I've copied one line of my global contributions at https://en.wikipedia.org/wiki/User:Jonteemil/sandbox5. The link to the section which is represented by → should direct you to https://fr.wikipedia.org/wiki/Wikipédia:Demande_de_renommage#Correcting_file_extensions_that_currently_doesn't_match_MIME but currently directs you to https://fr.wikipedia.org/w/index.php?title=Wikip%C3%A9dia:Demande_de_renommage#Correcting_file_extensions_that_currently_doesn.26.23039.3Bt_match_MIME.
The apostrophy is replaced by .26.23039.3B for some reason. I would assume it is the same with other types of non-letter symbols. Anyway, you don't get sent to the section, which is a problem.