The change to ALTER TABLE in [e1d8ec85546c] can cause indexes to go corrupt.
Sample code:

<blockquote><verbatim>
PRAGMA legacy_file_format=ON;
CREATE TABLE t1(a,b,c);
CREATE INDEX t1a ON t1(a DESC);
INSERT INTO t1 VALUES(1,2,3);
INSERT INTO t1 VALUES(2,3,4);
ALTER TABLE t1 ADD COLUMN d;
PRAGMA integrity_check;


If the schema version is initially less than 4, then the DESC keyword on
indexes is ignored.  If ALTER TABLE then changes the schema version to 4 from
a smaller value, then preexisting DESC indexes will be in the wrong order.

Corruption caused by this bug can be fixed by running the REINDEX command.