check node for being nil

Signed-off-by: jkoberg <jkoberg@owncloud.com>

pkg/storage/utils/decomposedfs/spaces.go

@@ -44,6 +44,7 @@ import (
 	"github.com/cs3org/reva/pkg/storage/utils/decomposedfs/xattrs"
 	"github.com/cs3org/reva/pkg/utils"
 	"github.com/google/uuid"
+	"github.com/pkg/errors"
 	"github.com/pkg/xattr"
 )
 
@@ -532,6 +533,11 @@ func (fs *Decomposedfs) createStorageSpace(ctx context.Context, spaceType, space
 }
 
 func (fs *Decomposedfs) storageSpaceFromNode(ctx context.Context, n *node.Node, spaceType, nodePath string, canListAllSpaces bool) (*provider.StorageSpace, error) {
+	if n == nil {
+		// TODO: Why is this called with nil node?
+		return nil, errors.New("can't create storage space from nil node")
+	}
+
 	user := ctxpkg.ContextMustGetUser(ctx)
 	if !canListAllSpaces {
 		ok, err := node.NewPermissions(fs.lu).HasPermission(ctx, n, func(p *provider.ResourcePermissions) bool {