Query with an AND predicate, NOT and comparison yields an incorrect result

[mrigger]

Consider the following statements:

CREATE TABLE t0(c0 INT);
CREATE TABLE t1(c0 INT);
INSERT INTO t0(c0) VALUES (0);
INSERT INTO t1(c0) VALUES (0);
SELECT * FROM t1, t0 WHERE NOT ((t1.c0 AND t0.c0) < 0); -- expected: {0|0}, actual: {}

Unexpectedly, the query does not fetch a row. The predicate should evaluate to TRUE for the rows in t0, and t1. The negated predicate works as expected and does not fetch any rows:

SELECT * FROM t1, t0 WHERE ((t1.c0 AND t0.c0) < 0); -- {}

I found htis based on the latest commit to master (9795d18).

[Mytherin]

Fixed this in d88e21d. The issue was that in the planning of a join with an expression in the form of NOT(comparison) we tried to invert the underlying comparison, e.g. NOT(x < 0) is equivalent to x >= 0. The problem is that we did this, then tried to split the comparison into a left and right side, and if this did not succeed we did not properly revert the comparison.

In this query what it would mean is the following:

-- original expression
NOT((t1.c0 AND t0.c0) < 0)
-- transform into:
(t1.c0 AND t0.c0) >= 0
-- cannot divide into left/right side! treat as arbitrary expression
NOT((t1.c0 AND t0.c0) >= 0) -- <= BUG!

I now moved this inversion of the NOT to the parser, so the parser would already invert NOT(x <y) to x>=y. This also makes the code cleaner in general :)