Merge 1d3fa26c9e into 85e6279cec

* Update README.md

* Update README.md

Co-authored-by: Josh Gross <joshmgross@github.com>

---------

Co-authored-by: Josh Gross <joshmgross@github.com>

README.md

@@ -143,6 +143,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 - [Checkout pull request HEAD commit instead of merge commit](#Checkout-pull-request-HEAD-commit-instead-of-merge-commit)
 - [Checkout pull request on closed event](#Checkout-pull-request-on-closed-event)
 - [Push a commit using the built-in token](#Push-a-commit-using-the-built-in-token)
+- [Push a commit to a PR using the built-in token](#Push-a-commit-to-a-PR-using-the-built-in-token)
 
 ## Fetch only the root files
 
@@ -211,7 +212,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
     repository: my-org/my-tools
     path: my-tools
 ```
-> - If your secondary repository is private you will need to add the option noted in [Checkout multiple repos (private)](#Checkout-multiple-repos-private)
+> - If your secondary repository is private or internal you will need to add the option noted in [Checkout multiple repos (private)](#Checkout-multiple-repos-private)
 
 ## Checkout multiple repos (nested)
 
@@ -225,7 +226,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
     repository: my-org/my-tools
     path: my-tools
 ```
-> - If your secondary repository is private you will need to add the option noted in [Checkout multiple repos (private)](#Checkout-multiple-repos-private)
+> - If your secondary repository is private or internal you will need to add the option noted in [Checkout multiple repos (private)](#Checkout-multiple-repos-private)
 
 ## Checkout multiple repos (private)
 
@@ -288,6 +289,40 @@ jobs:
 ```
 *NOTE:* The user email is `{user.id}+{user.login}@users.noreply.github.com`. See users API: https://api.github.com/users/github-actions%5Bbot%5D
 
+## Push a commit to a PR using the built-in token
+
+In a pull request trigger, `ref` is required as GitHub Actions checks out in detached HEAD mode, meaning it doesn’t check out your branch by default.
+
+```yaml
+on: pull_request
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.head_ref }}
+      - run: |
+          date > generated.txt
+          # Note: the following account information will not work on GHES
+          git config user.name "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+          git add .
+          git commit -m "generated"
+          git push
+```
+
+*NOTE:* The user email is `{user.id}+{user.login}@users.noreply.github.com`. See users API: https://api.github.com/users/github-actions%5Bbot%5D
+
+# Recommended permissions
+
+When using the `checkout` action in your GitHub Actions workflow, it is recommended to set the following `GITHUB_TOKEN` permissions to ensure proper functionality, unless alternative auth is provided via the `token` or `ssh-key` inputs:
+
+```yaml
+permissions:
+  contents: read
+```
+
 # License
 
 The scripts and documentation in this project are released under the [MIT License](LICENSE)

dist/index.js

@@ -2114,7 +2114,8 @@ function testRef(git, ref, commit) {
         // refs/tags/
         else if (upperRef.startsWith('REFS/TAGS/')) {
             const tagName = ref.substring('refs/tags/'.length);
-            return ((yield git.tagExists(tagName)) && commit === (yield git.revParse(ref)));
+            return ((yield git.tagExists(tagName)) &&
+                commit === (yield git.revParse(`${ref}^{commit}`)));
         }
         // Unexpected
         else {

src/ref-helper.ts

@@ -171,7 +171,8 @@ export async function testRef(
   else if (upperRef.startsWith('REFS/TAGS/')) {
     const tagName = ref.substring('refs/tags/'.length)
     return (
-      (await git.tagExists(tagName)) && commit === (await git.revParse(ref))
+      (await git.tagExists(tagName)) &&
+      commit === (await git.revParse(`${ref}^{commit}`))
     )
   }
   // Unexpected