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Diffstat (limited to 'Documentation/howto/maintain-git.txt')
| -rw-r--r-- | Documentation/howto/maintain-git.txt | 227 |
1 files changed, 171 insertions, 56 deletions
diff --git a/Documentation/howto/maintain-git.txt b/Documentation/howto/maintain-git.txt index d07c6d44e5..45e2599c5d 100644 --- a/Documentation/howto/maintain-git.txt +++ b/Documentation/howto/maintain-git.txt @@ -37,22 +37,20 @@ The Policy The policy on Integration is informally mentioned in "A Note from the maintainer" message, which is periodically posted to -this mailing list after each feature release is made. +the mailing list after each feature release is made: - Feature releases are numbered as vX.Y.0 and are meant to contain bugfixes and enhancements in any area, including functionality, performance and usability, without regression. - - One release cycle for a feature release is expected to last for - eight to ten weeks. - - - Maintenance releases are numbered as vX.Y.Z and are meant + - Maintenance releases are numbered as vX.Y.Z (0 < Z) and are meant to contain only bugfixes for the corresponding vX.Y.0 feature release and earlier maintenance releases vX.Y.W (W < Z). - - 'master' branch is used to prepare for the next feature + - The 'master' branch is used to prepare for the next feature release. In other words, at some point, the tip of 'master' - branch is tagged with vX.Y.0. + branch is tagged as vX.(Y+1).0, when vX.Y.0 is the latest + feature release. - 'maint' branch is used to prepare for the next maintenance release. After the feature release vX.Y.0 is made, the tip @@ -63,11 +61,28 @@ this mailing list after each feature release is made. - 'next' branch is used to publish changes (both enhancements and fixes) that (1) have worthwhile goal, (2) are in a fairly good shape suitable for everyday use, (3) but have not yet - demonstrated to be regression free. New changes are tested - in 'next' before merged to 'master'. + demonstrated to be regression free. Reviews from contributors on + the mailing list help to make the determination. After a topic + is merged to 'next', it is tested for at least 7 calendar days + before getting merged to 'master'. - 'seen' branch is used to publish other proposed changes that do - not yet pass the criteria set for 'next'. + not yet pass the criteria set for 'next' (see above), but there + is no promise that 'seen' will contain everything. A topic that + had no reviewer reaction may not be picked up. + + - A new topic will first get merged to 'seen', unless it is + trivially correct and clearly urgent, in which case it may be + directly merged to 'next' or even to 'master'. + + - If a topic that was picked up to 'seen' becomes and stays + inactive for 3 calendar weeks without having seen a clear + consensus that it is good enough to be moved to 'next', the + topic may be discarded from 'seen'. Interested parties are + still free to revive the topic. For the purpose of this + guideline, the definition of being "inactive" is that nobody + has discussed the topic, no new iteration of the topic was + posted, and no responses to the review comments were given. - The tips of 'master' and 'maint' branches will not be rewound to allow people to build their own customization on top of them. @@ -86,10 +101,49 @@ this mailing list after each feature release is made. users are encouraged to test it so that regressions and bugs are found before new topics are merged to 'master'. + - When a problem is found in a topic in 'next', the topic is marked + not to be merged to 'master'. Follow-up patches are discussed on + the mailing list and applied to the topic after being reviewed and + then the topic is merged (again) to 'next'. After going through + the usual testing in 'next', the entire (fixed) topic is merged + to 'master'. + + - One release cycle for a feature release is expected to last for + eight to ten weeks. A few "release candidate" releases are + expected to be tagged about a week apart before the final + release, and a "preview" release is tagged about a week before + the first release candidate gets tagged. + + - After the preview release is tagged, topics that were well + reviewed may be merged to 'master' before spending the usual 7 + calendar days in 'next', with the expectation that any bugs in + them can be caught and fixed in the release candidates before + the final release. + + - After the first release candidate is tagged, the contributors are + strongly encouraged to focus on finding and fixing new regressions + introduced during the cycle, over addressing old bugs and any new + features. Topics stop getting merged down from 'next' to 'master', + and new topics stop getting merged to 'next'. Unless they are fixes + to new regressions in the cycle, that is. + + - Soon after a feature release is made, the tip of 'maint' gets + fast-forwarded to point at the release. Topics that have been + kept in 'next' are merged down to 'master' and a new development + cycle starts. + + Note that before v1.9.0 release, the version numbers used to be structured slightly differently. vX.Y.Z were feature releases while vX.Y.Z.W were maintenance releases for vX.Y.Z. +Because most of the lines of code in Git are written by individual +contributors, and contributions come in the form of e-mailed patches +published on the mailing list, the project maintains a mapping from +individual commits to the Message-Id of the e-mail that resulted in +the commit, to help tracking the origin of the changes. The notes +in "refs/notes/amlog" are used for this purpose, and are published +along with the broken-out branches to the maintainer's repository. A Typical Git Day ----------------- @@ -104,7 +158,7 @@ by doing the following: files in mbox format). - Write his own patches to address issues raised on the list but - nobody has stepped up solving. Send it out just like other + nobody has stepped up to solve. Send it out just like other contributors do, and pick them up just like patches from other contributors (see above). @@ -133,6 +187,43 @@ by doing the following: In practice, almost no patch directly goes to 'master' or 'maint'. + Applying the e-mailed patches using "git am" automatically records + the mappings from 'Message-Id' to the applied commit in the "amlog" + notes. Periodically check that this is working with "git show -s + --notes=amlog $commit". + + This mapping is maintained with the aid of the "post-applypatch" + hook found in the 'todo' branch. That hook should be installed + before applying patches. It is also helpful to carry forward any + relevant amlog entries when rebasing, so the following config may + be useful: + + [notes] + rewriteRef = refs/notes/amlog + + Avoid "cherry-pick", as it does not propagate notes by design. Use + either "git commit --amend" or "git rebase" to make corrections to + an existing commit, even for a single-patch topic. + + Make sure that a push refspec for 'refs/notes/amlog' is in the + remote configuration for publishing repositories. A few sample + configurations look like the following: + + [remote "github"] + url = https://github.com/gitster/git + pushurl = github.com:gitster/git.git + mirror + + [remote "github2"] + url = https://github.com/git/git + fetch = +refs/heads/*:refs/remotes/github2/* + pushurl = github.com:git/git.git + push = refs/heads/maint:refs/heads/maint + push = refs/heads/master:refs/heads/master + push = refs/heads/next:refs/heads/next + push = +refs/heads/seen:refs/heads/seen + push = +refs/notes/amlog + - Review the last issue of "What's cooking" message, review the topics ready for merging (topic->master and topic->maint). Use "Meta/cook -w" script (where Meta/ contains a checkout of the @@ -149,6 +240,10 @@ by doing the following: $ git diff ORIG_HEAD.. ;# final review $ make test ;# final review + If the tip of 'master' is updated, also generate the preformatted + documentation and push the out result to git-htmldocs and + git-manpages repositories. + - Handle the remaining patches: - Anything unobvious that is applicable to 'master' (in other @@ -179,12 +274,12 @@ by doing the following: The initial round is done with: $ git checkout ai/topic ;# or "git checkout -b ai/topic master" - $ git am -sc3 mailbox + $ git am -sc3 --whitespace=warn mailbox and replacing an existing topic with subsequent round is done with: $ git checkout master...ai/topic ;# try to reapply to the same base - $ git am -sc3 mailbox + $ git am -sc3 --whitespace=warn mailbox to prepare the new round on a detached HEAD, and then @@ -209,39 +304,59 @@ by doing the following: (trivial typofixes etc. are often squashed directly into the patches that need fixing, without being applied as a separate "SQUASH???" commit), so that they can be removed easily as needed. + The expectation is that the original author will make corrections + in a reroll. + - By now, new topic branches are created and existing topic + branches are updated. The integration branches 'next', 'jch', + and 'seen' need to be updated to contain them. - - Merge maint to master as needed: + - If there are topics that have been merged to 'master' and should + be merged to 'maint', merge them to 'maint', and update the + release notes to the next maintenance release. - $ git checkout master - $ git merge maint - $ make test + - Review the latest issue of "What's cooking" again. Are topics + that have been sufficiently long in 'next' ready to be merged to + 'master'? Are topics we saw earlier and are in 'seen' now got + positive reviews and are ready to be merged to 'next'? - - Merge master to next as needed: + - If there are topics that have been cooking in 'next' long enough + and should be merged to 'master', merge them to 'master', and + update the release notes to the next feature release. - $ git checkout next - $ git merge master - $ make test + - If there were patches directly made on 'maint', merge 'maint' to + 'master'; make sure that the result is what you want. - - Review the last issue of "What's cooking" again and see if topics - that are ready to be merged to 'next' are still in good shape - (e.g. has there any new issue identified on the list with the - series?) + $ git checkout master + $ git merge -m "Sync with 'maint'" --no-log maint + $ git log -p --first-parent ORIG_HEAD.. + $ make test - - Prepare 'jch' branch, which is used to represent somewhere - between 'master' and 'seen' and often is slightly ahead of 'next'. + - Prepare to update the 'jch' branch, which is used to represent + somewhere