PackagePathResolver.GetPackageDirectoryName should be virtual

[albahari]

I am the author of LINQPad - a popular code scratchpad which has integrated support for NuGet. I'm in the process of upgrading LINQPad's NuGet support from NuGet 3.x to NuGet 4.x.

I've run into a blocking issue: the methods in PackagePathResolver used to be virtual in NuGet 3.x and they are non-virtual in NuGet 4.x, so my subclassed PackagePathResolver no longer compiles. I need PackagePathResolver.GetPackageDirectoryName to be virtual so that I can override this method to encode the name when it exceeds a certain length. This is an essential workaround to avoid "path too long" errors. These errors occur more frequently in LINQPad than VS, because a long root directory is required (this is a a consequence of LINQPad having a snippet-based architecture rather than a project-based architecture).

Let me know if I should submit a pull request. It's simply a matter of inserting "virtual" before that method declaration - and LINQPad will then enjoy NuGet 4.x integration :)

[rrelyea]

@emgarten - can you please advise or farm out to a more appropriate team member here.
I think we'd consider a PR for this (or alternate solutions), once we verify that aren't complications, for 4.4.

[emgarten]

There are two path resolvers, one for v2 and one for v3 folder formats.

https://github.com/NuGet/NuGet.Client/blob/dev/src/NuGet.Core/NuGet.Packaging/PackagePathResolver.cs

https://github.com/NuGet/NuGet.Client/blob/dev/src/NuGet.Core/NuGet.Packaging/VersionFolderPathResolver.cs

I think they should both be made virtual as part of this.

[emgarten]

@albahari a PR for this would be great. Otherwise @rohit21agrawal would you take a look at this for 4.4?