Steps to replicate the issue (include links if applicable):
$ echo "[http://example.com foo'''] bar'''" | php maintenance/run parse <p><a rel="nofollow" class="external text" href="http://example.com">foo<b></b></a><b> bar</b> </p> $ echo "[http://example.com foo'''] bar" | php maintenance/run parse --parsoid <section data-mw-section-id="0" id="mwAQ"><p id="mwAg"><a rel="mw:ExtLink nofollow" href="http://example.com" class="external text" id="mwAw">foo<b id="mwBA"></b></a> bar</p>
For wikilinks, however:
$ echo "[[plop|aaa''']] aaa" | php ./maintenance/run parse.php <p><a href="/wiki/Plop" title="Plop">aaa<b></b></a> aaa $ echo "[[plop|aaa''']] aaa" | php ./maintenance/run parse.php --parsoid <section data-mw-section-id="0" id="mwAQ"><p id="mwAg"><a rel="mw:WikiLink" href="http://localhost/wiki/Plop" title="Plop" id="mwAw">aaa<b id="mwBA"></b></a> aaa</p>
What happens?:
Observe that the Legacy parser "bar" after the external link is bold, whereas it's not in Parsoid. This also means that a ''' formatting element after the link will have the opposite effect in both parsers.
This behaviour is also not consistent depending on the link type: for Wikilinks, the formatting element is stopped at the link boundary on both parsers.
What should have happened instead?:
Formatting elements in links should be consistent between the parsers and between external and wikilinks.
Note
Detected on visualdiff on https://ang.wiktionary.org/wiki/Br%C5%ABcendm%C5%8Dtung:%D7%9C%D7%A2%D7%A8%D7%99_%D7%A8%D7%99%D7%99%D7%A0%D7%94%D7%90%D7%A8%D7%98