restore old behavior when pushing to target branch directly

.gitlab-ci.yml

@@ -30,7 +30,11 @@ check_style:
     - export EASYBUILD_MODULE_NAMING_SCHEME="FlexibleCustomHierarchicalMNS"
     - faulty=""
     - export TIP_COMMIT=$CI_COMMIT_SHA
+    - if [ "x$CI_COMMIT_BRANCH" = "x$TARGET_BRANCH" ]; then
+    - export BASE_COMMIT=$CI_COMMIT_BEFORE_SHA
+    - else
     - export BASE_COMMIT=$(git merge-base "$TIP_COMMIT" "origin/$TARGET_BRANCH")
+    - fi
     - printf "Checking changes between base %s (%s) and tip %s (%s)\n" "$BASE_COMMIT" "$(git describe --all --exclude pipeline/* $BASE_COMMIT 2> /dev/null)" "$TIP_COMMIT" "$(git describe --all --exclude pipeline/* $TIP_COMMIT 2> /dev/null)"
     - eb_list=$(git diff-tree --no-commit-id -r "$BASE_COMMIT" "$TIP_COMMIT" | awk '$5 ~ /^M|^A/ && $6 ~ /eb$/ {print($6)}')
     - echo "List of files to be checked $eb_list"