Incorrect `padding` optimization (CSS variables problem)

[dizel3d]

.foobar {
  padding: var(--button-size-m-text-indentAll);
  padding-right: var(--button-size-m-icon-indentRight);
}

becomes

.foobar {
  padding: var(--button-size-m-text-indentAll) var(--button-size-m-icon-indentRight) var(--button-size-m-text-indentAll) 
  var(--button-size-m-text-indentAll);
}

It's incorrect for

--button-size-m-text-indentAll: 0 20px;
--button-size-m-icon-indentRight: 30px;

and suboptimal as well.