create-replacement-pr: improve behaviour without autosquash

When we don't need to autosquash a PR, we can reuse the previously built
bottles without destroying status check information, so let's do that to
minimise the number of times we have to re-run CI.

.github/workflows/create-replacement-pr.yml

@@ -19,7 +19,7 @@ on:
       upload:
         description: >
           Upload bottles built from original pull request? (default: false)
-          Warning: This destroys status check information!
+          Warning: This destroys status check information when used with autosquash!
         type: boolean
         required: false
         default: false
@@ -72,23 +72,6 @@ jobs:
         with:
           test-bot: false
 
-      - name: Configure Git user
-        id: git-user-config
-        uses: Homebrew/actions/git-user-config@master
-        with:
-          username: BrewTestBot
-
-      - name: Checkout replacement PR branch
-        working-directory: ${{ steps.set-up-homebrew.outputs.repository-path }}
-        run: |
-          if git ls-remote --exit-code --heads origin "$REPLACEMENT_BRANCH"
-          then
-            echo "::error ::Branch $REPLACEMENT_BRANCH already exists!"
-            exit 1
-          fi
-
-          git checkout -b "$REPLACEMENT_BRANCH" origin/master
-
       - name: Get reviewers
         id: reviewers
         env:
@@ -107,6 +90,37 @@ jobs:
           echo "reviewers=$reviewers" >> "$GITHUB_OUTPUT"
           echo "approved=$approved" >> "$GITHUB_OUTPUT"
 
+      - name: Check approval if needed
+        if: inputs.upload && !fromJson(steps.reviewers.outputs.approved)
+        run: |
+          echo "::error ::Refusing to upload bottles because PR #$PR is not approved!"
+          exit 1
+
+      - name: Configure Git user
+        id: git-user-config
+        uses: Homebrew/actions/git-user-config@master
+        with:
+          username: BrewTestBot
+
+      - name: Checkout PR branch
+        if: ${{ !inputs.autosquash }}
+        working-directory: ${{steps.set-up-homebrew.outputs.repository-path}}
+        env:
+          GH_TOKEN: ${{secrets.GITHUB_TOKEN}}
+        run: gh pr checkout "$PR"
+
+      - name: Checkout replacement PR branch
+        working-directory: ${{ steps.set-up-homebrew.outputs.repository-path }}
+        env:
+          START_POINT: ${{ inputs.autosquash && 'origin/master' || 'HEAD' }}
+        run: |
+          if git ls-remote --exit-code --heads origin "$REPLACEMENT_BRANCH"
+          then
+            echo "::error ::Branch $REPLACEMENT_BRANCH already exists!"
+            exit 1
+          fi
+          git checkout -b "$REPLACEMENT_BRANCH" "$START_POINT"
+
       - name: Dismiss approvals
         if: fromJson(steps.reviewers.outputs.approved)
         uses: Homebrew/actions/dismiss-approvals@master
@@ -137,7 +151,7 @@ jobs:
             --workflows=tests.yml \
             --committer="$BREWTESTBOT_NAME_EMAIL" \
             --root-url="https://ghcr.io/v2/homebrew/core" \
-            "${{ inputs.autosquash && '--autosquash' || '--clean' }}" \
+            ${{ inputs.autosquash && '--autosquash' || '--clean --no-cherry-pick' }} \
             ${{ inputs.upload && '' || '--no-upload' }} \
             ${{ inputs.warn_on_upload_failure && '--warn-on-upload-failure' || '' }} \
             ${{ inputs.message && '--message="$MESSAGE"' || '' }} \

.github/workflows/publish-commit-bottles.yml

@@ -191,7 +191,7 @@ jobs:
             --ref "$GITHUB_REF_NAME" \
             --field pull_request="$PR" \
             --field autosquash="$AUTOSQUASH" \
-            --field upload=false \
+            --field upload='${{ !inputs.autosquash }}' \
             --field warn_on_upload_failure=false \
             --field message="$MESSAGE"