fix(ci): test script not working on fork

Author: nbrugger-tgm

.github/workflows/test_action.yml

@@ -10,11 +10,12 @@ jobs:
     steps:
       - uses: actions/checkout@v2
         with:
+          ref: ${{ github.head_ref }}
           fetch-depth: 0  # ensures that tags are fetched, seems to be needed
       - name: Capture commit id
         id: capture
         run: |
-          COMMIT_ID=$(git rev-parse origin/${{ github.head_ref }})
+          COMMIT_ID=$(git rev-parse ${{ github.head_ref }})
           echo "The sha of the starting commit is $COMMIT_ID"
           echo "::set-output name=commit::$COMMIT_ID"
       - name: create test commit
@@ -32,7 +33,7 @@ jobs:
           push: false
       - name: Test push
         run: |
-          last_pushed_commit=$(git rev-parse origin/${{ github.head_ref }})
+          last_pushed_commit=$(git rev-parse ${{ github.head_ref }})
           echo "Commit sha on origin : $last_pushed_commit"
           if [[ $last_pushed_commit != ${{steps.capture.outputs.commit}} ]]; then
             echo "Something got pushed to ${{ github.head_ref }}"