Formula on Many-to-one pointing to a composite-keyed entity don't work

You can map the formula per each expected parts of the compisite-id.

<many-to-one name="Blah">
<formula>formula for the first element of the id</formula>
<formula>formula for the second element of the id</formula>
</many-to-one>

Sorry I use attributes normally.
above case SomeEntity is a table actually also it is an entity with composite ids.
The problem is Mapping validation process assumes if the many-to-one class has a composite id It must have two columns mapped. This check should be skipped if formula is used. I don't have test case right now but i will prepare one.

What you mean ?
where are you using that mapping line where is the mapping of "SomeEntity" ?
many-to-one has <formula> tag (not attribute) and you should use it in case of composite-id.
please attach a failing tests case.