Fix 500 error for erroneous content in markdown footnotes
What does this MR do and why?
Contributes to #452051 (closed)
Problem
User can use a custom footnote syntax. The code cannot correctly handle the case when HTML links don't have an "id".
Solution
Handle the error by skipping malformed footnote links.
How to reproduce
- Update the README file of the project with a following content
<p>first<sup><a href="#fn-1" id="fnref-1" data-footnote-ref>1</a></sup> and second<sup><a href="#fn-second" id="fnref-second" data-footnote-ref>2</a></sup> and third<sup><a href="#fn-_%F0%9F%98%84_" id="fnref-_%F0%9F%98%84_" data-footnote-ref>3</a></sup></p>
<p>missing id<sup><a href="#fn-10" data-footnote-ref>1</a></sup></p>
<section data-footnotes>
<ol>
<li id="fn-1">
<p>one <a href="#fnref-1" data-footnote-backref data-footnote-backref-idx="1" aria-label="Back to reference 1">↩</a></p>
</li>
<li id="fn-second">
<p>two <a href="#fnref-second" data-footnote-backref data-footnote-backref-idx="2" aria-label="Back to reference 2">↩</a></p>
</li>\n<li id="fn-_%F0%9F%98%84_">
<p>three <a href="#fnref-_%F0%9F%98%84_" data-footnote-backref data-footnote-backref-idx="3" aria-label="Back to reference 3">↩</a></p>
</li>
</ol>
- It should be rendered without any errors (before it would return a 500 error)
Edited by Vasilii Iakliushin