Add System.Messaging sources

[karelz]

Code for System.Messaging

[karelz]

@terrajobst can you please merge it?
cc @HongGit @HeathAr @dasetser

[KalleOlaviNiemitalo]

A note to anyone intending to reuse this code.

System.Messaging.MessageQueue.GetSecurityContext() always throws MissingMethodException because SecurityContextHandle lacks a parameterless (perhaps private) constructor that Platform Invoke would call here:

referencesource/System.Messaging/System/Messaging/Interop/NativeMethods.cs

Lines 320 to 334 in 08847a3

	// This call is here because we don't want to invent a separate MessageQueuePermission
	// for this call, and there's no suitable existing permission.
	[DllImport(ExternDll.Mqrt, EntryPoint = "MQGetSecurityContextEx", CharSet = CharSet.Unicode)]
	private static extern int IntMQGetSecurityContextEx(IntPtr lpCertBuffer, int dwCertBufferLength, out SecurityContextHandle phSecurityContext);
	public static int MQGetSecurityContextEx(out SecurityContextHandle securityContext)
	{
	try
	{
	return IntMQGetSecurityContextEx(IntPtr.Zero, 0, out securityContext);
	}
	catch (DllNotFoundException)
	{
	throw new InvalidOperationException(Res.GetString(Res.MSMQNotInstalled));
	}
	}

I don't expect the bug to be fixed in .NET Framework (reported to connect.microsoft.com in 2010) or in Reference Source, but perhaps it can be fixed in the .NET Core port.

[karelz]

@terrajobst can we merge it please?
cc @danmosemsft

[danmoseley]

@karelz is there a code owner that can sign off here, for the sake of process?

I have merge powers and can do that.

[danmoseley]

Can we also tag the person who originally requested this, so they can confirm everything's here?

[weloytty]

Can we also tag the person who originally requested this, so they can confirm everything's here?

@danmosemsft I am not sure if you mean someone internal to MSFT, but I am the one who sent the original email after @karelz asked me to in dotnet/runtime#16409 (comment) , and everything I need is in the commit.

[karelz]

@danmosemsft code owners in .NET Framework are tagged above: #141 (comment)

[danmoseley]

OK - @HongGit @HeathAr @dasetser could one of you please sign off?

[danmoseley]

Done! Hope this is what you need @weloytty and apologies for the time it took.

[weloytty]

Thanks everyone for all of your help, I built everything and made the repo public, and just submitted to nuget a few minutes ago. This was a huge roadblock for us, I'm glad that we won't be stuck on .NET Framework forever.

[danmoseley]

Nice! cc @mconnew fyi.

[mconnew]

There's going to be some features in this which are broken. For example, you can use transactions with MSMQ but the implementation of System.Transactions in .NET Core doesn't work with MSDTC so that part of System.Messaging won't work. I'm not super familiar with the code base or even api so I'm not volunteering, but someone should go through the features supported by the api and work out what does and doesn't work and throw PlatformNotSupportedException on things which don't work instead of having everyone who consumes this api try and work out why their app isn't working as expected.
Nevermind, just saw this is making the code available in reference source. I thought this was in dotnet/runtime