backport fixes to releases-v4 (#2524)

* block checking out fork pr for pull_request_target and workflow_run (#2454)

* block checking out fork pr for some events

* address copilot and reviewer feedback

* run prettier formatting

* build

* update urls

* update readme

* update description and url again

* edit url one more time

* update error wording (#2467)

.github/workflows/check-dist.yml

@@ -24,10 +24,10 @@ jobs:
     steps:
       - uses: actions/checkout@v4.1.6
 
-      - name: Set Node.js 24.x
+      - name: Set Node.js 20.x
         uses: actions/setup-node@v4
         with:
-          node-version: 24.x
+          node-version: 20.x
 
       - name: Install dependencies
         run: npm ci

.github/workflows/test.yml

@@ -18,7 +18,7 @@ jobs:
     steps:
       - uses: actions/setup-node@v4
         with:
-          node-version: 24.x
+          node-version: 20.x
       - uses: actions/checkout@v4.1.6
       - run: npm ci
       - run: npm run build

.github/workflows/update-main-version.yml

@@ -11,7 +11,6 @@ on:
         type: choice
         description: The major version to update
         options:
-          - v5
           - v4
           - v3
           - v2

CHANGELOG.md

@@ -1,9 +1,5 @@
 # Changelog
 
-## V5.0.0
-* Update actions checkout to use node 24 by @salmanmkc in https://github.com/actions/checkout/pull/2226
-
-
 ## V4.3.0
 * docs: update README.md by @motss in https://github.com/actions/checkout/pull/1971
 * Add internal repos for checking out multiple repositories by @mouismail in https://github.com/actions/checkout/pull/1977

README.md

@@ -1,9 +1,5 @@
 [![Build and Test](https://github.com/actions/checkout/actions/workflows/test.yml/badge.svg)](https://github.com/actions/checkout/actions/workflows/test.yml)
 
-# Checkout V5
-
-Checkout v5 now supports Node.js 24
-
 # Checkout V4
 
 This action checks-out your repository under `$GITHUB_WORKSPACE`, so your workflow can access it.
@@ -40,7 +36,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 
 <!-- start usage -->
 ```yaml
-- uses: actions/checkout@v5
+- uses: actions/checkout@v4
   with:
     # Repository name with owner. For example, actions/checkout
     # Default: ${{ github.repository }}
@@ -162,32 +158,24 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 
 # Scenarios
 
-- [Checkout V5](#checkout-v5)
-- [Checkout V4](#checkout-v4)
-    - [Note](#note)
-- [What's new](#whats-new)
-- [Usage](#usage)
-- [Scenarios](#scenarios)
-  - [Fetch only the root files](#fetch-only-the-root-files)
-  - [Fetch only the root files and `.github` and `src` folder](#fetch-only-the-root-files-and-github-and-src-folder)
-  - [Fetch only a single file](#fetch-only-a-single-file)
-  - [Fetch all history for all tags and branches](#fetch-all-history-for-all-tags-and-branches)
-  - [Checkout a different branch](#checkout-a-different-branch)
-  - [Checkout HEAD^](#checkout-head)
-  - [Checkout multiple repos (side by side)](#checkout-multiple-repos-side-by-side)
-  - [Checkout multiple repos (nested)](#checkout-multiple-repos-nested)
-  - [Checkout multiple repos (private)](#checkout-multiple-repos-private)
-  - [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)
-- [Recommended permissions](#recommended-permissions)
-- [License](#license)
+- [Fetch only the root files](#Fetch-only-the-root-files)
+- [Fetch only the root files and `.github` and `src` folder](#Fetch-only-the-root-files-and-github-and-src-folder)
+- [Fetch only a single file](#Fetch-only-a-single-file)
+- [Fetch all history for all tags and branches](#Fetch-all-history-for-all-tags-and-branches)
+- [Checkout a different branch](#Checkout-a-different-branch)
+- [Checkout HEAD^](#Checkout-HEAD)
+- [Checkout multiple repos (side by side)](#Checkout-multiple-repos-side-by-side)
+- [Checkout multiple repos (nested)](#Checkout-multiple-repos-nested)
+- [Checkout multiple repos (private)](#Checkout-multiple-repos-private)
+- [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
 
 ```yaml
-- uses: actions/checkout@v5
+- uses: actions/checkout@v4
   with:
     sparse-checkout: .
 ```
@@ -195,7 +183,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 ## Fetch only the root files and `.github` and `src` folder
 
