[svn-r26655] Purpose: Fixed HDFFV-7947

Description:
    When copy constructor or constructor that takes an existing id is invoked,
    the C ref counter stays the same but there is an extra C++ object which
    later is destroyed and may cause the HDF5 id to be closed prematurely. The
    C++ library needs to increment the ref counter in these situations, so that
    the C library will not close the id when it is still being referenced.

    However, the incrementing of ref count left some objects opened at the end
    of the program, perhaps, due to compiler's optimization on cons/destructors.    The constructor, that takes an existing id, needs to increment the counter
    but it seems that the matching destructor wasn't invoked.  The workaround
    is to have a function for each class that has "id" that only sets the id
    and not increment the ref count for the library to use in these situations.
    These functions are "friend" and not public.

    The friend functions are:
        void f_Attribute_setId(Attribute *, hid_t)
        void f_DataSet_setId(DataSet *, hid_t)
        void f_DataSpace_setId(DataSpace *, hid_t)
        void f_DataType_setId(DataType *, hid_t)
Platforms tested:
    Linux/64 (platypus)
    Linux/32 2.6 (jam gnu and Intel 15.0)
    SunOS 5.11 (emu)

1 files changed, 14 insertions, 9 deletions

diff --git a/c++/src/H5Attribute.h b/c++/src/H5Attribute.h
index f57b922..eced64e 100644
--- a/c++/src/H5Attribute.h
+++ b/c++/src/H5Attribute.h
@@ -31,6 +31,16 @@ namespace H5 {
 */
 class H5_DLLCPP Attribute : public AbstractDs, public IdComponent {
    public:
+
+	// Copy constructor: makes a copy of an existing Attribute object.
+	Attribute( const Attribute& original );
+
+	// Default constructor
+	Attribute();
+
+	// Creates a copy of an existing attribute using the attribute id
+	Attribute( const hid_t attr_id );
+
 	// Closes this attribute.
 	virtual void close();
 
@@ -70,15 +80,6 @@ class H5_DLLCPP Attribute : public AbstractDs, public IdComponent {
 	///\brief Returns this class name.
 	virtual H5std_string fromClass () const { return("Attribute"); }
 
-	// Creates a copy of an existing attribute using the attribute id
-	Attribute( const hid_t attr_id );
-
-	// Copy constructor: makes a copy of an existing Attribute object.
-	Attribute( const Attribute& original );
-
-	// Default constructor
-	Attribute();
-
 	// Gets the attribute id.
 	virtual hid_t getId() const;
 
@@ -109,6 +110,10 @@ class H5_DLLCPP Attribute : public AbstractDs, public IdComponent {
 
 	// do not inherit H5Object::renameAttr
 	void renameAttr() {}
+
+	// Friend function to set Attribute id.  For library use only.
+	friend void f_Attribute_setId(Attribute* attr, hid_t new_id);
+
 };
 #ifndef H5_NO_NAMESPACE
 }