[wix-users] FindRelatedProducts and install context

[Alan Sinclair]

I'm making a dual-scope MSI which will install per-user or per-machine
depending on the user's choice in the InstallScope dialog.

The MSI uses FindRelatedProducts to discover if it's an upgrade. But there
seems to be a snag: FindRelatedProducts seems only to look in the scope
that's active in when the MSI starts .. in this case that's per-user scope,
because FindRelatedProducts runs before the UI and the MSI has initial
values of ALLUSERS=2 and MSIINSTALLPERUSER=1.

So if the user installed per-machine that's not going to be found
by FindRelatedProducts.

What am I missing or misunderstanding?  Can a dual-scope package which is
installed per-machine be upgraded somehow?

thanks
Alan