Add support for SHA256 repositories

New input parameter 'repo-sha256' to set the Git object format
to "sha256" when initializing a Git repository.

.github/workflows/test.yml

@@ -87,6 +87,17 @@ jobs:
       - name: Verify fetch filter
         run: __test__/verify-fetch-filter.sh
 
+      # Fetch tags
+      - name: Checkout with fetch-tags
+        uses: ./
+        with:
+          ref: test-data/v2/basic
+          path: fetch-tags-test
+          fetch-tags: true
+      - name: Verify fetch-tags
+        shell: bash
+        run: __test__/verify-fetch-tags.sh
+
       # Sparse checkout
       - name: Sparse checkout
         uses: ./

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## v6.0.2
+* Fix tag handling: preserve annotations and explicit fetch-tags by @ericsciple in https://github.com/actions/checkout/pull/2356
+
+## v6.0.1
+* Add worktree support for persist-credentials includeIf by @ericsciple in https://github.com/actions/checkout/pull/2327
+
 ## v6.0.0
 * Persist creds to a separate file by @ericsciple in https://github.com/actions/checkout/pull/2286
 * Update README to include Node.js 24 support details and requirements by @salmanmkc in https://github.com/actions/checkout/pull/2248

README.md

@@ -160,6 +160,10 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
     # running from unless specified. Example URLs are https://github.com or
     # https://my-ghes-server.example.com
     github-server-url: ''
+
+    # Set Git object format to "sha256" when initializing a Git repository.
+    # Default: false
+    repo-sha256: ''
 ```
 <!-- end usage -->
 

__test__/git-command-manager.test.ts

@@ -108,7 +108,7 @@ describe('Test fetchDepth and fetchTags options', () => {
     jest.restoreAllMocks()
   })
 
-  it('should call execGit with the correct arguments when fetchDepth is 0 and fetchTags is true', async () => {
+  it('should call execGit with the correct arguments when fetchDepth is 0', async () => {
     jest.spyOn(exec, 'exec').mockImplementation(mockExec)
     const workingDirectory = 'test'
     const lfs = false
@@ -122,45 +122,7 @@ describe('Test fetchDepth and fetchTags options', () => {
     const refSpec = ['refspec1', 'refspec2']
     const options = {
       filter: 'filterValue',
-      fetchDepth: 0,
-      fetchTags: true
-    }
-
-    await git.fetch(refSpec, options)
-
-    expect(mockExec).toHaveBeenCalledWith(
-      expect.any(String),
-      [
-        '-c',
-        'protocol.version=2',
-        'fetch',
-        '--prune',
-        '--no-recurse-submodules',
-        '--filter=filterValue',
-        'origin',
-        'refspec1',
-        'refspec2'
-      ],
-      expect.any(Object)
-    )
-  })
-
-  it('should call execGit with the correct arguments when fetchDepth is 0 and fetchTags is false', async () => {
-    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
-
-    const workingDirectory = 'test'
-    const lfs = false
-    const doSparseCheckout = false
-    git = await commandManager.createCommandManager(
-      workingDirectory,
-      lfs,
-      doSparseCheckout
-    )
-    const refSpec = ['refspec1', 'refspec2']
-    const options = {
-      filter: 'filterValue',
-      fetchDepth: 0,
-      fetchTags: false
+      fetchDepth: 0
     }
 
     await git.fetch(refSpec, options)
@@ -183,7 +145,45 @@ describe('Test fetchDepth and fetchTags options', () => {
     )
   })
 
-  it('should call execGit with the correct arguments when fetchDepth is 1 and fetchTags is false', async () => {
+  it('should call execGit with the correct arguments when fetchDepth is 0 and refSpec includes tags', async () => {
+    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+
+    const workingDirectory = 'test'
+    const lfs = false
+    const doSparseCheckout = false
+    git = await commandManager.createCommandManager(
+      workingDirectory,
+      lfs,
+      doSparseCheckout
+    )
+    const refSpec = ['refspec1', 'refspec2', '+refs/tags/*:refs/tags/*']
+    const options = {
+      filter: 'filterValue',
+      fetchDepth: 0
+    }
+
+    await git.fetch(refSpec, options)
+
+    expect(mockExec).toHaveBeenCalledWith(
+      expect.any(String),
+      [
+        '-c',
+        'protocol.version=2',
+        'fetch',
+        '--no-tags',
+        '--prune',
+        '--no-recurse-submodules',
+        '--filter=filterValue',
+        'origin',
+        'refspec1',
+        'refspec2',
+        '+refs/tags/*:refs/tags/*'
+      ],
+      expect.any(Object)
+    )
+  })
+
+  it('should call execGit with the correct arguments when fetchDepth is 1', async () => {
     jest.spyOn(exec, 'exec').mockImplementation(mockExec)
 
