function can_change_tag(PaperInfo $prow, $tag, $previndex, $index, $forceShow = null)
{
global $Conf;
if ($forceShow === ALWAYS_OVERRIDE) {
return true;
}
$rights = $this->rights($prow, $forceShow);
if (!($rights->allow_pc && ($rights->can_administer || $Conf->timePCViewPaper($prow, false)))) {
if ($this->privChair && TagInfo::has_sitewide() && (!$tag || ($t = TagInfo::defined_tag($tag)) && $t->sitewide)) {
return true;
}
return false;
}
if (!$tag) {
return true;
}
$tag = TagInfo::base($tag);
$twiddle = strpos($tag, "~");
if ($twiddle === 0 && $tag[1] === "~") {
return $rights->can_administer;
}
if ($twiddle > 0 && substr($tag, 0, $twiddle) != $this->contactId && !$rights->can_administer) {
return false;
}
if ($twiddle !== false) {
$t = TagInfo::defined_tag(substr($tag, $twiddle + 1));
return !($t && $t->vote && $index < 0);
} else {
$t = TagInfo::defined_tag($tag);
return !$t || ($rights->can_administer || $this->privChair && $t->sitewide || !$t->chair && !$t->rank) && !$t->vote && !$t->approval;
}
}
