Before talk:
- cd ~/src/helm
- reset to what I dgit pushed most recently (6282cfd4)
- open =gitk --first-parent=
- ensure the git stash is poppable on top of the right commit

Demo:
- from the "Update to upstream 2.9.7 commit" onwards, describe the commits
  + mixture of packaging commits, patches to upstream, auto commits
  + the top two commits pseudomerge over previous upload
  + that happened because I only just switched this package to use
    git-debrebase

- note that in this example the patches do not appear at the end of
  the history.  This is because I did not debrebase before uploading.

- run: =git log --oneline v2.9.7..debian/2.9.7-1 -- . ':!debian'=

- we can see that there are four commits that change the upstream
  source, i.e. we have a delta queue of length 4

- now: magit log on the file README.md to show how it's a completely
  normal git log with the Debian commit on the top

- my goal for this demo here is to make a change to the upstream
  source, and then rearrange the delta queue such that this change
  appears second in the queue, right before the README decruft
  + you might want to do this because you want to add other patches
    that build on this one

- I prepared a commit to patch the upstream source and add a changelog
  entry, I'll just pop it from my git stash stack

- let's commit
  + =git diff=
  + =git commit -a -m "be more excited about helm"=

- refresh gitk and show the new mixed commit

- alright, now it's time to debrebase because things are a bit of a mess
  + =git debrebase -i=
  + move the commit to the right place, =C-c C-c=
  + refresh gitk
  + count the five commits to upstream source and look at the change
    we made
  + we now have two "be more excited by helm" commits
  + and the auto commit of debian/patches has been stripped out
  + and the delta queue is at the end of the branch

- from here, you can type =dgit push-source= to upload, and you will
  get a =debian/patches= that exactly matches these five commits

- or if we need to push to salsa, =git debrebase conclude= will get us
  something that is a fast-forward of what we had before
  + kill gitk
  + git debrebase conclude
  + gitk --date-order
  + now we see exactly what we had before =git debrebase conclude=
    except it is a FF of what we had before, so we can push to salsa

Prep:
- Cables.
- Check readability of gitk, term and Emacs -- might want to bump font sizes.

-- 
Sean Whitton