Consider the following statements:

<pre>
CREATE TABLE t0(c0 COLLATE RTRIM, c1 BLOB UNIQUE, PRIMARY KEY (c0, c1)) WITHOUT ROWID;
INSERT INTO t0 VALUES (123, 3), (' ', 1), ('	', 2), ('', 4);
SELECT * FROM t0 WHERE c1 = 1; -- expected: ' ', 1, actual: no row is fetched
</pre>

I would expect a row to be fetched, which is not the case. Note that the whitespace seems to be significant: the first one is a space, the second one a tab, and the third one an empty string.