 ```yaml
-- uses: actions/checkout@v5
+- uses: actions/checkout@v4
   with:
     sparse-checkout: |
       .github
@@ -205,7 +193,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 ## Fetch only a single file
 
 ```yaml
-- uses: actions/checkout@v5
+- uses: actions/checkout@v4
   with:
     sparse-checkout: |
       README.md
@@ -215,7 +203,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 ## Fetch all history for all tags and branches
 
 ```yaml
-- uses: actions/checkout@v5
+- uses: actions/checkout@v4
   with:
     fetch-depth: 0
 ```
@@ -223,7 +211,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 ## Checkout a different branch
 
 ```yaml
-- uses: actions/checkout@v5
+- uses: actions/checkout@v4
   with:
     ref: my-branch
 ```
@@ -231,7 +219,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 ## Checkout HEAD^
 
 ```yaml
-- uses: actions/checkout@v5
+- uses: actions/checkout@v4
   with:
     fetch-depth: 2
 - run: git checkout HEAD^
@@ -241,12 +229,12 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 
 ```yaml
 - name: Checkout
-  uses: actions/checkout@v5
+  uses: actions/checkout@v4
   with:
     path: main
 
 - name: Checkout tools repo
-  uses: actions/checkout@v5
+  uses: actions/checkout@v4
   with:
     repository: my-org/my-tools
     path: my-tools
@@ -257,10 +245,10 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 
 ```yaml
 - name: Checkout
-  uses: actions/checkout@v5
+  uses: actions/checkout@v4
 
 - name: Checkout tools repo
-  uses: actions/checkout@v5
+  uses: actions/checkout@v4
   with:
     repository: my-org/my-tools
     path: my-tools
@@ -271,12 +259,12 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 
 ```yaml
 - name: Checkout
-  uses: actions/checkout@v5
+  uses: actions/checkout@v4
   with:
     path: main
 
 - name: Checkout private tools
-  uses: actions/checkout@v5
+  uses: actions/checkout@v4
   with:
     repository: my-org/my-private-tools
     token: ${{ secrets.GH_PAT }} # `GH_PAT` is a secret that contains your PAT
@@ -289,7 +277,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 ## Checkout pull request HEAD commit instead of merge commit
 
 ```yaml
-- uses: actions/checkout@v5
+- uses: actions/checkout@v4
   with:
     ref: ${{ github.event.pull_request.head.sha }}
 ```
@@ -305,7 +293,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v4
 ```
 
 ## Push a commit using the built-in token
@@ -316,7 +304,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v4
       - run: |
           date > generated.txt
           # Note: the following account information will not work on GHES
@@ -338,7 +326,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v4
         with:
           ref: ${{ github.head_ref }}
       - run: |

__test__/input-helper.test.ts

@@ -12,15 +12,24 @@ const gitHubWorkspace = path.resolve('/checkout-tests/workspace')
 // Inputs for mock @actions/core
 let inputs = {} as any
 
+// Replicate @actions/core getInput behavior: it trims whitespace by default
+// (String.prototype.trim(), which strips characters such as a leading U+FEFF BOM)
+// unless trimWhitespace is explicitly set to false.
+const getInputImpl = (name: string, options?: {trimWhitespace?: boolean}) => {
+  const val = inputs[name] ?? ''
+  if (options && options.trimWhitespace === false) {
+    return val
+  }
+  return typeof val === 'string' ? val.trim() : val
+}
+
 // Shallow clone original @actions/github context
 let originalContext = {...github.context}
 
 describe('input-helper tests', () => {
   beforeAll(() => {
     // Mock getInput
-    jest.spyOn(core, 'getInput').mockImplementation((name: string) => {
-      return inputs[name]
-    })
+    jest.spyOn(core, 'getInput').mockImplementation(getInputImpl as any)
 
     // Mock error/warning/info/debug
     jest.spyOn(core, 'error').mockImplementation(jest.fn())
@@ -141,6 +150,26 @@ describe('input-helper tests', () => {
     expect(settings.commit).toBeFalsy()
   })
 
