Detection of upgrading in events

[Dersei]

Hi, I'm trying to implement upgrading and encountered an unusual issue with IsUpgradingInstalledVersion() within the UIInitialized and UILoaded events.

The problem lies in the fact that this method relies on three conditions including session.Property("FOUNDPREVIOUSVERSION").IsNotEmpty(), however at this point, the property hasn't been set yet.

1. LookupInstalledVersion() returns correct value of the installed version of the app though, so my question is: can this be used reliably within these events to detect upgrading?

2. Additionally, could the logic in IsUpgradingInstalledVersion() be updated to something more like this?:

session.IsInstalling() && !session.IsModifying() &&
               (session.Property("FOUNDPREVIOUSVERSION").IsNotEmpty()  || session.LookupInstalledVersion() != null)

As far as I can tell that should work the same way for the current use case but also work correctly inside these two events.

Anyway, thanks for amazing work!

Edit: As far as I can tell the same situation is true when using this property inside view model of WPF dialog.

[oleg-shilo]

You are right, these two events are special as they are executed at the very early stage of the MSI session.

Your proposal makes sense. I will implement it in the very next release.

Thank you for your contribution.