-- pg_tre 4.0.2 -> 4.1.0 upgrade.
--
-- No catalog changes: `diff sql/pg_tre--4.0.2.sql sql/pg_tre--4.1.0.sql`
-- differs only in the header comment's version string.
--
-- 4.1.0 refreshes the vendored sparsemap from v5.5.0 to v5.6.0, an upstream
-- security-hardening release, and adds the corruption detection that release
-- makes necessary.  The sparsemap wire format is unchanged (still version 2),
-- so there is **no on-disk format change and NO REINDEX required** -- every
-- existing posting page is read identically, verified cross-version across
-- ten map shapes.
--
-- One behaviour change worth knowing about: sparsemap now validates on open
-- and substitutes an empty map for bytes it rejects.  pg_tre cross-checks for
-- that and raises
--
--   ERROR:  pg_tre: corrupt inline sparsemap in posting for this trigram
--   HINT:   REINDEX the index to rebuild it.
--
-- rather than letting a damaged posting read as zero TIDs.  On a healthy
-- index this never fires: every map shape pg_tre writes passes the stricter
-- validator.  If you DO see it, the index has real damage -- REINDEX it, and
-- check the server log for a preceding checksum failure.
--
-- Note that with data_checksums on (the PG18 default) PostgreSQL reports
-- on-disk damage first, as "invalid page in block N".  These guards cover the
-- cases checksums do not: checksums disabled, or corruption arising in memory
-- after the page checksum was verified.