X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=NOTES.git-debrebase;h=09237d5973cda501e24ecb4acb4b73c7e4a45a51;hb=8bce000d9c9af3912aeefe1f3874ce3b125cae04;hp=cafab1a771f61f681a6380039f15b6f012537d4e;hpb=9156ead35a760f394274c4b33e9a8f019e712f6d;p=dgit.git diff --git a/NOTES.git-debrebase b/NOTES.git-debrebase index cafab1a7..09237d59 100644 --- a/NOTES.git-debrebase +++ b/NOTES.git-debrebase @@ -1,8 +1,4 @@ TODO - test case for new-upstream-v0 - - --anchor option to specify commit(s) to treat as as anchor(s) - reference docs git-debrebase(5) data model git-debrebase(1) command line @@ -10,36 +6,11 @@ TODO dgit-maint-debrebase(7) someone should set branch..mergeOptions to include --ff-only ? - clean up remains of NOTES and README + clean up remains of README arrange for dgit to automatically stitch on push -# 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-ffqrebase finish -# git-ffqrebase status [BRANCH] -# -# refs/ffq-prev/REF relates to refs/REF -# -# git-debrebase without start, if already started, is willing -# to strip pseudomerges provided that they overwrite exactly -# the previous HEAD -# xxxx is this right ? what matters is have we pushed -# I think in fact the right answer is: -# git-debrebase always strips out pseudomerges from its branch -# a pseudomerge is put in at the time we want to push -# at that time, we make a pseudomerge of the remote tracking -# branch (if raw git) or the dgit view (if dgit) -# for raw git git-ffqrebase, do want preciseley to record -# value of remote tracking branch or our branch, on start, so we -# overwrite only things we intend to -# the previous pseudomerge check for tags and remote branches ? - - -========= +======================================= special commit tags overall format @@ -73,8 +44,7 @@ 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 @@ -83,130 +53,79 @@ workflow 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! - -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. - -Actually this is not special to PMs. - -We need to record a new to-be-overwritten commit - merge-base( our branch tip, relevant remote ) - -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. - - - -How about +======================================== - git-debrebase start or git-debrebase [continue] +Theory for ffq-prev - with no recorded will-overwrite + refs/ffq-prev/REF relates to refs/REF - 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 +When we strip a pm, we need to maybe record it (or something) as the +new start point. - 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. +When we do a thing - other model: - merge-base( current remote, current tip ) + with no recorded ffq-prev - it is safe to overwrite current tip, by the - argument above + ffq-prev is our current tip - it is always safe to rewind will-overwrite: all - that does is overwrite _less_ stuff + 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 is the earliest overwrite we can make that - will be pushable to the remote + 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. - 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. + also we can explicitly preserve with + git-debrebase stitch - this model tends to rewind and rebase ad-hoc commits - made on our tip branch before we did rebase start, - this is better + It is always safe to rewind ffq-prev: all + that does is overwrite _less_ stuff. - in any case putative will-overwrite must be ff from remote. + 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 will-overwrite. So if we spot - this, report an error. + made pseudomerge to overwrite ffq-prev. So if we spot + this, report an error. see above - with a recorded will-overwrite + with a recorded ffq-prev - we may need to advance will-overwrite, to allow us to generate + we may need to advance ffq-prev, to allow us to generate future pseudomerges that will be pushable - advancing will-overwrite is dangerous, since it might + advancing ffq-prev is dangerous, since it might effectively cancel the commits that will-ovewrite is advanced over. - we advance it to 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 -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. - -Is that actually true ? What if the user actually _wanted_ to keep -the pseudomerge despite not having pushed it ? - -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. - -======================================== + currently this is not implemented -So, pm handling specifics: + better maybe to detect divergence ? but it is rather late + by then! -strategy is to avoid making needless pseudomerges -pseudomerges that exist will be preserved -(by being included in will-overwrite) +We check we are ff from remotes before recording new ffq-prev -This is good because the presence of a pseudomerge means we know we -want to keep it; and that allows explicit control over history detail -level. - -It does mean we must avoid making the pseudomerges unnecessarily. -They should be made just before (ideally, part of) dgit push. + ---------- now follows much the same info in different words ---------- 1. git-debrebase [-i etc.] should: - check for will-overwrite - if is already a will-overwrite, fine, do no more + check for ffq-prev + if is already a ffq-prev, fine, do no more if not: check our origin branch exists and we are ff from it @@ -216,7 +135,7 @@ They should be made just before (ideally, part of) dgit push. check we are ff from them if not fail - set will-overwrite to something which is ff from + set ffq-prev to something which is ff from all above branches we use our tip, as discussed above @@ -229,11 +148,15 @@ N. git-debrebase [--noop-ok] record-ffq-prev 2. git-debrebase [--noop-ok] stitch - makes pseudomerge with will-overwrite - deletes will-overwrite + makes pseudomerge with ffq-prev + deletes ffq-prev we will teach dgit to do git-debrebase stitch + or some such ? + +following parts are not implemented and maybe aren't the +best subcommand names etc. 3. git-debrebase push @@ -245,45 +168,20 @@ N. git-debrebase [--noop-ok] record-ffq-prev stiches, finalises changelog, signs tags, pushes everything for the future, when there is some automatic builder -will-overwrite 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..HEAD: 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 +that is what is currently implemented ======================================== -divergence, merges: +how to handle divergence and merges (if not detected soon enough) same problem if merge, look at branches before merge @@ -320,3 +218,15 @@ current avaiable strategies: 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 ? + +======================================== + +For downstreams of Debian, sketch of git-ffqrebase + +# 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-ffqrebase finish +# git-ffqrebase status [BRANCH]