+TODO
+ reference docs
+ git-debrebase(5) data model
+ git-debrebase(1) command line
+ tutorial
+ dgit-maint-debrebase(7)
+ someone should set branch.<name>.mergeOptions to include --ff-only ?
+
+ clean up remains of NOTES and README
+
+ arrange for dgit to automatically stitch on push
+
+========================================
+
+# refs/ffq-prev/REF relates to refs/REF
+
+=======================================
+
+special commit tags
+overall format
+ [git-debrebase[ COMMIT-TYPE [ ARGS...]]: PROSE, MORE PROSE]
+
+[git-debrebase: split mixed commit, debian part]
+[git-debrebase: split mixed commit, upstream-part]
+[git-debrebase: convert dgit import, debian changes]
+[git-debrebase anchor: convert dgit import, upstream changes]
+
+[git-debrebase upstream-combine . PIECE[ PIECE...]: new upstream]
+[git-debrebase anchor: new upstream NEW-UPSTREAM-VERSION, merge]
+[git-debrebase: new upstream NEW-UPSTREAM-VERSION, changelog]
+
+[git-debrebase convert-from-gbp: drop patches]
+[git-debrebase anchor: declare upstream]
+[git-debrebase pseudomerge: stitch]
+
+[git-debrebase convert-to-gbp: commit patches]
+
+m{^\[git-debrebase (?:\w*-)?upstream combine \.((?: $extra_orig_namepart_re)+)\]}
+
+Every anchor commit must be a merge. In principle, this is not
+necessary. After all, we are relying on the
+ [git-debrebase anchor: ...]
+commit message annotation in "declare" anchor merges (which
+do not have any upstream changes), to distinguish those anchor
+merges from ordinary pseudomerges (which we might just try to strip).
+
+However, the user is going to be doing git-rebase a lot. We really
+don't want them to rewrite an anchor commit. git-rebase
+trips up on merges, so that is a useful safety catch.
+
+=======================================
+
workflow
git-debrebase blah [implies start] strips pseudomerge(s)
commit / git-debrebase / etc.
dgit --damp-run push
- hook: call git-debrebase prep-push adds new pm ? passes --overwrite ?
- dgit push does not update remote
+ hook: call git-debrebase prep-push dgit push does not update remote
+ or something, must add patches at least
- commit / git-debrebase / etc. strips pm(s) including last one
+ commit / git-debrebase / etc. strips patches
dgit push
- hook: call git-debrebase prep-push adds new pm ? passes --overwrite ?
- dgit push DOES update remote
+ hook: call git-debrebase prep-push dgit push DOES update remote
commit / git-debrebase / etc. strips last pm, but arranges
that remade pm will incorporate it
-Aha!
+========================================
+
+Theory for ffq-prev
When we strip a pm, we need to maybe record it (or something) as the
new start point.
-We do this if the pm is contained within the output branch.
+When we do a thing
-Actually this is not special to PMs.
+ with no recorded ffq-prev
-We need to record a new to-be-overwritten commit
- merge-base( our branch tip, relevant remote )
+ ffq-prev is our current tip
-If this is not a descendant of the relevant remote, then we are going
-to have a problem when we push so issue a warning or fail.
+ obviously it is safe to say we will overwrite this
+ we do check whether there are not-included changes in the remotes
+ because if the new ffq-prev is not ff from the remotes
+ the later pushes will fail
+ this model tends to keep ad-hoc commits made on our
+ tip branch before we did rebase start, in the
+ `interchange view' and also in the rebase stack.
+ also we can explicitly preserve with
+ git-debrebase stitch
-How about
+ It is always safe to rewind ffq-prev: all
+ that does is overwrite _less_ stuff.
- git-debrebase start or git-debrebase [continue]
+ in any case putative ffq-prev must be ff from remote.
+ Otherwise when we push it will not be ff, even though we have
+ made pseudomerge to overwrite ffq-prev. So if we spot
+ this, report an error. see above
- with no recorded will-overwrite
+ with a recorded ffq-prev
- putative will-overwrite is
- one model:
- our current tip
- obviously it is safe to say we will overwrite this
- we do not need to worry about whether this will
- overwrite not-included changes in the remote
- because either the will-overwrite is not
- ff from the remote (in which case later failure,
- see below); or the will-overwrite _is_ ff
- from the remote ie our tip is later than the
- remote and includes all of its changes
+ we may need to advance ffq-prev, to allow us to generate
+ future pseudomerges that will be pushable
- this model tends to keep ad-hoc commits made on our
- tip branch before we did rebase start, in the
- `interchange view' and also in the rebase stack.
+ advancing ffq-prev is dangerous, since it might
+ effectively cancel the commits that will-ovewrite is advanced
+ over.
- other model:
- merge-base( current remote, current tip )
+ ??? advance it to merge-base( current remote, current tip )
+ if possible (see above), - ie to current remote, subject
+ to the condition that that is an ancestor of current tip
- it is safe to overwrite current tip, by the
- argument above
+ currently this is not implemented
- it is always safe to rewind will-overwrite: all
- that does is overwrite _less_ stuff
+ better maybe to detect divergence ? but it is rather late
+ by then!
