fix: bug retrieving diff when persist credentials is false (#1209)

Co-authored-by: GitHub Action <action@github.com>

.github/workflows/test.yml

@@ -343,6 +343,39 @@ jobs:
         shell:
           bash
 
+  test-pull-request-without-persist-credentials:
+    name: Test changed-files with pull request without persist credentials
+    runs-on: ubuntu-latest
+    needs: build
+    if: github.event_name != 'push'
+    strategy:
+      fail-fast: false
+      max-parallel: 4
+      matrix:
+        fetch-depth: [1, 2, 0]
+
+    steps:
+      - name: Checkout to branch
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: ${{ matrix.fetch-depth }}
+          persist-credentials: false
+
+      - name: Download build assets
+        uses: actions/download-artifact@v3
+        with:
+          name: build-assets
+
+      - name: Run changed-files
+        id: changed-files
+        uses: ./
+
+      - name: Show output
+        run: |
+          echo '${{ toJSON(steps.changed-files.outputs) }}'
+        shell:
+          bash
+
   test-non-existent-base-sha:
     name: Test changed-files non existent base sha
     runs-on: ubuntu-latest