dagop: fix subsetparentswalker to set p1/p2 chains at merge revision
The previous implementation was wrong because the '1'/'2' key would be
appended at a fork revision. Since we traverse the graph from heads, a merge
revision is actually a branching point, where the sort key must be generated.
#require no-windows
$ . "$TESTDIR/remotefilelog-library.sh"
$ cat >> $HGRCPATH <<EOF
> [extensions]
> remotefilelog=
> share=
> EOF
$ hg init master
$ cd master
$ cat >> .hg/hgrc <<EOF
> [remotefilelog]
> server=True
> EOF
$ echo x > x
$ hg commit -qAm x
$ cd ..
$ hgcloneshallow ssh://user@dummy/master source --noupdate -q
$ hg share source dest
updating working directory
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg -R dest unshare