- this is the earliest overwrite we can make that
- will be pushable to the remote
+We check we are ff from remotes before recording new ffq-prev
- in practical terms this can only be ff from the
- current remote if it is equal to the current remote;
- so what we are actually checking below is that our tip
- is ff from the remote. This ought to be true before
- the first of our rebases.
+ ---------- now follows much the same info in different words ----------
- this model tends to rewind and rebase ad-hoc commits
- made on our tip branch before we did rebase start,
- this is better
+1. git-debrebase [-i etc.]
- in any case putative will-overwrite must be ff from remote.
- Otherwise when we push it will not be ff, even though we have
- made pseudomerge to overwrite will-overwrite. So if we spot
- this, report an error.
+ should:
+ check for ffq-prev
+ if is already a ffq-prev, fine, do no more
+ if not:
- with a recorded will-overwrite
+ check our origin branch exists and we are ff from it
+ if not fail
- we may need to advance will-overwrite, to allow us to generate
- future pseudomerges that will be pushable
+ check our other might-be-pushed to branches
+ check we are ff from them
+ if not fail
- advancing will-overwrite is dangerous, since it might
- effectively cancel the commits that will-ovewrite is advanced
- over.
+ set ffq-prev to something which is ff from
+ all above branches
- we advance it to merge-base( current remote, current tip )
- if possible (see above), - ie to current remote, subject
- to the condition that that is an ancestor of current tip
+ we use our tip, as discussed above
+ (optionally, can use some other commit which is ff
+ from all of the above, eg one of them)
+
+N. git-debrebase [--noop-ok] record-ffq-prev
+
+ does what is described above
+
+2. git-debrebase [--noop-ok] stitch
+
+ makes pseudomerge with ffq-prev
+ deletes ffq-prev
+
+ we will teach dgit to do
+ git-debrebase stitch
+
+3. git-debrebase push
+
+ like git push only does stitch first
+ ??? command line parsing!
+
+4. git-debrebase release
+
+ stiches, finalises changelog, signs tags, pushes everything
+ for the future, when there is some automatic builder
+
+ffq-prev for each ref
+ refs/heads/FOO
+is
+ refs/ffq-prev/FOO
+
+========================================
+
+import from gbp
+
+[ all this is done now:
+ inputs:
+ current HEAD (patches-unapplied),
+ this is going to be the base of the old breakwater
+ nominated upstream
+
+ checks:
+ HEAD:<upstream> = upstream:<upstream>
+ upstream..HEAD:<upstream> is empty (overrideable)
+ upstremm:debian is empty (overrideable)
+
+ procedure:
+ construct
+ run gbp pq import to generate pq branch
+ new breakwater is
+ old HEAD
+ commit to remove d/patches
+ anchor merge with upstream
+ "rebase" of pq branch, each commit with d/patches stripped
+]
+
+what about dgit view branch ?
+ideally, would make pseudomerge over dgit view
+would need to check that dgit view is actually dgit view of
+ ond of our ancestors
+failing that first push will need --overwrite
+
+========================================
+
+how to handle divergence and merges (if not detected soon enough)
+
+same problem
+ if merge, look at branches before merge
+ generate new combined branch
+ pseudomerge to overwrite merge
+
+current avaiable strategies:
+
+ maybe launder foreign branch
+
+ if foreign branch is nmuish, can rebase it onto ours
+
+ could merge breakwaters (use analyse to find them)
+ merge breakwaters (assuming same upstream)
+ manually construct new patch queue by inspection of
+ the other two patch queues
+
+ instead of manually constructing patch queue, could use
+ gbp pq export and git merge the patch queues
+ (ie work with interdiffs)
+
+ if upstreams are different and one is ahead
+ simply treat that as "ours" and
+ do the work to import changes from the other
-In each case we can strip pseudomerges freely, as needed. We do not
-want to record what pseudomerges we strip, because whether we need to
-keep them depends (only) on whether they have been pushed.
+ if upstreams have diverged, can
+ resolve somehow to make new upstream
+ do new-upstream on each branch separately
+ now reduced to previously "solved" problem
-Is that actually true ? What if the user actually _wanted_ to keep
-the pseudomerge despite not having pushed it ?
+ in future, auto patch queue merge algorithm
+ determine next patch to apply
+ there are three versions o..O, l..L, r..R
+ we have already constructed m (previous patch or merged breakwater)
+ try using vector calculus in the implied cube and compute
+ multiple ways to check consistency ?
-In that case we need to advance will-overwrite past it. We could
-provide an explicit command to do this: it would advance
-will-overwrite to the current tip (see rules above, which show that
-this is OK). Or maybe to the last pseudomerge on the current tip,
-so that the overall result will be series of pseudomerges.
+========================================
+# git-ffqrebase start [BASE]
+# # records previous HEAD so it can be overwritten
+# # records base for future git-ffqrebase
+# git-ffqrebase set-base BASE
+# git-ffqrebase <git-rebase options>
+# git-ffqrebase finish
+# git-ffqrebase status [BRANCH]
~ianmdlvl / dgit.git / blobdiff