[8.0] Guard against empty Accept address

[wfurt]

Backports #108616

Fixes #108026 and #102663

Customer Impact

• Customer reported
• Found internally

There is problem in 8.0+ when Socket.Accept can fail and throw exception on background thread on macOS, which leads to application termination. This was already reported by 2 customers who upgraded to 8.0 from previous LTS 6.0 - see #108026 and #102663.

Regression

• Yes - from 7.0 to 8.0
• No

Prior 8.0 we used internal duplicate of class SocketAddress that was apparently more forgiving in certain corner cases. We switch in 8.0 to ussage of public API that is more strict.

Testing

The fix was merged to main and verified by customer. Also 8.0 binaries were tested in their lab. See #108334 (comment) for details.

Risk

Low. The fix basically checks for error condition to avoid throwing. It seems like the condition is coming from Darwin kernel where sometime accept operation fails to provide remote address.

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[wfurt]

/backport to main

[github-actions]

Started backporting to main: https://github.com/dotnet/runtime/actions/runs/11221178118

[carlossanlop]

Friendly reminder that today 10/14 is Code Complete for the November Release. If this fix is intended to be included in that release, please make sure it's merged before 4pm PT. Otherwise, it will have to wait until next month.

[pepone]

@wfurt I finally come around to test this. We have two tests in https://github.com/zeroc-ice/ice that where hitting this issue pretty often when run with IPv6 and both are working fine with this branch.

We are also hitting this issue with GitHub macOS runners, for a different project

https://github.com/icerpc/icerpc-csharp/actions/runs/11842033975/job/32999706878

Pretty annoying because it brings the test host process down:

The active test run was aborted. Reason: Test host process crashed : Unhandled exception. System.ArgumentException: The supplied System.Net.SocketAddress is an invalid size for the System.Net.IPEndPoint end point. (Parameter 'socketAddress')
   at System.Net.IPEndPoint.Create(SocketAddress socketAddress)

[wfurt]

it seems like we have enough evidence to proceed with servicing request @karelz

[karelz]

Regression in 8.0 (LTS) against 7.0. Impact on customers - crash, without a workaround.
We should fix it.