.NET Host MSI's upgrade during one major release and across several releases

[NikolaMilosavljevic]

.NET Host MSI installs components shared across releases, to a shared location, using static component codes.

This issue tracks defining valid experiences and desired outcomes and will serve as a source for new issues, fixes or features in the product.

While components are shared across releases, and properly ref-counted, MSIs in different .NET (Core) releases are different (distinct) and do not upgrade one another.

This design is blocking some scenarios, i.e. renaming any of the files carried by these components, see #2243. Renaming the file without doing more changes in .NET Core 3.1 and .NET 5.0 would result in 2 files installed next to each other, old (ThirdPartNotices.txt) and new (THIRD-PARTY-NOTICES.txt). Further analysis of 3.1 and 5.0 installers is required to solve that problem.

Some of the open questions:

1. Should .NET Host MSI have the static upgrade code?
2. Should new versions of .NET Host MSI upgrade products shipped with previous releases?

[NikolaMilosavljevic]

@dleeapho @dagood @leecow @MichaelSimons @nakarnam

[leecow]

Make sure to include the Host folks (Vitek and others) in any design discussions.

[NikolaMilosavljevic]

[Triage] we should investigate using static upgrade code.

[NikolaMilosavljevic]

[Triage] @ashnaga can we add this to any current epics for Windows installation improvements?