+  it('does not reclassify a ref as sha when a BOM is prefixed', async () => {
+    // A fork branch named "<U+FEFF>" + 40 hex chars. core.getInput trims the
+    // BOM by default, which previously collapsed this into a bare SHA and
+    // bypassed the unsafe fork PR checkout guard.
+    inputs.ref = '\uFEFF522d932fae5296da51fdf431934425ecf891c6a2'
+    const settings: IGitSourceSettings = await inputHelper.getInputs()
+    expect(settings.commit).toBeFalsy()
+    expect(settings.ref).toBe('522d932fae5296da51fdf431934425ecf891c6a2')
+  })
+
+  it('treats a sha surrounded by ascii whitespace as a commit', async () => {
+    // ASCII whitespace can only come from the workflow author's YAML (git ref
+    // names cannot contain it), so trimming it and treating the value as a
+    // commit is safe.
+    inputs.ref = '  1111111111222222222233333333334444444444  '
+    const settings: IGitSourceSettings = await inputHelper.getInputs()
+    expect(settings.ref).toBeFalsy()
+    expect(settings.commit).toBe('1111111111222222222233333333334444444444')
+  })
+
   it('sets workflow organization ID', async () => {
     const settings: IGitSourceSettings = await inputHelper.getInputs()
     expect(settings.workflowOrganizationId).toBe(123456)
@@ -161,6 +190,7 @@ describe('input-helper tests', () => {
     it('allows the default self-checkout on a fork pull_request_target', async () => {
       const originalEvent = github.context.eventName
       const originalPayload = github.context.payload
+      const originalSha = github.context.sha
       try {
         github.context.eventName = 'pull_request_target'
         github.context.payload = forkPayload as any
@@ -172,6 +202,7 @@ describe('input-helper tests', () => {
       } finally {
         github.context.eventName = originalEvent
         github.context.payload = originalPayload
+        github.context.sha = originalSha
       }
     })
 

action.yml

@@ -113,6 +113,6 @@ outputs:
   commit:
     description: 'The commit SHA that was checked out'
 runs:
-  using: node24
+  using: node20
   main: dist/index.js
   post: dist/index.js

dist/index.js

@@ -1895,6 +1895,23 @@ function getInputs() {
             `${github.context.repo.owner}/${github.context.repo.repo}`.toUpperCase();
         // Source branch, source version
         result.ref = core.getInput('ref');
+        // core.getInput()'s default trim strips a range of Unicode characters such as a
+        // leading BOM (U+FEFF) or NBSP (U+00A0). Those are valid in a git ref name, so
+        // a fork branch named "<BOM>" + 40 hex chars would trim down to a bare SHA and
+        // be silently reclassified as a commit, bypassing the unsafe fork PR checkout
+        // guard.
+        //
+        // The trim below strips only the ASCII whitespace characters which are all forbidden
+        // in a git branch name.
+        //   \t  U+0009  horizontal tab   - ASCII control, forbidden in ref names
+        //   \n  U+000A  line feed        - ASCII control, forbidden in ref names
+        //   \v  U+000B  vertical tab     - ASCII control, forbidden in ref names
+        //   \f  U+000C  form feed        - ASCII control, forbidden in ref names
+        //   \r  U+000D  carriage return  - ASCII control, forbidden in ref names
+        //   ' ' U+0020  space            - forbidden in ref names
+        const asciiTrimmedRef = core
+            .getInput('ref', { trimWhitespace: false })
+            .replace(/^[\t\n\v\f\r ]+|[\t\n\v\f\r ]+$/g, '');
         if (!result.ref) {
             if (isWorkflowRepository) {
                 result.ref = github.context.ref;
@@ -1907,8 +1924,8 @@ function getInputs() {
             }
         }
         // SHA?
-        else if (result.ref.match(/^[0-9a-fA-F]{40}$/)) {
-            result.commit = result.ref;
+        else if (asciiTrimmedRef.match(/^[0-9a-fA-F]{40}$/)) {
+            result.commit = asciiTrimmedRef;
             result.ref = '';
         }
         core.debug(`ref = '${result.ref}'`);

