Add branch option to checkout on push

.github/workflows/cygwin.yml

@@ -44,10 +44,10 @@ jobs:
       # Not using official actions/checkout because it's unstable and sometimes doesn't work for a fork.
       - name: Checkout ruby
         run: |
-          git clone --single-branch --shallow-since=yesterday https://github.com/${{ github.repository }} src
+          git clone --single-branch --shallow-since=yesterday --branch=${GITHUB_REF#refs/heads/} https://github.com/${{ github.repository }} src
           git -C src reset --hard ${{ github.sha }}
         if: github.event_name == 'push'
-        shell: cmd
+        shell: bash
       - name: Checkout a pull request
         run: |
           git clone --single-branch --shallow-since=yesterday --branch=${{ github.event.pull_request.head.ref }} https://github.com/${{ github.event.pull_request.head.repo.full_name }} src

.github/workflows/macos.yml

@@ -22,7 +22,7 @@ jobs:
       # Not using official actions/checkout because it's unstable and sometimes doesn't work for a fork.
       - name: Checkout ruby
         run: |
-          git clone --single-branch --shallow-since=yesterday https://github.com/${{ github.repository }} src
+          git clone --single-branch --shallow-since=yesterday --branch=${GITHUB_REF#refs/heads/} https://github.com/${{ github.repository }} src
           git -C src reset --hard "$GITHUB_SHA"
         if: github.event_name == 'push'
       - name: Checkout a pull request

.github/workflows/mingw.yml

@@ -39,9 +39,10 @@ jobs:
       # Not using official actions/checkout@v2 because it's unstable.
       - name: Checkout ruby
         run: |
-          git clone --single-branch --shallow-since=yesterday https://github.com/${{ github.repository }} src
+          git clone --single-branch --shallow-since=yesterday --branch=${GITHUB_REF#refs/heads/} https://github.com/${{ github.repository }} src
           git -C src reset --hard "$GITHUB_SHA"
         if: github.event_name == 'push'
+        shell: bash
       - name: Checkout a pull request
         run: |
           git clone --single-branch --shallow-since=yesterday --branch=${{ github.event.pull_request.head.ref }} https://github.com/${{ github.event.pull_request.head.repo.full_name }} src

.github/workflows/mjit.yml

@@ -24,7 +24,7 @@ jobs:
       # Not using official actions/checkout because it's unstable and sometimes doesn't work for a fork.
       - name: Checkout ruby
         run: |
-          git clone --single-branch --shallow-since=yesterday https://github.com/${{ github.repository }} src
+          git clone --single-branch --shallow-since=yesterday --branch=${GITHUB_REF#refs/heads/} https://github.com/${{ github.repository }} src
           git -C src reset --hard "$GITHUB_SHA"
         if: github.event_name == 'push'
       - name: Checkout a pull request

.github/workflows/ubuntu.yml

@@ -55,7 +55,7 @@ jobs:
       # Not using official actions/checkout because it's unstable and sometimes doesn't work for a fork.
       - name: Checkout ruby
         run: |
-          git clone --single-branch --shallow-since=yesterday https://github.com/${{ github.repository }} src
+          git clone --single-branch --shallow-since=yesterday --branch=${GITHUB_REF#refs/heads/} https://github.com/${{ github.repository }} src
           git -C src reset --hard "$GITHUB_SHA"
         if: github.event_name == 'push'
       - name: Checkout a pull request

.github/workflows/windows.yml

@@ -40,9 +40,10 @@ jobs:
       # Not using official actions/checkout because it's unstable and sometimes doesn't work for a fork.
       - name: Checkout ruby
         run: |
-          git clone --single-branch --shallow-since=yesterday https://github.com/${{ github.repository }} src
+          git clone --single-branch --shallow-since=yesterday --branch=${GITHUB_REF#refs/heads/} https://github.com/${{ github.repository }} src
           git -C src reset --hard ${{ github.sha }}
         if: github.event_name == 'push'
+        shell: bash
       - name: Checkout a pull request
         run: |
           git clone --single-branch --shallow-since=yesterday --branch=${{ github.event.pull_request.head.ref }} https://github.com/${{ github.event.pull_request.head.repo.full_name }} src