     const workingDirectory = 'test'
@@ -197,8 +197,7 @@ describe('Test fetchDepth and fetchTags options', () => {
     const refSpec = ['refspec1', 'refspec2']
     const options = {
       filter: 'filterValue',
-      fetchDepth: 1,
-      fetchTags: false
+      fetchDepth: 1
     }
 
     await git.fetch(refSpec, options)
@@ -222,7 +221,7 @@ describe('Test fetchDepth and fetchTags options', () => {
     )
   })
 
-  it('should call execGit with the correct arguments when fetchDepth is 1 and fetchTags is true', async () => {
+  it('should call execGit with the correct arguments when fetchDepth is 1 and refSpec includes tags', async () => {
     jest.spyOn(exec, 'exec').mockImplementation(mockExec)
 
     const workingDirectory = 'test'
@@ -233,11 +232,10 @@ describe('Test fetchDepth and fetchTags options', () => {
       lfs,
       doSparseCheckout
     )
-    const refSpec = ['refspec1', 'refspec2']
+    const refSpec = ['refspec1', 'refspec2', '+refs/tags/*:refs/tags/*']
     const options = {
       filter: 'filterValue',
-      fetchDepth: 1,
-      fetchTags: true
+      fetchDepth: 1
     }
 
     await git.fetch(refSpec, options)
@@ -248,13 +246,15 @@ describe('Test fetchDepth and fetchTags options', () => {
         '-c',
         'protocol.version=2',
         'fetch',
+        '--no-tags',
         '--prune',
         '--no-recurse-submodules',
         '--filter=filterValue',
         '--depth=1',
         'origin',
         'refspec1',
-        'refspec2'
+        'refspec2',
+        '+refs/tags/*:refs/tags/*'
       ],
       expect.any(Object)
     )
@@ -338,7 +338,7 @@ describe('Test fetchDepth and fetchTags options', () => {
     )
   })
 
-  it('should call execGit with the correct arguments when fetchTags is true and showProgress is true', async () => {
+  it('should call execGit with the correct arguments when showProgress is true and refSpec includes tags', async () => {
     jest.spyOn(exec, 'exec').mockImplementation(mockExec)
 
     const workingDirectory = 'test'
@@ -349,10 +349,9 @@ describe('Test fetchDepth and fetchTags options', () => {
       lfs,
       doSparseCheckout
     )
-    const refSpec = ['refspec1', 'refspec2']
+    const refSpec = ['refspec1', 'refspec2', '+refs/tags/*:refs/tags/*']
     const options = {
       filter: 'filterValue',
-      fetchTags: true,
       showProgress: true
     }
 
@@ -364,15 +363,134 @@ describe('Test fetchDepth and fetchTags options', () => {
         '-c',
         'protocol.version=2',
         'fetch',
+        '--no-tags',
         '--prune',
         '--no-recurse-submodules',
         '--progress',
         '--filter=filterValue',
         'origin',
         'refspec1',
-        'refspec2'
+        'refspec2',
+        '+refs/tags/*:refs/tags/*'
       ],
       expect.any(Object)
     )
   })
 })
+
+describe('git user-agent with orchestration ID', () => {
+  beforeEach(async () => {
+    jest.spyOn(fshelper, 'fileExistsSync').mockImplementation(jest.fn())
+    jest.spyOn(fshelper, 'directoryExistsSync').mockImplementation(jest.fn())
+  })
+
+  afterEach(() => {
+    jest.restoreAllMocks()
+    // Clean up environment variable to prevent test pollution
+    delete process.env['ACTIONS_ORCHESTRATION_ID']
+  })
+
+  it('should include orchestration ID in user-agent when ACTIONS_ORCHESTRATION_ID is set', async () => {
+    const orchId = 'test-orch-id-12345'
+    process.env['ACTIONS_ORCHESTRATION_ID'] = orchId
+
+    let capturedEnv: any = null
+    mockExec.mockImplementation((path, args, options) => {
+      if (args.includes('version')) {
+        options.listeners.stdout(Buffer.from('2.18'))
+      }
+      // Capture env on any command
+      capturedEnv = options.env
+      return 0
+    })
+    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+
+    const workingDirectory = 'test'
+    const lfs = false
+    const doSparseCheckout = false
+    git = await commandManager.createCommandManager(
+      workingDirectory,
+      lfs,
+      doSparseCheckout
+    )
+
+    // Call a git command to trigger env capture after user-agent is set
+    await git.init()
+
+    // Verify the user agent includes the orchestration ID
+    expect(git).toBeDefined()
+    expect(capturedEnv).toBeDefined()
+    expect(capturedEnv['GIT_HTTP_USER_AGENT']).toBe(
+      `git/2.18 (github-actions-checkout) actions_orchestration_id/${orchId}`
+    )
+  })
+
+  it('should sanitize invalid characters in orchestration ID', async () => {
+    const orchId = 'test (with) special/chars'
+    process.env['ACTIONS_ORCHESTRATION_ID'] = orchId
+
+    let capturedEnv: any = null
