[wix-users] Update version number not via MSI / uninstall same-upgrade-code MSI when uninstalling

[Alon Dean]

Hi,
I know the title may be confusing, so let me explain what I'm trying to
accomplish:
(At my work) I created a hybrid MSI - It does *some* of the installation
operations, and the rest of the operations are being performed by custom
actions.
This was done as part of my task of embedding a software-update mechanism
to our application (using squirrel.windows)

The problem is that when an update occurs, it doesn't involve the MSI in
any way - so the client gets a new version (not via MSI), and the MSI
doesn't reflect that in the version number at the control panel (from the
registry)
So I need to find a solution for that...

I've seen this SO question and the answers to it:
https://stackoverflow.com/questions/28195435/update-installed-msi-version-from-exe

I don't want to hack the registry for that, what I would like to do is:

Create another small MSI, with a version number that will be changed
according to the update's version number.
Once an update is installed, this MSI will also be installed, adding an
entry to the control panel with the *correct* version number.
Then, I'll need to hide the 'main' MSI from the control panel.

My problem is: how to make the new, small MSI uninstall the 'main' MSI once
uninstalling?
I know this is related to the upgrade code but not sure how to accomplish
it.

And overall, would you say, given the assumption that my updates' framework
doesn't involve the MSI, that I'm taking the right approach?

Any help would be much appreciated
Thanks!
Alon