CSS generated content without space goes missing (Safari) #403

<polymer-element name="ui-icon" noscript>
  <template>
    <style>
      :host {
        display: block;
      }
      #one::before {
        content: "hi there";
      }
      #two::before {
        content: "hithere"; / * doesn't work no space */
      }
      #three::before {
        content: " hi there"; / * works */
      }
      #four::before {
        content: "hithere "; / * works */
      }
    </style>
    <div id="one">1</div>
    <div id="two">2</div>
    <div id="three">3</div>
    <div id="four">4</div>
  </template>
</polymer-element>