Add test for NIL-UUID.

* RFC 4122 does not guarantee octet 0 to be non-zero.

app/cdi.c

@@ -33,6 +33,13 @@ int      vlistInqVarMissvalUsed(int vlistID, int varID);
 #endif
 
 
+static inline int
+cdiUUIDIsNull(const unsigned char uuid[CDI_UUID_SIZE])
+{
+  static unsigned char uuid_nil[CDI_UUID_SIZE];
+  return !memcmp(uuid, uuid_nil, CDI_UUID_SIZE);
+}
+
 #include "printinfo.h"
 
 void cdiDefTableID(int tableID);

app/printinfo.h

@@ -368,7 +368,7 @@ void printGridInfo(int vlistID)
 	}
 
       gridInqUUID(gridID, uuidOfHGrid);
-      if ( uuidOfHGrid[0] != 0 )
+      if ( !cdiUUIDIsNull(uuidOfHGrid) )
         {
           char uuidOfHGridStr[37];
           uuid2str(uuidOfHGrid, uuidOfHGridStr);
@@ -471,7 +471,7 @@ void printZaxisInfo(int vlistID)
 
           unsigned char uuidOfVGrid[CDI_UUID_SIZE];
           zaxisInqUUID(zaxisID, uuidOfVGrid);
-          if ( uuidOfVGrid[0] != 0 )
+          if ( !cdiUUIDIsNull(uuidOfVGrid) )
             {
               char uuidOfVGridStr[37];
               uuid2str(uuidOfVGrid, uuidOfVGridStr);

src/cdi_int.h

@@ -65,6 +65,8 @@ char *strdup(const char *s);
 #  include "resource_handle.h"
 #endif
 
+#include "cdi.h"
+
 
 #define check_parg(arg)  if ( arg == 0 ) Warning("Argument '" #arg "' not allocated!")
 
@@ -342,6 +344,13 @@ void  cdiInitialize(void);
 
 void uuid2str(const unsigned char *uuid, char *uuidstr);
 int str2uuid(const char *uuidstr, unsigned char *uuid);
+static inline int
+cdiUUIDIsNull(const unsigned char uuid[CDI_UUID_SIZE])
+{
+  static unsigned char uuid_nil[CDI_UUID_SIZE];
+  return !memcmp(uuid, uuid_nil, CDI_UUID_SIZE);
+}
+
 
 #define CDI_UNIT_PA   1
 #define CDI_UNIT_HPA  2

src/grid.c

@@ -137,7 +137,7 @@ void grid_init(grid_t *gridptr)
   gridptr->yunits[0]    = 0;
   gridptr->xstdname[0]  = 0;
   gridptr->ystdname[0]  = 0;
-  memset(gridptr->uuid, 0, 16);
+  memset(gridptr->uuid, 0, CDI_UUID_SIZE);
   gridptr->name         = NULL;
 }
 
@@ -2491,7 +2491,7 @@ int gridGenerate(grid_t grid)
                 gridDefNumber(gridID, number);
                 gridDefPosition(gridID, position);
               }
-            if ( grid.uuid[0] != 0 ) gridDefUUID(gridID, grid.uuid);
+            gridDefUUID(gridID, grid.uuid);
             if ( grid.reference ) gridDefReference(gridID, grid.reference);
           }
 
@@ -3326,7 +3326,7 @@ void gridPrintKernel(grid_t * gridptr, int opt, FILE *fp)
     }
 
   gridInqUUID(gridID, uuidOfHGrid);
-  if ( uuidOfHGrid[0] != 0 )
+  if ( !cdiUUIDIsNull(uuidOfHGrid) )
     {
       char uuidOfHGridStr[37];
       uuid2str(uuidOfHGrid, uuidOfHGridStr);

src/stream_cdf.c

@@ -2046,7 +2046,7 @@ void cdfDefGridUUID(stream_t *streamptr, int gridID)
   unsigned char uuidOfHGrid[CDI_UUID_SIZE];
 
   gridInqUUID(gridID, uuidOfHGrid);
-  if ( uuidOfHGrid[0] != 0 )
+  if ( !cdiUUIDIsNull(uuidOfHGrid) )
     {
       char uuidOfHGridStr[37];
       uuid2str(uuidOfHGrid, uuidOfHGridStr);
@@ -7437,10 +7437,10 @@ int cdfInqContents(stream_t *streamptr)
   char fcreftime[CDI_MAX_NAME];
   int number_of_grid_used = UNDEFID;
 
-  uuidOfHGrid[0] = 0;
-  uuidOfVGrid[0] = 0;
-  gridfile[0]    = 0;
-  fcreftime[0]   = 0;
+  memset(uuidOfHGrid, 0, CDI_UUID_SIZE);
+  memset(uuidOfVGrid, 0, CDI_UUID_SIZE);
+  gridfile[0] = 0;
+  fcreftime[0] = 0;
 
   vlistID = streamptr->vlistID;
   fileID  = streamptr->fileID;

src/varscan.c

@@ -597,7 +597,7 @@ void cdi_generate_vars(stream_t *streamptr)
         {
           if ( numberOfVerticalLevels > 0 ) zaxisDefNlevRef(zaxisID, numberOfVerticalLevels);
           if ( numberOfVerticalGrid > 0 ) zaxisDefNumber(zaxisID, numberOfVerticalGrid);
-          if ( uuidVGrid[0] != 0 ) zaxisDefUUID(zaxisID, uuidVGrid);
+          if ( !cdiUUIDIsNull(uuidVGrid) ) zaxisDefUUID(zaxisID, uuidVGrid);
         }
 
       if ( lbounds ) free(dlevels1);

src/zaxis.c

@@ -128,7 +128,7 @@ void zaxisDefaultValue(zaxis_t *zaxisptr)
   zaxisptr->vct         = NULL;
   zaxisptr->number      = 0;
   zaxisptr->nhlev       = 0;
-  zaxisptr->uuid[0]     = 0;
+  memset(zaxisptr->uuid, 0, CDI_UUID_SIZE);
 }