sS gazelle_copyRuleWithNewText(S ruleID, S newText) {
  if (emptyAfterTrim(newText)) null;
  PairS p = dm_textAndCommentOfRule(ruleID);
  if (p == null) null;
  gazelle_addRuleWithComment(newText, p.b);
  ret dm_gazelle_addRuleWithComment_msg!;
}