Merge fixes from trunk.

src/nvcore/Ptr.h

@@ -43,8 +43,11 @@ public:
 
 	/** Delete owned pointer and assign new one. */
 	void operator=( T * p ) {
-		delete m_ptr;
+		if (p != m_ptr)
-		m_ptr = p;
+		{
+			delete m_ptr;
+			m_ptr = p;
+		}
 	}
 
 	/** Member access. */
@@ -249,14 +252,14 @@ public:
 		/** -> operator. */
 		BaseClass * operator -> () const
 		{
-			piCheck( m_ptr != NULL );
+			nvCheck( m_ptr != NULL );
 			return m_ptr;
 		}
 
 		/** * operator. */
 		BaseClass & operator*() const
 		{
-			piCheck( m_ptr != NULL );
+			nvCheck( m_ptr != NULL );
 			return *m_ptr;
 		}