I found the issue with copyfields as you mentioned Robert. foo is omitNorms=false, and bar is omitNorms=true. I have a copyfield foo->bar and I add a document like:
This case is fixed by the patch. Testing it, i found a similar situation where a field1 is a poly type with omitNorms=false, and the subtype if it has omitNorms=true. In this case, it fails even without a copyfield just by adding a document like:
I don't know if it makes sense to have a poly field where the subtype have a different value in the "omitNorms" attribute, probably this should fail even before the document is added.