ProxyJump may construct erroneous ProxyCommand

[Damien Miller]

On Mon, 15 Jan 2024, Damien Miller wrote:

> On Sat, 13 Jan 2024, Rob Leslie wrote:
> 
> > Hello,
> > 
> > On macOS, Terminal’s “New Remote Connection…” command runs ssh in a new window like this:
> > 
> > 	login -pfq $USER /usr/bin/ssh $HOST
> > 
> > Here, login executes /usr/bin/ssh with argv[0] set to “-ssh”.
> > 
> > If $HOST has a ProxyJump configuration, the resulting ProxyCommand is:
> > 
> > 	-ssh -W '[%h]:%p' $JUMP_HOST
> > 
> > Because of the leading hyphen, this fails to execute. If the user’s shell is zsh, the Terminal window shows:
> > 
> > 	zsh:1: unknown exec flag -s
> > 
> > Would it make sense to ignore any leading hyphen when constructing the ProxyCommand from ProxyJump?
> > 
> > % ssh -V       
> > OpenSSH_9.4p1, LibreSSL 3.3.6
> 
> This sounds more like a problem in OSX Terminal.app than ssh. We could do
> something like this:

actually, that won't work at all :(