Re: Lost process output in pipe between Emacs and CVS

[Stefan Monnier]

Thanks Ian for your help.  I'm rather glad to hear that it can be
reproduced outside of Emacs since I can now lay the blame on someone
else (people used to say "it doesn't work in PCL-CVS but it works with
VC so it must be a problem with PCL-CVS" ;-).

> >     CVS uses stdio, and stdio doesn't work very well with non-blocking
> >     file descriptors.  CVS can detect the error easily enough, but at that
> >     point stdio has already thrown away the buffer full of data, and CVS
> >     hasn't recorded it anywhere.  While in principle CVS could switch to
> >     not use stdio, that would be a fairly substantial change.

My Unix programming is a bit rusty, so could someone explain to me
why SSH changing the blocking status of its file-descriptor would
have any impact on CVS' file-descriptor ?  I understand the notion
of duplicating/sharing file-descriptors, but I would expect the
"blocking" status of a file-descriptor to be per-process rather than
global to all processes sharing that file-descriptor.


        Stefan