PVS-Studio warning V528 for Snes9x

bool RegisterExt(TCHAR *ext) {
  LONG  regResult;
  TCHAR  szRegKey[PATH_MAX];
  TCHAR  szExePath[PATH_MAX];
  TCHAR   *szExeName;
  HKEY  hKey;

  if (!ext || ext==TEXT('\0'))
    return false;
  ....
}

This suspicious code was found in Snes9x project by PVS-Studio static code analyzer.
Warning message is:
V528 It is odd that pointer to 'wchar_t' type is compared with the L'\0' value. Probably meant: *ext == L'\0'. wsnes9x.cpp 6952

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