Set free'd pointers to NULL whenever they are not reassigned immediat…

…ely after

cJSON.c

@@ -263,10 +263,12 @@ CJSON_PUBLIC(void) cJSON_Delete(cJSON *item)
  if (!(item->type & cJSON_IsReference) && (item->valuestring != NULL))
  {
  global_hooks.deallocate(item->valuestring);
+ item->valuestring = NULL;
  }
  if (!(item->type & cJSON_StringIsConst) && (item->string != NULL))
  {
  global_hooks.deallocate(item->string);
+ item->string = NULL;
  }
  global_hooks.deallocate(item);
  item = next;
@@ -894,6 +896,7 @@ static cJSON_bool parse_string(cJSON * const item, parse_buffer * const input_bu
  if (output != NULL)
  {
  input_buffer->hooks.deallocate(output);
+ output = NULL;
  }
 
  if (input_pointer != NULL)
@@ -1236,6 +1239,7 @@ static unsigned char *print(const cJSON * const item, cJSON_bool format, const i
 
  /* free the buffer */
  hooks->deallocate(buffer->buffer);
+ buffer->buffer = NULL;
  }
 
  return printed;
@@ -1244,11 +1248,13 @@ static unsigned char *print(const cJSON * const item, cJSON_bool format, const i
  if (buffer->buffer != NULL)
  {
  hooks->deallocate(buffer->buffer);
+ buffer->buffer = NULL;
  }
 
  if (printed != NULL)
  {
  hooks->deallocate(printed);
+ printed = NULL;
  }
 
  return NULL;
@@ -1289,6 +1295,7 @@ CJSON_PUBLIC(char *) cJSON_PrintBuffered(const cJSON *item, int prebuffer, cJSON
  if (!print_value(item, &p))
  {
  global_hooks.deallocate(p.buffer);
+ p.buffer = NULL;
  return NULL;
  }
 
@@ -3132,4 +3139,5 @@ CJSON_PUBLIC(void *) cJSON_malloc(size_t size)
 CJSON_PUBLIC(void) cJSON_free(void *object)
 {
  global_hooks.deallocate(object);
+ object = NULL;
 }