Fix the sqlite3_db_readonly() API so that it reports true if the database
is readonly because the file format write version (byte 18 of the header)
is too large.
Do not burn memory remembering CHECK constraints in a read-only database.
Add a test for the EQP output of a skip-scan query that uses the PK index of a WITHOUT ROWID table.
Make sure sufficient VDBE registers are allocated for an INSERT...SELECT
when there is an idlist on the insert table that includes an explicit
rowid.  Ticket [9654505cfda93610585fde5a9bbf2e730c8a8d5]
In the command-line shell, if three or more interrupt signals (control-c)
are received in a row without a response from sqlite3_interrupt() then
call exit(1) immediately.  This allows control-C to interrupt the shell
even if it is stuck in a computation or loop that does not involve the
VDBE.
Changes to the output of EXPLAIN QUERY PLAN to make it clearer when a query uses the PRIMARY KEY index of a WITHOUT ROWID table.
Remove references in comments to VDBE opcodes that no longer exist.  This
is a documentation change only; no changes to code.
Fix a problem in FTS4 where columns with names that are prefixes of any notindexed column were also being (incorrectly) marked as not indexed. For example in "CREATE ... t1(abc, bc, abcd, notindexed=abcd)", both abc and abcd were being treated as notindexed.
Fix a problem in the shell when importing CSV files. If the leftmost field of the first row in the CSV file was both zero bytes in size and unquoted, no data was imported.
Merge recent trunk changes into the threads branch.