Re: github issue #373

Github issue #152
requested that "orphaned" DAS attributes be included in the netcdf
metadata as global variables. The term orphaned here meant that
they were not connected to any variable in the DDS.
This was done in pull request #164

However, some servers (e.g. Thredds) include attributes for variables not
specified in a constraint expression, but which exist in the full DDS.
So I was adding these to the set of global attributes, but in retrospect
this should not have been done: they should have been elided.

Solution: modify oc2 code to be more distriminatory about
which orphaned attributes to include.

libdap2/ncd2dispatch.c

@@ -769,6 +769,8 @@ fprintf(stderr,"buildvars.candidate=|%s|\n",var->ncfullname);
  	    }
         }
 
+
+
 	definename = getdefinename(var);
 
 #ifdef DEBUG1

oc2/ocnode.c

@@ -6,22 +6,14 @@
 #include "occompile.h"
 #include "ocdebug.h"
 
-/* If enabled, then DAS attributes that cannot
-   be connected to any variable will be shown as
-   global attributes. No obvious reason to enable
-   except possibly for debugging purposes.
-*/
-#undef SHOWORPHAN
-
 static const unsigned int MAX_UINT = 0xffffffff;
 
 static OCerror mergedas1(OCnode* dds, OCnode* das);
 static OCerror mergedods1(OCnode* dds, OCnode* das);
 static char* pathtostring(OClist* path, char* separator);
 static void computefullname(OCnode* node);
-#ifdef SHOWORPHAN
 static OCerror mergeother1(OCnode* root, OCnode* das);
-#endif
+static OCerror mergeother(OCnode* ddsroot, OClist* dasnodes);
 
 /* Process ocnodes to fix various semantic issues*/
 void
@@ -344,15 +336,13 @@ ocddsdasmerge(OCstate* state, OCnode* dasroot, OCnode* ddsroot)
 	mergedods1(ddsroot,das);
     }
 
-#ifdef SHOWORPHAN
     /* 6. Assign other orphan attributes, which means
-	  construct their full name and assign as a global attribute. */
-    for(i=0;i<oclistlength(dasnodes);i++) {
-	OCnode* das = (OCnode*)oclistget(dasnodes,i);
-	if(das == NULL) continue;
-	mergeother1(ddsroot, das);
-    }
-#endif
+	  construct their full name and assign as a global attribute.
+	  This is complicated because some servers (e.g. thredds) returns
+          attributes for variables that were not referenced in the DDS.
+          These we continue to suppress.
+     */
+    mergeother(ddsroot,dasnodes);
 
 done:
     /* cleanup*/
@@ -374,6 +364,11 @@ mergedas1(OCnode* dds, OCnode* das)
     for(i=0;i<oclistlength(das->subnodes);i++) {
 	OCnode* attnode = (OCnode*)oclistget(das->subnodes,i);
 	if(attnode->octype == OC_Attribute) {
+	    if(dds->octype == OC_Atomic
+		|| dds->octype == OC_Sequence
+		|| dds->octype == OC_Structure
+		|| dds->octype == OC_Grid)
+	        attnode->att.var = dds;
 	    OCattribute* att = makeattribute(attnode->name,
 						attnode->etype,
 						attnode->att.values);
@@ -418,7 +413,19 @@ mergedods1(OCnode* dds, OCnode* dods)
     return OCTHROW(stat);
 }
 
-#ifdef SHOWORPHAN
+static OCerror
+mergeother(OCnode* ddsroot, OClist* dasnodes)
+{
+    OCerror stat = OC_NOERR;
+    int i;
+    for(i=0;i<oclistlength(dasnodes);i++) {
+	OCnode* das = (OCnode*)oclistget(dasnodes,i);
+	if(das == NULL) continue;
+	if((stat = mergeother1(ddsroot, das))) break;
+    }
+    return stat;
+}
+
 static OCerror
 mergeother1(OCnode* root, OCnode* das)
 {
@@ -428,6 +435,9 @@ mergeother1(OCnode* root, OCnode* das)
     OCASSERT(root != NULL);
     if(root->attributes == NULL) root->attributes = oclistnew();
 
+    /* Only include if this is not connected to a variable */
+    if(das->att.var != NULL) goto done;
+
     if(das->octype == OC_Attribute) {
         /* compute the full name of this attribute */
         computefullname(das);
@@ -444,9 +454,9 @@ mergeother1(OCnode* root, OCnode* das)
 	}	
     } else
 	stat = OC_EDAS;
+done:
     return OCTHROW(stat);
 }
-#endif
 
 static void
 ocuncorrelate(OCnode* root)

oc2/ocnode.h

@@ -37,6 +37,7 @@ typedef struct OCattinfo {
     int isglobal; /* is this supposed to be a global attribute set?*/
     int isdods;   /* is this a global DODS_XXX  attribute set */
     OClist* values; /* oclist<char*>*/
+    struct OCnode* var; /* containing var else null */
 } OCattinfo;
 
 /*! Specifies the OCnode. */