twisted.conch.manhole_ssh.TerminalSessionTransport requires `session` and `write` attributes on an object only documented as being a ProcessProtocol instance

New submission from exarkun <[email protected]>:

`TerminalSessionTransport.__init__` grabs `session` and `write` from the `proto` argument passed to it.  This works for the uses it is currently put to because conch internally invokes `openShell` with an `SSHSessionProcessProtocol` which extends `ProcessProtocol` with these attributes.  This is undocumented, though, which complicates testing.

Either the `openShell` documentation should be updated to document the actual interface provided by the object passed to it, or `TerminalSessionTransport` should get the objects it needs by some other means (if one exists - or one should be added if necessary).


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Type     : defect
Component: conch
Keywords : 
Priority : normal
Nosy     : 
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http://twistedmatrix.com/trac/ticket/3864