ConPTY Version probing

[patrickbkr]

This is more of a question than a feature request.

I'm currently working on adding PTY support to libuv. Bundling ConPTY is not an option, so I have to work with the version kernel32.dll gives me. There are some relevant developments in the last few years/months.

• Support for Overlapped IO (#17510)
• ConptyReleasePseudoConsole (#14544)
• Probably a few more

How do I know which features are available in the ConPTY version bundled with Windows? Is there some version number I can retrieve? Is there a Matrix of Windows version and ConPTY version?

Also: Is there any documentation on how to use these older ConPTY versions? I find it pretty difficult to find any in-depth information on this. For example, here are some of the questions I've stumbled over:

• Do I have to use synchronous pipes for in and out? (I think: Yes in older versions, no in recent versions.)
• Can I use the same (bidirectional) pipe for PTY in and out? (I think: Yes.)
• Do I have to perform stdin writing and stdout reading each on their own thread? (I think: No.)
• What's happening when I close the pty write handle? (I think: ConPTY sends a CTRL-C to the process.)
• How do I properly shut down a ConPTY session? (According to this comment and this remark, it's a pretty delicate dance I have to perform.)