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "checkout",
-  "version": "5.0.0",
+  "version": "4.3.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "checkout",
-      "version": "5.0.0",
+      "version": "4.3.0",
       "license": "MIT",
       "dependencies": {
         "@actions/core": "^1.10.1",
@@ -18,7 +18,7 @@
       },
       "devDependencies": {
         "@types/jest": "^29.5.12",
-        "@types/node": "^24.1.0",
+        "@types/node": "^20.12.12",
         "@types/uuid": "^9.0.8",
         "@typescript-eslint/eslint-plugin": "^7.9.0",
         "@typescript-eslint/parser": "^7.9.0",
@@ -1515,12 +1515,12 @@
       "dev": true
     },
     "node_modules/@types/node": {
-      "version": "24.1.0",
-      "resolved": "https://registry.npmjs.org/@types/node/-/node-24.1.0.tgz",
-      "integrity": "sha512-ut5FthK5moxFKH2T1CUOC6ctR67rQRvvHdFLCD2Ql6KXmMuCrjsSsRI9UsLCm9M18BMwClv4pn327UvB7eeO1w==",
+      "version": "20.12.12",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-20.12.12.tgz",
+      "integrity": "sha512-eWLDGF/FOSPtAvEqeRAQ4C8LSA7M1I7i0ky1I8U7kD1J5ITyW3AsRhQrKVoWf5pFKZ2kILsEGJhsI9r93PYnOw==",
       "dev": true,
       "dependencies": {
-        "undici-types": "~7.8.0"
+        "undici-types": "~5.26.4"
       }
     },
     "node_modules/@types/stack-utils": {
@@ -6865,9 +6865,9 @@
       }
     },
     "node_modules/undici-types": {
-      "version": "7.8.0",
-      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-7.8.0.tgz",
-      "integrity": "sha512-9UJ2xGDvQ43tYyVMpuHlsgApydB8ZKfVYTsLDhXkFL/6gfkp+U8xTGdh8pMJv1SpZna0zxG1DwsKZsreLbXBxw==",
+      "version": "5.26.5",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-5.26.5.tgz",
+      "integrity": "sha512-JlCMO+ehdEIKqlFxk6IfVoAUVmgz7cU7zD/h9XZ0qzeosSHmUJVOzSQvvYSYWXkFXC+IfLKSIffhv0sVZup6pA==",
       "dev": true
     },
     "node_modules/universal-user-agent": {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "checkout",
-  "version": "5.0.0",
+  "version": "4.3.0",
   "description": "checkout action",
   "main": "lib/main.js",
   "scripts": {
@@ -37,7 +37,7 @@
   },
   "devDependencies": {
     "@types/jest": "^29.5.12",
-    "@types/node": "^24.1.0",
+    "@types/node": "^20.12.12",
     "@types/uuid": "^9.0.8",
     "@typescript-eslint/eslint-plugin": "^7.9.0",
     "@typescript-eslint/parser": "^7.9.0",

src/input-helper.ts

@@ -59,6 +59,23 @@ export async function getInputs(): Promise<IGitSourceSettings> {
 
   // Source branch, source version
   result.ref = core.getInput('ref')
+  // core.getInput()'s default trim strips a range of Unicode characters such as a
+  // leading BOM (U+FEFF) or NBSP (U+00A0). Those are valid in a git ref name, so
+  // a fork branch named "<BOM>" + 40 hex chars would trim down to a bare SHA and
+  // be silently reclassified as a commit, bypassing the unsafe fork PR checkout
+  // guard.
+  //
+  // The trim below strips only the ASCII whitespace characters which are all forbidden
+  // in a git branch name.
+  //   \t  U+0009  horizontal tab   - ASCII control, forbidden in ref names
+  //   \n  U+000A  line feed        - ASCII control, forbidden in ref names
+  //   \v  U+000B  vertical tab     - ASCII control, forbidden in ref names
+  //   \f  U+000C  form feed        - ASCII control, forbidden in ref names
+  //   \r  U+000D  carriage return  - ASCII control, forbidden in ref names
+  //   ' ' U+0020  space            - forbidden in ref names
+  const asciiTrimmedRef = core
+    .getInput('ref', {trimWhitespace: false})
+    .replace(/^[\t\n\v\f\r ]+|[\t\n\v\f\r ]+$/g, '')
   if (!result.ref) {
     if (isWorkflowRepository) {
       result.ref = github.context.ref
@@ -72,8 +89,8 @@ export async function getInputs(): Promise<IGitSourceSettings> {
     }
   }
   // SHA?
-  else if (result.ref.match(/^[0-9a-fA-F]{40}$/)) {
-    result.commit = result.ref
+  else if (asciiTrimmedRef.match(/^[0-9a-fA-F]{40}$/)) {
+    result.commit = asciiTrimmedRef
     result.ref = ''
   }
   core.debug(`ref = '${result.ref}'`)

src/misc/generate-docs.ts

@@ -120,7 +120,7 @@ function updateUsage(
 }
 
 updateUsage(
-  'actions/checkout@v5',
+  'actions/checkout@v4',
   path.join(__dirname, '..', '..', 'action.yml'),
   path.join(__dirname, '..', '..', 'README.md')
 )