fix: reject the start-after query in ListObjects (V1)

Fixes #2004

s3api/controllers/bucket-get.go

@@ -22,6 +22,7 @@ import (
 	"github.com/gofiber/fiber/v3"
 	"github.com/versity/versitygw/auth"
 	"github.com/versity/versitygw/s3api/utils"
+	"github.com/versity/versitygw/s3err"
 	"github.com/versity/versitygw/s3response"
 )
 
@@ -614,6 +615,15 @@ func (c S3ApiController) ListObjects(ctx fiber.Ctx) (*Response, error) {
 		region = defaultRegion
 	}
 
+	// start-after is a ListObjectsV2 argument, S3 rejects it on a V1 listing
+	if ctx.Query("start-after") != "" {
+		return &Response{
+			MetaOpts: &MetaOptions{
+				BucketOwner: parsedAcl.Owner,
+			},
+		}, s3err.GetInvalidArgumentErr(s3err.InvalidArgStartAfter, "")
+	}
+
 	err := c.verifyAccess(ctx, auth.AccessOptions{
 		Acl:             parsedAcl,
 		AclPermission:   auth.PermissionRead,

s3api/controllers/bucket-get_test.go

@@ -1195,6 +1195,24 @@ func TestS3ApiController_ListObjects(t *testing.T) {
 				err: s3err.GetAPIError(s3err.ErrAccessDenied),
 			},
 		},
+		{
+			name: "start-after is not supported",
+			input: testInput{
+				locals: defaultLocals,
+				beRes:  listResult,
+				queries: map[string]string{
+					"start-after": "my-key",
+				},
+			},
+			output: testOutput{
+				response: &Response{
+					MetaOpts: &MetaOptions{
+						BucketOwner: "root",
+					},
+				},
+				err: s3err.GetInvalidArgumentErr(s3err.InvalidArgStartAfter, ""),
+			},
+		},
 		{
 			name: "invalid max keys",
 			input: testInput{