Are remote pipes fixed in 3.5?

Trolling through the mailing list archives, I've found both on the developer list as well as this list questions about remote pipes causing problems with SSH2 (but not SSH1) connections. The problem I'm talking about is this:

ssh -2 remotehost yes | dd of=/dev/null count=2

This will hang. the 'yes' program running on remotehost will block, and ssh will never return. dd will have exited. Using -1 will work fine. Basically, SSH2 will shut down the channel without telling the remote side that stdout has closed. Note that you can play all sorts of games with -n and -f, but nothing fixes it (if you use -f, the dd will exit and it will "appear" to work, but actually all that happens is the ssh is running in the background, and the remote 'yes' is still running (though blocked)).

ssh -v -v -v output:

...

debug1: Sending command: yes
debug1: channel request 0: exec
debug2: callback done
debug1: channel 0: open confirm rwindow 0 rmax 16384
debug2: channel 0: rcvd adjust 32768
debug1: channel 0: write failed
debug1: channel 0: close_write
debug1: channel 0: output open -> closed
debug1: channel_free: channel 0: client-session, nchannels 1
debug3: channel_free: status: The following connections are open:

Nicholas William's post on the developer list in December of 2001 said something about a patch needing to be applied to nchan.c in chan_failed_write2(). So, is this fixed in 3.5? I think the developers agree that shutting down the connection is the right thing to do (it's what rsh does), so I just need to know if it's in 3.5 to make it worth upgrading from Solaris 9's ssh.

What I'm trying to do is the ubiquitous backup-over-ssh, and end of tape detection is driving me nuts. Something as simple as:

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ssh host ufsdump / | dd od=/dev/rmt/0

WILL NEVER END when the tape runs out. Sigh.

Sean

PS If this is not fixed, I'll post to the developer list. . . Received on Thu Jan 23 11:02:23 2003