[svn-r15395] When an attribute was opened twice and data was written with one of the handles,

the file didn't have the data.  It happened because each handle had its own
object structure, and the empty one overwrote the data with fill value.  This is
fixed by making some attribute information like the data be shared in the
attribute structure.

Tested on smirom, kagiso, and linew.

c++/src/H5DataSpace.cpp

@@ -593,9 +593,6 @@ void DataSpace::setId(const hid_t new_id)
     }
    // reset object's id to the given id
    id = new_id;
-
-   // increment the reference counter of the new id
-   incRefCount();
 }
 
 //--------------------------------------------------------------------------
@@ -615,8 +612,10 @@ void DataSpace::close()
 	{
 	    throw DataSpaceIException("DataSpace::close", "H5Sclose failed");
 	}
-	// reset the id because the dataspace that it represents is now closed
-	id = 0;
+	// reset the id when the dataspace that it represents is no longer
+	// referenced
+	if (getCounter() == 0)
+	    id = 0;
     }
 }
 
@@ -632,16 +631,10 @@ void DataSpace::close()
 //--------------------------------------------------------------------------
 DataSpace::~DataSpace()
 {
-    int counter = getCounter(id);
-    if (counter > 1)
-	decRefCount(id);
-    else if (counter == 1)
-    {
-	try {
-	    close();
-	} catch (Exception close_error) {
-	    cerr << "DataSpace::~DataSpace - " << close_error.getDetailMsg() << endl;
-	}
+    try {
+	close();
+    } catch (Exception close_error) {
+	cerr << "DataSpace::~DataSpace - " << close_error.getDetailMsg() << endl;
     }
 }