Make sharing behavior consitent with the behavior of the old backend (#…

…748)

internal/http/services/owncloud/ocs/conversions/permissions.go

@@ -41,17 +41,17 @@ const (
 )
 
 var (
-	// ErrPermissionAboveRange defines a permission specific error.
-	ErrPermissionAboveRange = fmt.Errorf("The provided permission is higher than %d", PermissionAll)
+	// ErrPermissionNotInRange defines a permission specific error.
+	ErrPermissionNotInRange = fmt.Errorf("The provided permission is not between %d and %d", PermissionInvalid, PermissionAll)
 )
 
 // NewPermissions creates a new Permissions instanz.
 // The value must be in the valid range.
 func NewPermissions(val int) (Permissions, error) {
-	if val <= int(PermissionInvalid) {
+	if val == int(PermissionInvalid) {
 		return PermissionInvalid, fmt.Errorf("permissions %d out of range %d - %d", val, PermissionRead, PermissionAll)
-	} else if int(PermissionAll) < val {
-		return PermissionInvalid, ErrPermissionAboveRange
+	} else if val < int(PermissionInvalid) || int(PermissionAll) < val {
+		return PermissionInvalid, ErrPermissionNotInRange
 	}
 	return Permissions(val), nil
 }