Not sure if this is a problem with the wiki or MCS itself...
When using this query: https://bm.wikipedia.org/api/rest_v1/page/mobile-sections/Seshel
The response HTML includes a reference to this image: //upload.wikimedia.org/wikipedia/commons/thumb/a/a1/Coat_of_arms_of_the_Seychelles.svg/125px-Coat_of_arms_of_the_Seychelles.svg.png
This leads to a 404, and causes MWOffliner to have missing images in scrapes:
https://github.com/openzim/mwoffliner/issues/616
Bumping that one upstream to Parsoid.
It works on https://bm.wikipedia.org/wiki/Seshel but the Parsoid output (https://bm.wikipedia.org/api/rest_v1/page/html/Seshel) uses a different file name for the svg image.
The Parsoid version has an extra "the" in the file name. Not sure where it comes from. It could be related to https://bm.wikipedia.org/api/rest_v1/page/html/Fichier:Coat_of_Arms_of_the_Republic_of_Seychelles.svg redirecting to https://commons.wikimedia.org/api/rest_v1/page/html/File%3ACoat_of_arms_of_Seychelles.svg.
Hmm, so the file was renamed recently on 2018-02-10,
https://commons.wikimedia.org/w/index.php?title=File%3ACoat_of_arms_of_Seychelles.svg&type=revision&diff=338463956&oldid=338257332
Asking for a purge (?action=purge) rerendered the page correctly,
https://bm.wikipedia.org/api/rest_v1/page/html/Seshel
It looks like, because Parsoid links directly to thumbnailed images, we need changeprop to tell us to rerender all the pages linking to the file. Hopefully renames are rare.
@ssastry I don't really understand why this ticket is closed. There is no agreement that this is a bug?
This is a serious matter for the offline versions of our wikis, the consequences of this are broken HTML articles (= with broken images). This is not rare, I have many examples only with Wikivoyage in English. Just the renaming of "File:BC-3_(Crowsnest).svg" breaks itself around 20 articles.
And not only it generates broken HTML, but also this makes detecting our own scraping/rendering problems on MWoffliner side more complicated. Our own quality processes are challenged.
I'm also sure this has also an impact on other tools based on Parsoid output. Considering the level of impact, I would like to see this ticket re-opened, properly assigned and triaged adequately.
@Kelson. Sorry, I didn't imply this wasn't a bug. I did say this is a ChangePropagation issue and tagged @Pchelolo and @mobrovac and asked them to reopen / file a diferent ticket. But, yes a better solution would have been to untag Parsoid and MCS and tag ChangePropagation, which I am going to do now. Thanks for following up and apologies for my confusing triage.
@bearND I've left behind the RI-Team-Backog tag and removed the MCS tag. But, feel free to update your team / project tags as appropriate.
Still a new case here: https://es.wikipedia.org/api/rest_v1/page/html/Anexo:Baloncesto_en_los_Juegos_Mediterr%C3%A1neos_de_1951, 15 days after image renaming on Commons (https://commons.wikimedia.org/w/index.php?title=Special:Log&page=File%3AFlag+of+Egypt+%281922%E2%80%931958%29.svg), the rendered HTML still points to a the wrong/old/404 thumbnail.
This impacts the whole Parsoid, not only mobile.
T284570 is a similar case where a file was moved from enwiki to commons and changeprop did not request to rerender the pages including it.
A user newly reported to us about missing images in the REST API HTML output because of this bug:
See https://github.com/openzim/mwoffliner/issues/1530 for more details.