NetCDF: Fix xyz dim order for unstructured grids without coordinates.

ChangeLog

@@ -3,6 +3,10 @@
         * using EXSE library version 1.4.1
 	* Version 1.9.6 released
 
+2018-10-08  Uwe Schulzweida
+
+	* NetCDF: Fix xyz dim order for unstructured grids without coordinates
+
 2018-09-26  Uwe Schulzweida
 
 	* Added gridInqXvalsPart() and gridInqYvalsPart() [patch from: Niklas Rber]

src/stream_cdf_i.c

@@ -3188,7 +3188,7 @@ void cdf_define_all_vars(stream_t *streamptr, int vlistID, int instID, int model
 
       const int *dimids = ncvars[ncvarid].dimids;
 
-      if ( gridInqType(gridID) == GRID_UNSTRUCTURED && ndims-iodim <= 2 && ydimid == xdimid )
+      if ( gridInqType(gridID) == GRID_UNSTRUCTURED && ndims-iodim <= 2 && (ydimid == xdimid || ydimid == CDI_UNDEFID) )
         {
           ixyz = (xdimid == dimids[ndims-1]) ? 321 : 213;
         }