Commit f691f0c2 authored by Committed by Marge BotBrowse files
PmCheck: Look up parent data family TyCon when populating `PossibleMatches`
The vanilla COMPLETE set is attached to the representation TyCon of a data family instance, whereas the user-defined COMPLETE sets are attached to the parent data family TyCon itself. Previously, we weren't trying particularly hard to get back to the representation TyCon to the parent data family TyCon, resulting in bugs like #17207. Now we should do much better. Fixes the original issue in #17207, but I found another related bug that isn't so easy to fix.