ci: add latest-changelog.awk

Author: jpgrayson

.github/workflows/ci.yml

@@ -286,10 +286,14 @@ jobs:
       - name: Make source archive
         run: |
           ./contrib/release/make-archive.sh artifacts
+      - name: Latest Changes
+        run: |
+          ./contrib/release/latest-changelog.awk CHANGELOG.md >latest-changes.md
       - name: Draft Release
         uses: softprops/action-gh-release@v1
         with:
           draft: true
+          body_path: latest-changes.md
           fail_on_unmatched_files: true
           files: |
             artifacts/stgit-*.tar.gz

contrib/release/latest-changelog.awk

@@ -0,0 +1,30 @@
+#!/usr/bin/env -S awk -f
+
+# Extract the latest release notes from CHANGELOG.md.
+#
+# The h3 sections from the first h2 section are printed.
+
+BEGIN {
+    foundFirstH2 = 0
+    foundFirstH3 = 0
+    foundSecondH2 = 0
+}
+
+{
+    if (!foundFirstH2) {
+        if ($0 ~ /^## /) {
+            foundFirstH2 = 1
+        }
+    } else if (!foundFirstH3) {
+        if ($0 ~ /^### /) {
+            foundFirstH3 = 1
+            print $0
+        }
+    } else if (!foundSecondH2) {
+        if ($0 ~ /^## /) {
+            foundSecondH2 = 1
+        } else {
+            print $0
+        }
+    }
+}