Set-count is broken

[michael-e]

Here is some example XML I get using the set-count action:

<events>
    <storage-action type="set-count" result="success">
        <request-values>
            <group id="basket">
                <item id="article1" difference="+3"/>
            </group>
        </request-values>
    </storage-action>
</events>
<m-storage>
    <group id="basket">
        <item id="article1" count="3"/>
    </group>
</m-storage>

Looks good for the first submit. :-)

The problem is: It's exactly the same for subsequent submits. It doesn't increase the count at all.

[michael-e]

I verified that the problem occurs for count-positive as well as count.