Why do remote programs crash with X Error of failed request: BadAtom? Why do remote programs exit when you try to copy and paste?
This question should be obsolete since the security extension is now disabled OpenSSH 3.8 enables untrusted X11 forwarding by default when connecting to an ssh server that supports untrusted X11Forwarding. Most ssh servers for GNU/Linux are versions of OpenSSH that do support untrusted X11Forwarding, so using OpenSSH from Cygwin will result in a connection that uses untrusted X11Forwarding by default. You will quickly notice that this is the case if most of your X applications are now killed when you try to copy and paste or if xdpyinfo returns only a fraction of the supported extensions that it does if run locally. It is easiest to just override untrusted X11Forwarding by passing -Y to ssh in place of -X. The -Y does the same thing as -X, but it enables trusted X11Forwarding for the current connection. Starting with OpenSSH 3.8 you will need to set “ForwardX11Trusted yes” in the client configuration to allow remote clients full access to the xserver.
