contributing: add guidelines for including changelogs

Recently there were several contributors that included their changelog
in the commit message and/or didn't include a changelog at all. Add
comprehensive guidelines to help people figuring the email-based review
workflow.

Signed-off-by: Robin Jarry <robin@jarry.cc>

2 files changed, 24 insertions, 0 deletions

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 340eef83..fd01f81c 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -65,6 +65,9 @@ defaults:
     $ make gitconfig
     git config format.subjectPrefix "PATCH aerc"
     git config sendemail.to "~rjarry/aerc-devel@lists.sr.ht"
+    git config format.notes true
+    git config notes.rewriteRef refs/notes/commits
+    git config notes.rewriteMode concatenate
     '.git/hooks/sendemail-validate' -> '../../contrib/sendemail-validate'
 
 And send the patch to the mailing list ([step-by-step
@@ -101,6 +104,24 @@ Then you should send a v2 (and maybe a v3, v4, etc.):
 Be polite, patient and address *all* of the reviewers' remarks. If you disagree
 with something, feel free to discuss it.
 
+To help reviewers track what changed between respins of your patch, it is nice
+to include a mini change log **after** the `---` line that separates your
+commit message from the diff. You can either do that manually when reviewing
+(`git send-email --annotate`) before sending your email, or you can use [git
+notes][git-notes] to make this part of your git workflow:
+
+    $ git notes edit $ref
+
+[git-notes]: https://git-scm.com/docs/git-notes
+
+When `format.notes = true` is set in your git configuration, notes attached to
+commits will automatically be included in the correct location by `git
+format-patch` and `git send-email`.
+
+If you have set `notes.rewriteMode = concatenante`, squashing commits together
+with `git rebase -i` will also merge their respective notes by concatenating
+them.
+
 Once your patch has been reviewed and approved (and if the maintainer is OK
 with it), it will be applied and pushed.
 
diff --git a/GNUmakefile b/GNUmakefile
index e8ac67fe..3a5a719f 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -119,6 +119,9 @@ uninstall:
 gitconfig:
 	git config format.subjectPrefix "PATCH aerc"
 	git config sendemail.to "~rjarry/aerc-devel@lists.sr.ht"
+	git config format.notes true
+	git config notes.rewriteRef refs/notes/commits
+	git config notes.rewriteMode concatenate
 	@mkdir -p .git/hooks
 	@rm -f .git/hooks/sendemail-validate*
 	@if grep -q GIT_SENDEMAIL_FILE_COUNTER `git --exec-path`/git-send-email 2>/dev/null; then \