[OAK-9252] Query: multi-valued property condition can fail with "Type must be an array type"

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.36.0
• Assignee: Thomas Mueller
• Reporter: Thomas Mueller
• Created: 06/Oct/20 15:20
• Updated: 17/Nov/20 10:17
• Resolved: 15/Oct/20 08:28

Description

A condition of the form "property = 'literal'" can fail with the error message "Type must be an array type" if:

• the property is multi-value and has no entries (count 0)
• the property type is not String (e.g. Name)

Example query:

select * from [nt:base]
where isdescendantnode('/etc') 
and [jcr:mixinTypes] = 'mix:referenceable' 

This can fail if there is no index for this (e.g. by disabling the nodetype index), and if there is a node with an empty mixin type. Test case (org.apache.jackrabbit.oak.jcr.query.QueryTest):

    @Test
    public void emptyMixin() throws RepositoryException {
        Session session = createAdminSession();
        Node p = session.getRootNode().addNode("etc");
        Node r = p.addNode("r", "nt:unstructured");
        r.addMixin("mix:referenceable");
        session.save();
        r.removeMixin("mix:referenceable");
        session.save();
        assertTrue(r.hasProperty("jcr:mixinTypes"));
        Property mix = r.getProperty("jcr:mixinTypes");
        assertTrue(mix.isMultiple());
        assertEquals(0, mix.getValues().length);
        session.save();
        Query q = session.getWorkspace().getQueryManager().createQuery(
                "select * from [nt:base] where isdescendantnode('/etc') " +
                "and [jcr:mixinTypes] = 'mix:referenceable' " +
                "option(index name [x])", Query.JCR_SQL2);
        QueryResult qr = q.execute();
        NodeIterator ni = qr.getNodes();
        assertFalse(ni.hasNext());
        session.logout();
    }