-
-
-My preferred answer is that it is a constantly rebasing branch topped
-with a series of pseudomerges to make it fast-forwarding.
-
- ------/--A!----/--B3!--%--/--> interchange view
- / / / with debian/ directory
- % % % all upstream changes applied
- / / / 3.0 (quilt) has debian/patches
- / / 3*
- / / /
- 2* 2* 2
- / / /
- 1 1 1 `breakwater' branch, merging baseline
- / / / unmodified upstream code
- ---p-----p--A----p--B--C--> plus debian/ (but no debian/patches)
- / / /
- --#-----#-------#-----> upstream
-
- Key:
-
- 1,2,3 commits touching upstream files only
- A,B,C commits touching debian/ only
- B3 mixed commit (eg made by an NMUer)
- # upstream releases
-
- -p- special merge, takes contents of debian/ from the
- / previous `breakwater' commit and rest from upstream
-
- -/- pseudomerge; contents are identical to
- / parent lower on diagram.
-
- % dgit-generated commit of debian/patches.
- `3.0 (quilt)' only; dropped by rebase tool.
-
- * Maintainer's HEAD was here while they were editing,
- before they said they were done, at which point their
- tools generated [% and] -/- commit[s] to convert to
- the fast-forwarding interchange branch. (Maybe the
- tooling is simply `dgit push'.)
-
- ! NMUer's HEAD was here when they said `dgit push'.
- Rebase branch launderer turns each ! into an
- equivalent *.
-
-
-Looking from the tip of the interchange view, it is I think always
-possible to classify these commits appropriately: pseudomerges are
-fairly obvious (if all three trees are identical, we descend to the
-parent with the most recent commit date), and the `p' special merge is
-the only non-pseudo merge and has a special form.
-
-So it would be possible to write a `git-debrebase' tool which would
-take (for example) B4, above, and be able to perform functions like:
-
- * Strip pseudomerges: Rewrite the current branch so it contains no
- pseudomerges, turning ...B3 into ...p-A-1-2-B3. (This should
- make a note, in your .git/ somewhere, of the latest pseudomerge to
- be deleted.)
-
- * Cleanup branch: Reorganise the current branch so that the debian/
- changes come first, turning -p-A-1-2-B3 into ...p-A-B-1-2-3.
-
- * New upstream rebase: Start rebasing onto a new upstream version,
- turning ...#...p-A-B-1-2-3 into ...#'.A-B-p'-1-2. This would be a
- wrapper around git-rebase, which prepares p' and then tries to
- rebase 1 2 onto p'. So if you ask for an interactive rebase p'
- doesn't appear in your commit list.
-
- Note that the rebasing of p into p' cannot fail because p' simply
- copies debian/ from B and and everything else from #'. (Rebasing A
- and B is undesirable. We want the debian/ files to be non-rebasing
- so we can `git log' and get the packaging history.)
-
- * Record pseudomerge. This is like "committing" your patch queue.
- The LH parent is taken from the previous strip pseudomerge. (We
- should probably check that this is consistent with what we see in
- debian/changelog, but that is not a sufficient check.)
-
-Maybe some of these operations should automatically edit
-debian/changelog.
-
-The only thing that this can't easily do is permit nonlinear (ie,
-merging) history on the `packaging-only' branch, because upstream
-might contain debian/ files too, so it is not possible to distinguish
-a merge of two `packaging-only' branches from the special merge `p'.
-(Indeed I since upstream might copy debian/ from us, I think it is not
-easy to reliably distinguish the two parents of a `p'. In the most
-exciting edge case, upstream might `git merge' a previous instance of
-our interchange view, but I think even then everything still works.)
-
-Sean Whitton writes ("Re: Feedback on 3.0 source format problems"):
-> Does the [breakwater] branch contain debian/ alone?
-
-No, it also contains a complete unmodified copy of the upstream code.
-(Except that if upstream had a debian/ directory, it is completely
-replaced.)
-
-For `3.0 (quilt)' the breakwater branch contains roughly what you
-would get if you untarred the origs and the debian.tar.gz, and then
-deleted all the patches without applying them.
~ianmdlvl / dgit.git / blobdiff