ci: push tags and skip unnecessary rebases in sync workflow (#9)

* ci: push merged lightweight tags in sync workflow

Since `--follow-tags` only pushes annotated tags, we need to separately
list merged tags and push them by name.

Signed-off-by: Daniel Hast <hast.daniel@protonmail.com>

* ci: skip unnecessary rebases in sync workflow

If the commit we would rebase to is already present on the working
branch, we skip the rebase since that means we wouldn't be pushing any
new commits.

---------

Signed-off-by: Daniel Hast <hast.daniel@protonmail.com>

Author: HastD

.github/workflows/upstream-sync.yml

@@ -46,5 +46,19 @@ jobs:
 
           spec_url="https://src.fedoraproject.org/rpms/selinux-policy/raw/f${FEDORA_VERSION}/f/selinux-policy.spec"
           stable_commit=$(curl -Ls "${spec_url}" | grep -E '^%global commit [0-9a-fA-F]+$')
-          git rebase "${stable_commit#%global commit }"
-          git push --follow-tags --force-with-lease
+          stable_commit="${stable_commit#%global commit }"
+          set +e
+          git merge-base --is-ancestor "${stable_commit}" HEAD
+          status=$?
+          set -e
+          case "${status}" in
+          0) ;;
+          1)
+            git rebase "${stable_commit}"
+            git push --follow-tags --force-with-lease
+            ;;
+          *) exit "${status}" ;;
+          esac
+
+          readarray -t merged_tags < <(git tag -l "v${FEDORA_VERSION}.*" --merged)
+          git push origin "${merged_tags[@]}"