Setting priority to low as a workaround exists.
Example might be welcome so somebody could theoretically investigate.

So:

• I have finaly updated the reference document
• zimlib does not need to be changed.
• Kiwix 0.9 is able to deal with relative urls
• ZIM files produced by Kiwix use now relative URls

I close this ticket.

Sorry, this is about the collection extension... and not the openzim project. This extension still need to be fixed.

The new mw-ocg-zimwriter will get this right, presumably. ;)

I think this bug can be closed.

For the record, this 10 years old ticket, has been a real bug. It happened at the time we discovered we had to have relative links in HTML inside the ZIM to allow a certain flexibility in the way how the ZIM could be "mounted". This was and is particulary true with kiwix-serve. I believe this bug to have been open at a time the libzim tracker was in Phabricator, so the bug was at the right place. Unfortunately, the tagging seemed wrong and this ticket has - looks like - not been closed at the time the libzim bug tracker has been moved to openZIM organisation (which is already a long time ago). Obviously, since years, ZIM should provide (and provide) HTML content with relative URLs.