don't send server_name when literal IP

[wfurt]

fixes#81590

I originally tried to use IPAddress.TryParse() But it allocates and drags in many dependencies.
Windows SChannel already do this so we could possibly skip it. But the check should be reasonably cheap so I left it in for all platforms.

HttpClient always sets it for IP addresses. I was hoping we could check Uri.HostNameType but by the time it hits the SslStream it is already passed as string and it is part of the connection pool processing. So left the fix-up only in SslStream.

We should probably do the same for Quic when we do #80508. (not sure if Quic allows to connect to empty string)

cc: @simonrozsival@nibanks

[ghost]

Tagging subscribers to this area: @dotnet/ncl, @vcsjones
See info in area-owners.md if you want to be subscribed.

Issue Details

---

fixes #81590

I originally tried to use IPAddress.TryParse() But it allocates and drags in many dependencies.
Windows SChannel already do this so we could possibly skip it. But the check should be reasonably cheap so I left it in for all platforms.

HttpClient always sets it for IP addresses. I was hoping we could check Uri.HostNameType but by the time it hits the SslStream it is already passed as string and it is part of the connection pool processing. So left the fix-up only in SslStream.

We should probably do the same for Quic when we do #80508. (not sure if Quic allows to connect to empty string)

cc: @simonrozsival@nibanks

Author:	wfurt
Assignees:	wfurt
Labels:	area-System.Net.Security
Milestone:	8.0.0

[rzikm]

LGTM!

[simonrozsival]

LGTM! This partially fixes #79143 and will unblock System.Net.Http.Functional.Tests.SocketsHttpHandler_HttpClientHandlerTest.GetAsync_IPv6LinkLocalAddressUri_Success on Android 👍