between 'master' and 'seen' and often is slightly ahead + of 'next', and the 'seen' branch, which is used to hold the rest. $ Meta/Reintegrate master..jch >Meta/redo-jch.sh The result is a script that lists topics to be merged in order to - rebuild 'seen' as the input to Meta/Reintegrate script. Remove - later topics that should not be in 'jch' yet. Add a line that - consists of '### match next' before the name of the first topic - in the output that should be in 'jch' but not in 'next' yet. + rebuild the current 'jch'. Do the same for 'seen'. + + - Review the Meta/redo-jch.sh and Meta/redo-seen.sh scripts. The + former should have a line '### match next'---the idea is that + merging the topics listed before the line on top of 'master' + should result in a tree identical to that of 'next'. - - Now we are ready to start merging topics to 'next'. For each - branch whose tip is not merged to 'next', one of three things can - happen: + - As newly created topics are usually merged near the tip of + 'seen', add them to the end of the Meta/redo-seen.sh script. + Among the topics that were in 'seen', there may be ones that + are not quite ready for 'next' but are getting there. Move + them from Meta/redo-seen.sh to the end of Meta/redo-jch.sh. + The expectation is that you'd use 'jch' as your daily driver + as the first guinea pig, so you should choose carefully. + + - Now we are ready to start rebuilding 'jch' and merging topics to + 'next'. For each branch whose tip is not merged to 'next', one + of three things can happen: - The commits are all next-worthy; merge the topic to next; - The new parts are of mixed quality, but earlier ones are @@ -252,10 +367,12 @@ by doing the following: If a topic that was already in 'next' gained a patch, the script would list it as "ai/topic~1". To include the new patch to the updated 'next', drop the "~1" part; to keep it excluded, do not - touch the line. If a topic that was not in 'next' should be - merged to 'next', add it at the end of the list. Then: + touch the line. + + If a topic that was not in 'next' should be merged to 'next', add + it before the '### match next' line. Then: - $ git checkout -B jch master + $ git checkout --detach master $ sh Meta/redo-jch.sh -c1 to rebuild the 'jch' branch from scratch. "-c1" tells the script @@ -267,26 +384,29 @@ by doing the following: reference to the variable under its old name), in which case prepare an appropriate merge-fix first (see appendix), and rebuild the 'jch' branch from scratch, starting at the tip of - 'master'. + 'master', this time without using "-c1" to merge all topics. - Then do the same to 'next' + Then do the same to 'next'. $ git checkout next $ sh Meta/redo-jch.sh -c1 -e The "-e" option allows the merge message that comes from the history of the topic and the comments in the "What's cooking" to - be edited. The resulting tree should match 'jch' as the same set - of topics are merged on 'master'; otherwise there is a mismerge. - Investigate why and do not proceed until the mismerge is found - and rectified. + be edited. The resulting tree should match 'jch^{/^### match next'}' + as the same set of topics are merged on 'master'; otherwise there + is a mismerge. Investigate why and do not proceed until the mismerge + is found and rectified. + + If 'master' was updated before you started redoing 'next', then - $ git diff jch next + $ git diff 'jch^{/^### match next}' next - Then build the rest of 'jch': + would show differences that went into 'master' (which 'jch' has, + but 'next' does not yet---often it is updates to the release + notes). Merge 'master' back to 'next' if that is the case. - $ git checkout jch - $ sh Meta/redo-jch.sh + $ git merge -m "Sync with 'master'" --no-log master When all is well, clean up the redo-jch.sh script with @@ -296,12 +416,7 @@ by doing the following: merged to 'master'. This may lose '### match next' marker; add it again to the appropriate place when it happens. - - Rebuild 'seen'. - - $ Meta/Reintegrate jch..seen >Meta/redo-seen.sh - - Edit the result by adding new topics that are not still in 'seen' - in the script. Then + - Rebuild 'seen' on top of 'jch'. $ git checkout -B seen jch $ sh Meta/redo-seen.sh @@ -312,7 +427,7 @@ by doing the following: Double check by running - $ git branch --no-merged seen + $ git branch --no-merged seen '??/*' to see there is no unexpected leftover topics. @@ -411,13 +526,13 @@ Preparing a "merge-fix" A merge of two topics may not textually conflict but still have conflict at the semantic level. A classic example is for one topic -to rename an variable and all its uses, while another topic adds a +to rename a variable and all its uses, while another topic adds a new use of the variable under its old name. When these two topics are merged together, the reference to the variable newly added by the latter topic will still use the old name in the result. The Meta/Reintegrate script that is used by redo-jch and redo-seen -scripts implements a crude but usable way to work this issue around. +scripts implements a crude but usable way to work around this issue. When the script merges branch $X, it checks if "refs/merge-fix/$X" exists, and if so, the effect of it is squashed into the result of the mechanical merge. In other words, |