The following code generates an assertion fault on the SELECT:

<blockquote><verbatim>
CREATE VIRTUAL TABLE x USING fts4(y,z);
INSERT INTO x VALUES('aaa bbb ccc ddd', 'bbb ddd aaa ccc');
SELECT * FROM x where y MATCH 'bbb NEAR/6 aaa';
</verbatim></blockquote>

This problem was introduced when the FTS4 prefix option was added with
check-in [b1f9c1e0ac51c] on 2011-04-14 for version 3.7.7.