We now store a sitelink as a pair of site id and title, which is a bit fragile. For example it will break on ordinary page moves. An alternate approach is to store the article id and first try to use this if it is available, and then use the title as a second approach. The titles could be lazy-updated if thy get out of sync.
Version: unspecified
Severity: normal
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=36729