Sortierung nach levels fuer Pressure-ZAxis (patch from Thomas Jahns)

src/varscan.c

@@ -2,6 +2,7 @@
 #  include "config.h"
 #endif
 
+#include <stdbool.h>
 #include <string.h>
 #include <math.h>
 
@@ -538,34 +539,36 @@ void cdi_generate_vars(stream_t *streamptr)
 
       if ( nlevels > 1 )
 	{
-	  int linc = FALSE, ldec = FALSE, lsort = FALSE;
-	  /* check increasing of levels */
-	  for ( levelID = 1; levelID < nlevels; levelID++ )
-	    if ( dlevels[levelID] < dlevels[levelID-1] ) break;
-
-	  if ( levelID == nlevels ) linc = TRUE;
-
-          /* check decreasing of levels */
+          bool linc = false, ldec = false, lsort = false;
           for ( levelID = 1; levelID < nlevels; levelID++ )
-            if ( dlevels[levelID] > dlevels[levelID-1] ) break;
-
-          if ( levelID == nlevels ) ldec = TRUE;
-
-	  if ( linc == FALSE )
-	    {
-              if ( ldec == FALSE && zaxistype == ZAXIS_PRESSURE )
-                {
-		  qsort(vartable[varid].levelTable, nlevels, sizeof(leveltable_t), cmpLevelTableInv);
-                  lsort = TRUE;
-                }
-              else if ( ldec == FALSE ||
-		   zaxistype == ZAXIS_HYBRID ||
-		   zaxistype == ZAXIS_DEPTH_BELOW_LAND )
-		{
-		  qsort(vartable[varid].levelTable, nlevels, sizeof(leveltable_t), cmpLevelTable);
-                  lsort = TRUE;
-		}
-	    }
+            {
+              /* check increasing of levels */
+              linc &= (dlevels[levelID] > dlevels[levelID-1]);
+              /* check decreasing of levels */
+              ldec &= (dlevels[levelID] < dlevels[levelID-1]);
+            }
+          /*
+           * always sort pressure z-axis to ensure
+           * vartable[varid].levelTable[levelID1].level1 < vartable[varid].levelTable[levelID2].level1 <=> levelID1 > levelID2
+           * unless already sorted in decreasing order
+           */
+          if ( !ldec && zaxistype == ZAXIS_PRESSURE )
+            {
+              qsort(vartable[varid].levelTable, (size_t)nlevels, sizeof(leveltable_t), cmpLevelTableInv);
+              lsort = true;
+            }
+          /*
+           * always sort hybrid and depth-below-land z-axis to ensure
+           * vartable[varid].levelTable[levelID1].level1 < vartable[varid].levelTable[levelID2].level1 <=> levelID1 < levelID2
+           * unless already sorted in increasing order
+           */
+          else if ( (!linc && !ldec) ||
+                    zaxistype == ZAXIS_HYBRID ||
+                    zaxistype == ZAXIS_DEPTH_BELOW_LAND )
+            {
+              qsort(vartable[varid].levelTable, (size_t)nlevels, sizeof(leveltable_t), cmpLevelTable);
+              lsort = true;
+            }
 
           if ( lsort )
             {
@@ -587,7 +590,7 @@ void cdi_generate_vars(stream_t *streamptr)
 	  dlevels2 = (double *) malloc(nlevels*sizeof(double));
 	  for ( levelID = 0; levelID < nlevels; levelID++ )
 	    dlevels2[levelID] = level_sf*vartable[varid].levelTable[levelID].level2;
-	}
+        }
 
       char *unitptr = cdiUnitNamePtr(vartable[varid].level_unit);
       zaxisID = varDefZaxis(vlistID, zaxistype, nlevels, dlevels, lbounds, dlevels1, dlevels2,