[release/6.0] fix issue where HTTP2 connection could be scavenged but not disposed

[github-actions]

Backport of #62225 to release/6.0

/cc @stephentoub @geoffkizer

Customer Impact

When scavenging connections, if we end up scavenging at least one HTTP/1.1 connection and at least one HTTP2 connection for the same connection pool (i.e. origin server), the first HTTP2 connection will be removed from the connection list but not disposed, leading to a connection leak.

Having both HTTP/1.1 and HTTP2 connections to the same server is not common, but if this happens the impact is pretty bad.

This is a regression in 6.0.

Testing

Customer provided with private binaries. They confirmed the change works and fixes the issue.

Risk

Very low -- trivial fix.

[ghost]

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Issue Details

---

Backport of #62225 to release/6.0

/cc @stephentoub @geoffkizer

Customer Impact

Testing

Risk

Author:	github-actions[bot]
Assignees:	-
Labels:	area-System.Net.Http
Milestone:	-

[danmoseley]

@karelz can you please handle tactics mail for this as Im going to be out.

[safern]

I'll merge whenever this is approved by tactics.

[safern]

/azp run runtime

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[safern]

/azp run runtime-libraries enterprise-linux

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[karelz]

CI failures:

• runtime (Libraries Build windows allConfigurations x64 Debug) - 2x - same as 'The "Microsoft.DotNet.Compatibility.ValidatePackage" task failed unexpectedly' in libs legs #59908?

.packages\microsoft.dotnet.compatibility\1.0.0-rc.2.21511.46\build\Microsoft.NET.Compatibility.Common.targets(32,5): error MSB4018: (NETCORE_ENGINEERING_TELEMETRY=Build) The "Microsoft.DotNet.Compatibility.ValidatePackage" task failed unexpectedly.
System.TypeLoadException: Method 'CompareSourceLocations' in type 'Microsoft.CodeAnalysis.CSharp.CSharpCompilation' from assembly 'Microsoft.CodeAnalysis.CSharp, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' does not have an implementation.
   at Microsoft.DotNet.ApiCompatibility.AssemblySymbolLoader..ctor(Boolean resolveAssemblyReferences)
   at Microsoft.DotNet.PackageValidation.ApiCompatRunner.GetAssemblySymbolFromStream(Stream assemblyStream, MetadataInformation assemblyInformation, Boolean& resolvedReferences) in /_/src/Compatibility/Microsoft.DotNet.PackageValidation/ApiCompatRunner.cs:line 113
   at Microsoft.DotNet.PackageValidation.ApiCompatRunner.RunApiCompat() in /_/src/Compatibility/Microsoft.DotNet.PackageValidation/ApiCompatRunner.cs:line 50
   at Microsoft.DotNet.PackageValidation.CompatibleTfmValidator.Validate(Package package) in /_/src/Compatibility/Microsoft.DotNet.PackageValidation/CompatibleTFMValidator.cs:line 122
   at Microsoft.DotNet.Compatibility.ValidatePackage.ExecuteCore() in /_/src/Compatibility/Microsoft.DotNet.Compatibility/ValidatePackage.cs:line 91
   at Microsoft.NET.Build.Tasks.TaskBase.Execute() in /_/src/Tasks/Common/TaskBase.cs:line 38
   at Microsoft.DotNet.Compatibility.ValidatePackage.Execute() in /_/src/Compatibility/Microsoft.DotNet.Compatibility/ValidatePackage.cs:line 49
   at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute()
   at Microsoft.Build.BackEnd.TaskBuilder.ExecuteInstantiatedTask(ITaskExecutionHost taskExecutionHost, TaskLoggingContext taskLoggingContext, TaskHost taskHost, ItemBucket bucket, TaskExecutionMode howToExecuteTask)

• 3 unrelated Sockets test failures on Win11 - results - tracked by System.Net.Sockets.Tests.SendPacketsAsync.SendPacketsElement_FileZeroCount_Success sometimes fails #60017

    System.Net.Sockets.Tests.SendPacketsAsync.SendPacketsElement_FileStreamMultiPartMixed_MultipleFileStreams_Success [FAIL]
      Timed out
      Expected: True
      Actual:   False
      Stack Trace:
        /_/src/libraries/System.Net.Sockets/tests/FunctionalTests/SendPacketsAsync.cs(693,0): at System.Net.Sockets.Tests.SendPacketsAsync.SendPackets(SendPacketsElement[] elements, SocketError expectedResult, Int32 bytesExpected, Byte[] contentExpected)
        /_/src/libraries/System.Net.Sockets/tests/FunctionalTests/SendPacketsAsync.cs(598,0): at System.Net.Sockets.Tests.SendPacketsAsync.SendPacketsElement_FileStreamMultiPartMixed_MultipleFileStreams_Success()
    System.Net.Sockets.Tests.SendPacketsAsync.SendPacketsElement_FileStreamLargeOffset_Throws [FAIL]
      Timed out
      Expected: True
      Actual:   False
      Stack Trace:
        /_/src/libraries/System.Net.Sockets/tests/FunctionalTests/SendPacketsAsync.cs(693,0): at System.Net.Sockets.Tests.SendPacketsAsync.SendPackets(SendPacketsElement[] elements, SocketError expectedResult, Int32 bytesExpected, Byte[] contentExpected)
        /_/src/libraries/System.Net.Sockets/tests/FunctionalTests/SendPacketsAsync.cs(670,0): at System.Net.Sockets.Tests.SendPacketsAsync.SendPackets(SendPacketsElement element, SocketError expectedResult, Int32 bytesExpected)
        /_/src/libraries/System.Net.Sockets/tests/FunctionalTests/SendPacketsAsync.cs(535,0): at System.Net.Sockets.Tests.SendPacketsAsync.SendPacketsElement_FileStreamLargeOffset_Throws()
    System.Net.Sockets.Tests.SendPacketsAsync.SendPacketsElement_FileStreamWithOptions_Success [FAIL]
      Timed out
      Expected: True
      Actual:   False
      Stack Trace:
        /_/src/libraries/System.Net.Sockets/tests/FunctionalTests/SendPacketsAsync.cs(693,0): at System.Net.Sockets.Tests.SendPacketsAsync.SendPackets(SendPacketsElement[] elements, SocketError expectedResult, Int32 bytesExpected, Byte[] contentExpected)
        /_/src/libraries/System.Net.Sockets/tests/FunctionalTests/SendPacketsAsync.cs(665,0): at System.Net.Sockets.Tests.SendPacketsAsync.SendPackets(SendPacketsElement element, Int32 bytesExpected, Byte[] contentExpected)
        /_/src/libraries/System.Net.Sockets/tests/FunctionalTests/SendPacketsAsync.cs(555,0): at System.Net.Sockets.Tests.SendPacketsAsync.SendPacketsElement_FileStreamWithOptions_Success()