[PATCH] Documentation: mention the amlog in howto/maintain-git.txt

[Taylor Blau <me@ttaylorr.com>]

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@mail.gmail.com/

Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
---
 Documentation/howto/maintain-git.txt | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/Documentation/howto/maintain-git.txt b/Documentation/howto/maintain-git.txt
index da31332f11..fd1560327c 100644
--- a/Documentation/howto/maintain-git.txt
+++ b/Documentation/howto/maintain-git.txt
@@ -165,6 +165,22 @@ 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.
+
+   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:
+
+      [notes]
+	rewriteref = refs/notes/amlog
+
+   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.
+
  - 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

base-commit: 3857aae53f3633b7de63ad640737c657387ae0c6
-- 
2.46.2.633.gf09c3c1769.dirty