Steps to replicate the issue (include links if applicable):
What happens?:
What should have happened instead?:
Note
Issue raised on https://www.mediawiki.org/w/index.php?title=Topic:Xdix8k106l2jq38l
As far as I can tell, this stems from a difference introduced by VE. The content coming from Parsoid reads like this:
<<body id="mwAA" lang="fr" class="mw-content-ltr sitedir-ltr ltr mw-body-content parsoid-body mediawiki mw-parser-output" dir="ltr" data-parsoid='{"dsr":[0,14,0,0]}'><p id="mwAg" data-parsoid='{"dsr":[0,14,0,0]}'><a rel="mw:MediaLink" href="./Special:FilePath/Plop" resource="./Média:Plop" title="Plop" typeof="mw:Error" data-mw='{"errors":[{"key":"apierror-filedoesnotexist","message":"This image does not exist."}]}' id="mwAw" data-parsoid='{"stx":"simple","a":{"resource":"./Média:Plop"},"sa":{"resource":"Media:Plop"},"dsr":[0,14,2,2]}'>Media:Plop</a></p></body>The content before save in VE reads like this:
<body id="mwAA" lang="fr" class="mw-content-ltr sitedir-ltr ltr mw-body-content parsoid-body mediawiki mw-parser-output" dir="ltr" data-parsoid='{"dsr":[0,14,0,0]}'><p id="mwAg" data-parsoid='{"dsr":[0,14,0,0]}'><a href="./Média:Plop" rel="mw:WikiLink" resource="./Média:Plop" title="Plop" typeof="mw:Error" id="mwAw" data-parsoid='{"stx":"simple","a":{"resource":"./Média:Plop"},"sa":{"resource":"Media:Plop"},"dsr":[0,14,2,2]}' data-mw='{"errors":[{"key":"apierror-filedoesnotexist","message":"This image does not exist."}]}'>Media:Plop</a></p></body>Note in particular the transformation from "MediaLink" to "WikiLink", which in turns makes DOMDiff detect a wrapper change, which regenerates the link - with the "local" namespace prefix. Not sure whose fix that one is :)
It might be worth checking if Parsoid will not dirty if you run selser with VE's HTML as your new.html but where you update the mw:WikiLink back to mw:MediaLink. If that doesn't get dirtied, it would indicate that a fix in VE would fix the problem. If not, we probably have things to find in both Parsoid and VE.
Indeed, updating back to mw:MediaLink seems to be enough for Parsoid to not have a dirty-diff there. It still displays a "modified-wrapper", but it round-trips without the accent as expected.