SQLite

If a database schema uses an application-defined collating sequence, and an instance of SQLite is run on that database that does not have the necessary collating sequence defined, then the "REINDEX" and "PRAGMA integrity_check" commands run without generating an error and substitute the built-in BINARY collating sequence in place of the application-defined collating sequence. Running the REINDEX command this way corrupts the index (though the corruption can be reversed by rerunning REINDEX in a new database connection where the application-defined collating sequence has been defined). Running PRAGMA integrity_check this way results in spurious errors.

This problem appears to have been introduced by check-in [8542e6180d4321d] and first appeared in release 3.7.15.