subrepo: make stdin for svn a pipe for non-interactive use (issue2759) This certainly can't hurt, so go ahead and do it, potentially along with --non-interactive if that flag is safe for the given subcommand.

Ancestors of 5
4 2 0 
Ancestors of 6 and 5
3 4 2 1 0 
Ancestors of 5 and 4
4 2 0 

Descendants of 5
7 8 
Descendants of 5 and 3
6 7 8 
Descendants of 5 and 4
5 7 8