Merge pull request #9580 from kjbracey-arm/sharedptr_reset

Fix SharedPtr::reset

platform/SharedPtr.h

@@ -145,10 +145,13 @@ class SharedPtr {
         // Clean up by decrementing counter
         decrement_counter();
 
+        _ptr = ptr;
         if (ptr != NULL) {
             // Allocate counter on the heap, so it can be shared
             _counter = new uint32_t;
             *_counter = 1;
+        } else {
+            _counter = NULL;
         }
     }
 
@@ -223,15 +226,15 @@ class SharedPtr {
     /**
      * @brief Decrement reference counter.
      * @details If count reaches zero, free counter and delete object pointed to.
+     * Does not modify our own pointers - assumption is they will be overwritten
+     * or destroyed immediately afterwards.
      */
     void decrement_counter()
     {
         if (_ptr != NULL) {
             if (core_util_atomic_decr_u32(_counter, 1) == 0) {
                 delete _counter;
-                _counter = NULL;
                 delete _ptr;
-                _ptr = NULL;
             }
         }
     }