-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)
- / / / no ref refers to this: we
- --#-----#-------#-----> upstream reconstruct its identity by
- inspecting interchange branch
- 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
+ pseudomerges, turning ...B3 into ...@-A-1-2-B3. (This should
make a note, in your .git/ somewhere, of the original branch
tip so that it can be overwritten with a pseudomerge.)
* 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.
+ changes come first, turning -@-A-1-2-B3 into ...@-A-B-1-2-3.
* New upstream rebase: Start rebasing onto a new upstream version,
- turning ...#..p-A-B-1-2-3 into (...#..p-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.
+ turning ...#..@-A-B-1-2-3 into (...#..@-A-B-|...#'-)@'-1-2. This
+ would be a wrapper around git-rebase, which prepares @' and then
+ tries to rebase 1 2 onto @'. So if you ask for an interactive
+ rebase @' doesn't appear in your commit list.
- Note that the construction of p' cannot fail because p' simply
+ Note that the construction of @' cannot fail because @' 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.)
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?
dgit import handling
--------------------
-
-Consider a non-dgit NMU followed by a dgit NMU:
-
-
-
- interchange --/--B3!--%--/----D*-->
- / /
- % 4
- / 3
- / 2
- / 1
- 2* &_
- / /| \
- 1 0 00 =XBC%
- /
- /
- --p--A breakwater
- /
- --#--------> upstream
-
-
- Key:
-
- =XBC% dgit tarball import of .debian.tar.gz containing
- Debian packaging including changes B C and patches
-
- 0 dgit tarball import of upstream tarball
- 00 dgit tarball import of supplementary upstream tarball
- &_ dgit nearly-breakwater import
- &' git-debrebase converted import (upstream files only)
- D' git-debrebase converted debian/ changes import
-
- * ** before and after HEAD
-
-Want to transform this into:
-
- I. No new upstream version (0 + 00 eq #)
-
- --/--B3!--%--/------D*-------------/-->
- / / /
- % 4 4**
- / 3 3
- / 2 2
- / 1 1
- 2* &_ /
- / /| \ /
- 1 0 00 =XBC% /
- / /
- / /
- --p--A-----B-----------------------C--D
- /
- --#----------------------------------------->
-
-
- II. New upstream (0 + 00 neq #)
-
- --/--B3!--%--/------D*-------------/-->
- / / /
- % 4 4**
- / 3 3
- / 2 2
- / 1 1
- 2* &_ /
- / /| \ /
- 1 0 00 =XBC% /
- / /
- / /
- --p--A-----B--------------------p--C--D
- / /
- --#----------------------- - - / - - ----->
- /
- &'
- /|
- 0 00
~ianmdlvl / dgit.git / blobdiff