On 4 March 2010 17:46, Bo Shi <bs1...@gmail.com> wrote: > Hi All, > > I've been struggling with this issue off and on for the better part of > a month now. Having implemented a simple git SSH server using some of > the Conch examples in the official documentation, I encountered an > issue that would cause a git client to throw an error only part of the > time.
I think it's a bug in conch. > The little program to reproduce the issue is found at > > http://gist.github.com/321403 > > (raw version for download) > > http://gist.github.com/raw/321403/82ab2111a2709c8fe50a77aabb08565749087408/gitconnbug.py > > and can be executed to start the sample server. Run a command like > > # The /abspath/to/git/repo should be readable by the server user > $ git clone ssh://u...@localhost:2222/abspath/to/git/repo > (password "user") > > To test the server. On my workstation, I am able to reproduce the > error at least once every 5 tries. It's definitely not consistent. > The behavior I see is attached at the end of this email. The client > fails due to a premature inConnectionLost() call in the > SSHSessionProcessProtocol that sends an EOF. > > As a workaround, when TraceProcessProtocol.inConnectionLost() is > overriden to do nothing, the client error goes away. This is somewhat > foreign territory for me so I'm not sure whether it's a bug in git or > whether it's a bug in the twisted ProcessProtocol implementation. RFC > 4254 isn't terribly helpful here: > > 5.3. Closing a Channel > > When a party will no longer send more data to a channel, it SHOULD > send SSH_MSG_CHANNEL_EOF. > > So on the surface the current behavior of sending an EOF appears fine, > however, I can't really find any definitive cases of this type of > problem popping up via, say, default OpenSSH/git combinations. > > > Any advice? Is the gitconnbug.py implementation flawed? Should I > open a ticket? Any git experts know of a case where git-upload-pack > might close it's stdout pipe? I think what's actually happening here is that git-upload-pack is closing its *stdin*. Why conch reacts to that by shutting down the channel, I don't really know -- it doesn't seem right to me. Maybe it's a simple logic error and it method should be 'outConnectionClosed' instead? At any rate, I think this is a bug -- please file a ticket. And thanks for the complete example! Cheers, mwh _______________________________________________ Twisted-Python mailing list Twisted-Python@twistedmatrix.com http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
