This patch adds code and a test when SQLite generates an 'unknown'
op for a table join in the BEST_INDEX() callback. The Perl code crashed
when such an op was generated for a JOIN criterion by the SQLite engine.
The SQLite engine creates an 'unknown' op on the following SQL
for example:
select r.nodepath
from temp.scan_results r
left join temp.scan_results m
on r.nodepath = m.nodepath+1
where m.nodepath is null
The important part is that the right side of the left join must be
checked for IS NULL.
- added support for undef (NULLs) in comparisons
- new test file t/virtual_table/rt_99748.t for testing nulls and comparing vtable with a regular table
- tests that no security holes can be inserted in compiled regexes
- ROWIDs start at 1, not at 0
- replaced qr{..} by m{..}
