PVS-Studio warning V537 for TrinityCore

inline Vector3int32& operator+=(const Vector3int32& other) {
  x += other.x;
  y += other.y;
  z += other.y;    <<<---
  return *this;
}

This suspicious code was found in TrinityCore project by PVS-Studio static code analyzer.
Warning message is:
V537 Consider reviewing the correctness of 'y' item's usage. g3dlib vector3int32.h 77

PVS-Studio is a static analyzer for detecting bugs in the source code of applications written in C, C++, C++11, C++/CX. Site: http://www.viva64.com/en/pvs-studio/