[Blazor] Workaround linker regression

[javiercn]

The linker seems to be incorrectly trimming the getters for one of our types. This PR includes a descriptor to ensure that the members of the exchange type are never serialized out and avoids using a serialization context as that breaks serialization for user provided data types.

Description

The linker is linking out the getters for one of our exchange types. This is the link output in 7.0

This is the link output in 6.0

Fixes #44973

Customer Impact

Breaks the ability to return to the original page after the user is redirected for authentication purposes as well as the ability to pass options to control the login process.

Workaround

Add this to your csproj

<ItemGroup>
  <TrimmerRootDescriptor Include="TrimmerRootDescriptor.xml" />
</ItemGroup>

And this is TrimmerRootDescriptor.xml:

<?xml version="1.0" encoding="UTF-8" ?>
<linker>
	<assembly fullname="Microsoft.Authentication.WebAssembly.Msal" preserve="all" />
	<assembly fullname="Microsoft.AspNetCore.Components.WebAssembly.Authentication" preserve="all" />
</linker>

Regression?

• Yes
• No

6.0

Risk

• High
• Medium
• Low

The fix uses a linker descriptor to explicitly prevent the members for that type from being trimmed away.

Verification

• Manual (required)
• Automated

Packaging changes reviewed?

• Yes
• No
• N/A

---

When servicing release/2.1

• Make necessary changes in eng/PatchConfig.props

[ghost]

Hi @javiercn. Please make sure you've updated the PR description to use the Shiproom Template. Also, make sure this PR is not marked as a draft and is ready-to-merge.

To learn more about how to prepare a servicing PR click here.

[javiercn]

The associated linker issue in the runtime is dotnet/linker#3110

[ghost]

Hi @javiercn. This PR was just approved to be included in the upcoming servicing release. Somebody from the @dotnet/aspnet-build team will get it merged when the branches are open. Until then, please make sure all the CI checks pass and the PR is reviewed.

[javiercn]

@dotnet/aspnet-build can I get some help here? Seems that one leg is failing to restore

[dougbu]

Should be fixed in the target branch. Right @wtgodbe❔

[dougbu]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 3 pipeline(s).

[javiercn]

@wtgodbe can you help so that this does not miss the train?

[wtgodbe]

##[error].dotnet/sdk/7.0.100/NuGet.targets(132,5): error MSB4018: (NETCORE_ENGINEERING_TELEMETRY=Restore) System.Threading.AbandonedMutexException: The wait completed due to an abandoned mutex. [/tmp/d043a9d2-cb34-439f-a93f-c7e1e4b6d110/restore.csproj]

@mmitche we're still seeing the AbandonedMutexException despite azp run-ing after the Arcade update: #44972

[wtgodbe]

I'm just force-merging this since the failure is unrelated

[wtgodbe]

If these failures are persistent we should un-revert the init nuget stuff from https://github.com/dotnet/aspnetcore/pull/44972/commits

[vanillajonathan]

Microsoft framework guidelines say you should use ICollection instead of IEnumerable.

[vanillajonathan]

Should use IDictionary instead of Dictionary.