[wasm][net] System.Net.Mail should not throw PNSE for full assembly.

[kjpou1]

Add back certain functionality for System.Net.Mail.

Right now SmtpClient throws PNSE by providing a browser specific implementation.

Supported from the issue:

MailAddress passes:

            var emailAdddress = "foo@pt.lu";
            try
            {
                new MailAddress(emailAdddress);
            }
            catch (Exception exc)
            {
                Console.WriteLine(exc);
            }

Invalid email address parse:

System.FormatException: The specified string is not in the form required for an e-mail address.
   at System.Net.Mail.MailAddressParser.TryReadCfwsAndThrowIfIncomplete(String data, Int32 index, Int32& outIndex, Boolean throwExceptionIfFail)
   at System.Net.Mail.MailAddressParser.TryParseDomain(String data, Int32& index, String& domain, Boolean throwExceptionIfFail)
   at System.Net.Mail.MailAddressParser.TryParseAddress(String data, Boolean expectMultipleAddresses, Int32& index, ParseAddressInfo& parseAddressInfo, Boolean throwExceptionIfFail)
   at System.Net.Mail.MailAddressParser.TryParseAddress(String data, ParseAddressInfo& parsedAddress, Boolean throwExceptionIfFail)
   at System.Net.Mail.MailAddress.TryParse(String address, String displayName, Encoding displayNameEncoding, ValueTuple`4& parsedData, Boolean throwExceptionIfFail)
   at System.Net.Mail.MailAddress..ctor(String address, String displayName, Encoding displayNameEncoding)
   at System.Net.Mail.MailAddress..ctor(String address)
   at Sample.Test.Main(String[] args)

MailMessage with ContentDisposition passes:

    string file = "data.xls";
    // Create a message and set up the recipients.
    MailMessage message = new MailMessage(
        "jane@contoso.com",
        "ben@contoso.com",
        "Quarterly data report.",
        "See the attached spreadsheet.");

    // Create  the file attachment for this email message.
    Attachment data = new Attachment(file, MediaTypeNames.Application.Octet);
    // Add time stamp information for the file.
    ContentDisposition disposition = data.ContentDisposition;
    disposition.CreationDate = System.IO.File.GetCreationTime(file);
    disposition.ModificationDate = System.IO.File.GetLastWriteTime(file);
    disposition.ReadDate = System.IO.File.GetLastAccessTime(file);
    // Add the file attachment to this email message.
    message.Attachments.Add(data);

ContentDisposition constructor passes:

ContentDisposition c1 = new ContentDisposition();
Console.WriteLine(c1.ToString());

ContentDisposition c2 = new ContentDisposition("attachment");
Console.WriteLine(c2.ToString());

SmtpClient throws PNSE:

            try
            {
                new SmtpClient();
            }
            catch (Exception exc)
            {
                Console.WriteLine(exc);
            }

error:

System.PlatformNotSupportedException: Operation is not supported on this platform.
   at System.Net.Mail.SmtpClient.Initialize()
   at System.Net.Mail.SmtpClient..ctor()
   at Sample.Test.Main(String[] args)

CLI Tests ARE reactivated

Issue: #42576

[ghost]

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

[lewing]

What are you using as the bar to pull things back in?

[kjpou1]

Making sure the scenarios in the issue #42576 work and the tests pass.

[kjpou1]

Are we sure that the tests we have cover all the methods on all the classes that we are preserving?

The only thing we removed was the SmtpClient and left all the remaining Functional and Unit tests case coverage. That should catch any fallout.

[mdh1418]

I think we need to modify src/libraries/System.Net.Mail/src/Resources/Strings.resx since it was added when adding PNSE for System.Net.Mail in 80fe5bb.

[kjpou1]

I think we need to modify src/libraries/System.Net.Mail/src/Resources/Strings.resx since it was added when adding PNSE for System.Net.Mail in 80fe5bb.

Removed in recent round of commits

[mdh1418]

LGTM!

[lewing]

Looks good other than the comment

[lewing]

Looks good

[kjpou1]

/backport to release/5.0

[github-actions]

Started backporting to release/5.0: https://github.com/dotnet/runtime/actions/runs/297521067