don't use pull_requests object (is empty for external forks)

.github/workflows/comment-download-link.yml

@@ -15,34 +15,39 @@ permissions:
 
 jobs:
   comment-on-pr:
-    if: github.event.workflow_run.conclusion == 'success' && github.event.workflow_run.pull_requests[0] != null
+    if: github.event.workflow_run.conclusion == 'success'
     runs-on: ubuntu-latest
     steps:
 
       - name: Post url to artifact
-        timeout-minutes: 5
         env:
           GITHUB_TOKEN: ${{ github.token }}
           OWNER: ${{ github.repository_owner }}
           REPO: ${{ github.event.repository.name }}
+          CURRENT_JOB_ID: ${{ github.run_id }}
           PREVIOUS_JOB_ID: ${{ github.event.workflow_run.id }}
           PREVIOUS_SUITE_ID: ${{ github.event.workflow_run.check_suite_id }}
-          PR_NUMBER: ${{ github.event.workflow_run.pull_requests[0].number }}
         run: |
 
-          # get artifact id
-          while true; do
-            ARTIFACT_ID=$(gh api "/repos/$OWNER/$REPO/actions/runs/$PREVIOUS_JOB_ID/artifacts" --jq ".artifacts[0].id")
-            if [ -n "$ARTIFACT_ID" ]; then break; fi
-            # the artifact isn't available immediately, retry
-            echo No artifact, will retry shortly
-            sleep 10
-          done
+          # get artifacts
+          read PR_NUMBER ARTIFACT_ID EXPIRES_AT <<< $(gh api "/repos/$OWNER/$REPO/actions/runs/$PREVIOUS_JOB_ID/artifacts" --jq '"\(.artifacts[0].name) \(.artifacts[1].id) \(.artifacts[1].expires_at)"')
+          if [ "$ARTIFACT_ID" == "null" ]; then
+            echo "No artifacts, (probably) not a PR, exiting"
+            exit
+          fi
+          echo "PR NUMBER: $PR_NUMBER"
           echo "ARTIFACT ID: $ARTIFACT_ID"
+          echo "EXPIRES_AT: $EXPIRES_AT"
 
           # post link comment
           gh api "/repos/$OWNER/$REPO/issues/$PR_NUMBER/comments" -F body=@- <<EOF
-          [Download testing apk](https://github.com/$OWNER/$REPO/suites/$PREVIOUS_SUITE_ID/artifacts/$ARTIFACT_ID)
+          | [Download testing apk](https://github.com/$OWNER/$REPO/suites/$PREVIOUS_SUITE_ID/artifacts/$ARTIFACT_ID) |
+          | - |
+          
           This unsigned apk can be installed alongside the original app and should only be used for testing the changes, not for normal usage.
-          The link may expire in 90 days.
+          The link will expire at $EXPIRES_AT.
+          
+          <hr>
+          
+          <sub>This is an automatic comment created by a [Github Action](https://github.com/$OWNER/$REPO/actions/runs/$CURRENT_JOB_ID)</sub>
           EOF

.github/workflows/validate-gradle-build-test.yml

@@ -49,7 +49,6 @@ jobs:
         uses: gradle/gradle-build-action@v2
         with:
           arguments: >
-            build
             assemble${{ env.VARIANT }}
 
       - name: Upload apk as artifact
@@ -58,3 +57,10 @@ jobs:
         with:
           path: ./app/build/outputs/apk/${{ env.VARIANT }}/app-${{ env.VARIANT }}.apk
           name: ${{ env.NAME }}
+
+      - name: Upload PR id as artifact
+        if: ${{ github.event_name == 'pull_request' }}
+        uses: actions/upload-artifact@v3
+        with:
+          path: /dev/null
+          name: ${{ github.event.number }}