Part of the maintainer's job is to keep up-to-date and publish the 'amlog' which stores a mapping between a patch's 'Message-Id' e-mail header and the commit generated by applying said patch. But our Documentation/howto/maintain-git.txt does not mention the amlog, or the scripts which exist to help the maintainer keep the amlog up-to-date. (This bit me during the first integration round I did as interim maintainer[1] involved a lot of manual clean-up. More recently it has come up as part of a research effort to better understand a patch's lifecycle on the list[2].) Address this gap by briefly documenting the existence and purpose of the 'post-applypatch' hook in maintaining the amlog entries. [1]: https://lore.kernel.org/git/Y19dnb2M+yObnftj@nand.local/ [2]: https://lore.kernel.org/git/CAJoAoZ=4ARuH3aHGe5yC_Xcnou_c396q_ZienYPY7YnEzZcyEg@xxxxxxxxxxxxxx/ Suggested-by: Junio C Hamano <gitster@xxxxxxxxx> Helped-by: Junio C Hamano <gitster@xxxxxxxxx> Signed-off-by: Taylor Blau <me@xxxxxxxxxxxx> --- Documentation/howto/maintain-git.txt | 44 ++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) diff --git a/Documentation/howto/maintain-git.txt b/Documentation/howto/maintain-git.txt index da31332f113..f52f32eda93 100644 --- a/Documentation/howto/maintain-git.txt +++ b/Documentation/howto/maintain-git.txt @@ -122,6 +122,13 @@ 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 ----------------- @@ -165,6 +172,43 @@ 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/notes/next:refs/notes/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 Range-diff against v2: 1: 5cc8e2bcb88 ! 1: 88a13b9f2b6 Documentation: mention the amlog in howto/maintain-git.txt @@ Documentation/howto/maintain-git.txt: by doing the following: In practice, almost no patch directly goes to 'master' or 'maint'. -+ The maintainer is expected to update refs/notes/amlog with a -+ mapping between the applied commit and the 'Message-Id' -+ corresponding to the e-mail which carried the patch. ++ 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 created 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: ++ 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 + -+ (note that this configuration is not read by 'cherry-pick'). ++ 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. + -+ Finally, take care that the amlog entries are pushed out during -+ integration cycles since external tools and contributors (in -+ addition to internal scripts) may rely on them. ++ 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/notes/next:refs/notes/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 base-commit: 3857aae53f3633b7de63ad640737c657387ae0c6 -- 2.47.0.rc0.8.g9a975e77790
