, 13 Sep 2017 17:27:19 -0700
Subject: [PATCH] In gateway mode "continuation-token" will not contain
 "prefix" (#4911)

fixes #4900
---
 cmd/bucket-handlers-listobjects.go | 20 ++++++++++++++++++++
 cmd/gateway-handlers.go            |  2 +-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/cmd/bucket-handlers-listobjects.go b/cmd/bucket-handlers-listobjects.go
index d69666d53..6389d3034 100644
--- a/cmd/bucket-handlers-listobjects.go
+++ b/cmd/bucket-handlers-listobjects.go
@@ -51,6 +51,26 @@ func validateListObjectsArgs(prefix, marker, delimiter string, maxKeys int) APIE
 	return ErrNone
 }
 
+// Validate all the ListObjectsV2 query arguments, returns an APIErrorCode
+// if one of the args do not meet the required conditions.
+// Special conditions required by Minio server are as below
+// - delimiter if set should be equal to '/', otherwise the request is rejected.
+func validateGatewayListObjectsV2Args(prefix, marker, delimiter string, maxKeys int) APIErrorCode {
+	// Max keys cannot be negative.
+	if maxKeys < 0 {
+		return ErrInvalidMaxKeys
+	}
+
+	/// Minio special conditions for ListObjects.
+
+	// Verify if delimiter is anything other than '/', which we do not support.
+	if delimiter != "" && delimiter != "/" {
+		return ErrNotImplemented
+	}
+
+	return ErrNone
+}
+
 // ListObjectsV2Handler - GET Bucket (List Objects) Version 2.
 // --------------------------
 // This implementation of the GET operation returns some or all (up to 1000)
diff --git a/cmd/gateway-handlers.go b/cmd/gateway-handlers.go
index 144d7144b..017457b3d 100644
--- a/cmd/gateway-handlers.go
+++ b/cmd/gateway-handlers.go
@@ -800,7 +800,7 @@ func (api gatewayAPIHandlers) ListObjectsV2Handler(w http.ResponseWriter, r *htt
 
 	// 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 {
+	if s3Error := validateGatewayListObjectsV2Args(prefix, marker, delimiter, maxKeys); s3Error != ErrNone {
 		writeErrorResponse(w, s3Error, r.URL)
 		return
 	}