PVS-Studio warning V501 for PHP

static enum
entity_charset determine_charset(char *charset_hint TSRMLS_DC)
{
  ....
  if ((len == 4) /* sizeof (none|auto|pass) */ && //<==
    (!memcmp("pass", charset_hint, 4) ||
     !memcmp("auto", charset_hint, 4) ||          //<==
     !memcmp("auto", charset_hint, 4)))           //<==
  {
       charset_hint = NULL;
      len = 0;
  }
  ....
}

This suspicious code was found in PHP project by PVS-Studio static code analyzer.
Warning message is:
V501 There are identical sub-expressions '!memcmp("auto", charset_hint, 4)' to the left and to the right of the '||' operator. html.c 396

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