when validating vcol's (default, check, etc) in ALTER TABLE
vcol_info->flags are modified in place. This means that if ALTER TABLE
fails for any reason we need to restore them to their original values.
(mroonga was freeing the memory on ::reset() but not on ::close())
This reverts commit 5a9e2b77d4 in 10.5,
so it produces an error on "bad" generated columns.
Note, 10.2, 10.3, 10.4 produce only warnings, for backward compatibility.
This patch allows the server to open old tables that have
"bad" generated columns (i.e. indexed virtual generated columns,
persistent generated columns) that depend on sql_mode,
for general things like SELECT, INSERT, DROP, etc.
Warning are issued in such cases.
Only these commands are now disallowed and return an error:
- CREATE TABLE introducing a "bad" generated column
- ALTER TABLE introducing a "bad" generated column
- CREATE INDEX introdicing a "bad" generated column
(i.e. adding an index on a virtual generated column
that depends on sql_mode).
Note, these commands are allowed:
- ALTER TABLE removing a "bad" generate column
- ALTER TABLE removing an index from a "bad" virtual generated column
- DROP INDEX removing an index from a "bad" virtual generated column
but only if the table does not have any "bad" columns as a result.