only decode the url when the content of the link is a string

browser/components/MarkdownPreview.js

@@ -185,12 +185,14 @@ export default class MarkdownPreview extends React.Component {
   }
 
   fixDecodedURI (node) {
+    if (node && node.children.length === 1 && typeof node.children[0] === 'string') {
       const { innerText, href } = node
 
       node.innerText = mdurl.decode(href) === innerText
         ? href
         : innerText
     }
+  }
 
   componentDidMount () {
     this.refs.root.setAttribute('sandbox', 'allow-scripts')