message: Whether or not a pointer is NULL is not a reliable check for NULL values in strings
diff: @@ -34,7 +34,7 @@ template <class T> inline bool IsNullValue(T value) {
  }
  template <> inline bool IsNullValue(const char *value) {
  - return !value || strcmp(value, NullValue<const char *>()) == 0;
  + return strcmp(value, NullValue<const char *>()) == 0;
  }
  template <> inline bool IsNullValue(char *value) {
  