`tg next` returns the wrong next topic

[matttbe]

Hello,

First, thank you for maintaining this great tool!

I have an issue with tg next returning a wrong topic: the returned topic is from another part of the tree.

My TopGit tree is mostly linear:

$ tg summary --rdeps-full t/DO-NOT-MERGE-git-markup-fixes-net-next
t/DO-NOT-MERGE-git-markup-fixes-net-next
  t/DO-NOT-MERGE-git-markup-net-next
    net-next
  t/DO-NOT-MERGE-git-markup-end-common-net-net-next
    (...)
            t/DO-NOT-MERGE-git-markup-net
              net

Or:

              t/upstream                                     t/upstream-net
                   ↓                                                ↓
                 (...)                                            (...)
                   ↓                                                ↓
t/DO-NOT-MERGE-git-markup-fixes-net-next  →  t/DO-NOT-MERGE-git-markup-end-common-net-net-next
                   ↓                                                ↓
  t/DO-NOT-MERGE-git-markup-net-next                              (...)
                   ↓                                                ↓
                net-next                              t/DO-NOT-MERGE-git-markup-net
                                                                    ↓
                                                                   net

Here is the issue:

$ git checkout t/DO-NOT-MERGE-git-markup-net-next
$ tg next
t/DO-NOT-MERGE-git-markup-net

If I insert another topic between t/DO-NOT-MERGE-git-markup-net-next and t/DO-NOT-MERGE-git-markup-fixes-net-next, it is only from this topic I have an issue and t/DO-NOT-MERGE-git-markup-net is returned.

Here is the output of sh -x /usr/bin/tg next 2>&1 | sed "s#${PWD}#/PWD#g" > tg-next.log (my PWD is very long, I reduced it): tg-next.log

You can easily experiment this issue because my repo is public: https://github.com/multipath-tcp/mptcp_net-next/