ci: fix release-notes for tag builds

scripts/generate-release-notes.sh

@@ -11,7 +11,13 @@ if [ -z "$CURRENT_TAG" ]; then
     exit 1
 fi
 
-PREVIOUS_TAG=$(git describe --tags --abbrev=0 "$CURRENT_TAG"^ 2>/dev/null || echo "")
+# In CI, the tag name may be available but not present as a local ref.
+CURRENT_REF="$CURRENT_TAG"
+if ! git rev-parse --verify -q "${CURRENT_REF}^{commit}" >/dev/null; then
+    CURRENT_REF="${DRONE_COMMIT:-HEAD}"
+fi
+
+PREVIOUS_TAG=$(git describe --tags --abbrev=0 "${CURRENT_REF}^" 2>/dev/null || echo "")
 
 mkdir -p "$(dirname "$OUTPUT_FILE")"
 
@@ -23,7 +29,7 @@ mkdir -p "$(dirname "$OUTPUT_FILE")"
         echo "Changes since $PREVIOUS_TAG:"
         echo
 
-        git log "$PREVIOUS_TAG..$CURRENT_TAG" --pretty=format:"%s" | while read -r commit; do
+        git log "$PREVIOUS_TAG..$CURRENT_REF" --pretty=format:"%s" | while read -r commit; do
             if [[ $commit =~ ^([a-z]+)(\(.+\))?:\ (.+)$ ]]; then
                 TYPE="${BASH_REMATCH[1]}"
                 SCOPE="${BASH_REMATCH[2]}"
@@ -54,7 +60,7 @@ mkdir -p "$(dirname "$OUTPUT_FILE")"
     else
         echo "Initial release"
         echo
-        git log "$CURRENT_TAG" --pretty=format:"- %s" | head -20
+        git log "$CURRENT_REF" --pretty=format:"- %s" | head -20
     fi
 
     echo