Bug #16722 Fulltext: implicit limit for query word number (depends on length of the query)

Description:
This bug affects custom fulltext parsers only, built-in parser works just fine.

The problem is that MySQL has implicit limit for query word number which depends on length of the query:

limit= 1 + query_length / 2;

E.g.: 'AAAA' query length is 4, the limit is 3 words per this query, but if the parser expands query to 4 words ('test1', 'test2', 'test3', 'test4') it results in unexpected behavior. Note that query 'AAAAAA' works just fine.

How to repeat:
N/A

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/internals/33384

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/1668

Fixed in 5.1.6.
Removed implicit limit for query word number.

Documented in 5.1.6 changelog:

   <listitem>
        <para>
          Word limit removed from FULLTEXT to improve compatibility with
          custom parsers. (Bug #16722)
        </para>
      </listitem>