changelog: get unreleased entries from commit trailers

Asking contributors to update the CHANGELOG.md file is causing lots of
merge conflicts. Introduce a new workflow where contributors can attach
changelog entries in patches via git trailers.

Changelog-added: For new features.
Changelog-fixed: For bug fixes.
Changelog-changed: For behaviour or config format changes.
Changelog-deprecated: For deprecation or removal of functionality.

If a complete trailer is longer than 72 characters, it can be continued
by indenting extra lines with a single space. The trailer text must be
valid markdown.

Update CONTRIBUTING.md with new guidelines.

Update contrib/release.sh to extract these trailers before tagging and
create a new section in CHANGELOG.md.

Extract unreleased entries in this commit to follow the new workflow.

Changelog-added: New `flagged` criteria for `:sort`.
Changelog-added: New `:send-keys` command to control embedded terminals.
Changelog-added: Account aliases now support fnmatch-style wildcards.
Changelog-fixed: `colorize` support for wildcards `?` and `*`.
Signed-off-by: Robin Jarry <robin@jarry.cc>
Acked-by: Moritz Poldrack <moritz@poldrack.dev>

1 files changed, 19 insertions, 1 deletions

diff --git a/contrib/release.sh b/contrib/release.sh
index e3b3369c..001c68d2 100755
--- a/contrib/release.sh
+++ b/contrib/release.sh
@@ -13,7 +13,25 @@ tag_url="https://git.sr.ht/~rjarry/aerc/refs/$next_tag"
 
 echo "======= Creating release commit..."
 sed -i GNUmakefile -e "s/$prev_tag/$next_tag/g"
-sed -i CHANGELOG.md -e "s|^## \[Unreleased\].*|&\n\n## [$next_tag]($tag_url) - $(date +%Y-%m-%d)|"
+make wrap
+{
+	echo
+	echo "## [$next_tag]($tag_url) - $(date +%Y-%m-%d)"
+	for kind in Added Fixed Changed Deprecated; do
+		format="%(trailers:key=Changelog-$kind,unfold,valueonly)"
+		if git log --format="$format" $prev_tag.. | grep -q .; then
+			echo
+			echo "### $kind"
+			echo
+			git log --format="$format" $prev_tag.. | \
+				sed '/^$/d; s/[[:space:]]\+/ /; s/^/- /' | \
+				./wrap -r
+		fi
+	done
+} > .changelog.md
+sed -i CHANGELOG.md -e '/^The format is based on/ r .changelog.md'
+${EDITOR:-vi} CHANGELOG.md
+rm -f .changelog.md
 git add GNUmakefile CHANGELOG.md
 git commit -sm "Release version $next_tag"