+    mockExec.mockImplementation((path, args, options) => {
+      if (args.includes('version')) {
+        options.listeners.stdout(Buffer.from('2.18'))
+      }
+      // Capture env on any command
+      capturedEnv = options.env
+      return 0
+    })
+    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+
+    const workingDirectory = 'test'
+    const lfs = false
+    const doSparseCheckout = false
+    git = await commandManager.createCommandManager(
+      workingDirectory,
+      lfs,
+      doSparseCheckout
+    )
+
+    // Call a git command to trigger env capture after user-agent is set
+    await git.init()
+
+    // Verify the user agent has sanitized orchestration ID (spaces, parentheses, slash replaced)
+    expect(git).toBeDefined()
+    expect(capturedEnv).toBeDefined()
+    expect(capturedEnv['GIT_HTTP_USER_AGENT']).toBe(
+      'git/2.18 (github-actions-checkout) actions_orchestration_id/test__with__special_chars'
+    )
+  })
+
+  it('should not modify user-agent when ACTIONS_ORCHESTRATION_ID is not set', async () => {
+    delete process.env['ACTIONS_ORCHESTRATION_ID']
+
+    let capturedEnv: any = null
+    mockExec.mockImplementation((path, args, options) => {
+      if (args.includes('version')) {
+        options.listeners.stdout(Buffer.from('2.18'))
+      }
+      // Capture env on any command
+      capturedEnv = options.env
+      return 0
+    })
+    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+
+    const workingDirectory = 'test'
+    const lfs = false
+    const doSparseCheckout = false
+    git = await commandManager.createCommandManager(
+      workingDirectory,
+      lfs,
+      doSparseCheckout
+    )
+
+    // Call a git command to trigger env capture after user-agent is set
+    await git.init()
+
+    // Verify the user agent does NOT contain orchestration ID
+    expect(git).toBeDefined()
+    expect(capturedEnv).toBeDefined()
+    expect(capturedEnv['GIT_HTTP_USER_AGENT']).toBe(
+      'git/2.18 (github-actions-checkout)'
+    )
+  })
+})

__test__/ref-helper.test.ts

@@ -152,7 +152,22 @@ describe('ref-helper tests', () => {
   it('getRefSpec sha + refs/tags/', async () => {
     const refSpec = refHelper.getRefSpec('refs/tags/my-tag', commit)
     expect(refSpec.length).toBe(1)
-    expect(refSpec[0]).toBe(`+${commit}:refs/tags/my-tag`)
+    expect(refSpec[0]).toBe(`+refs/tags/my-tag:refs/tags/my-tag`)
+  })
+
+  it('getRefSpec sha + refs/tags/ with fetchTags', async () => {
+    // When fetchTags is true, only include tags wildcard (specific tag is redundant)
+    const refSpec = refHelper.getRefSpec('refs/tags/my-tag', commit, true)
+    expect(refSpec.length).toBe(1)
+    expect(refSpec[0]).toBe('+refs/tags/*:refs/tags/*')
+  })
+
+  it('getRefSpec sha + refs/heads/ with fetchTags', async () => {
+    // When fetchTags is true, include both the branch refspec and tags wildcard
+    const refSpec = refHelper.getRefSpec('refs/heads/my/branch', commit, true)
+    expect(refSpec.length).toBe(2)
+    expect(refSpec[0]).toBe('+refs/tags/*:refs/tags/*')
+    expect(refSpec[1]).toBe(`+${commit}:refs/remotes/origin/my/branch`)
   })
 
   it('getRefSpec sha only', async () => {
@@ -168,6 +183,14 @@ describe('ref-helper tests', () => {
     expect(refSpec[1]).toBe('+refs/tags/my-ref*:refs/tags/my-ref*')
   })
 
+  it('getRefSpec unqualified ref only with fetchTags', async () => {
+    // When fetchTags is true, skip specific tag pattern since wildcard covers all
+    const refSpec = refHelper.getRefSpec('my-ref', '', true)
+    expect(refSpec.length).toBe(2)
+    expect(refSpec[0]).toBe('+refs/tags/*:refs/tags/*')
+    expect(refSpec[1]).toBe('+refs/heads/my-ref*:refs/remotes/origin/my-ref*')
+  })
+
   it('getRefSpec refs/heads/ only', async () => {
     const refSpec = refHelper.getRefSpec('refs/heads/my/branch', '')
     expect(refSpec.length).toBe(1)
@@ -187,4 +210,21 @@ describe('ref-helper tests', () => {
     expect(refSpec.length).toBe(1)
     expect(refSpec[0]).toBe('+refs/tags/my-tag:refs/tags/my-tag')
   })
+
+  it('getRefSpec refs/tags/ only with fetchTags', async () => {
+    // When fetchTags is true, only include tags wildcard (specific tag is redundant)
+    const refSpec = refHelper.getRefSpec('refs/tags/my-tag', '', true)
+    expect(refSpec.length).toBe(1)
+    expect(refSpec[0]).toBe('+refs/tags/*:refs/tags/*')
+  })
+
+  it('getRefSpec refs/heads/ only with fetchTags', async () => {
+    // When fetchTags is true, include both the branch refspec and tags wildcard
+    const refSpec = refHelper.getRefSpec('refs/heads/my/branch', '', true)
+    expect(refSpec.length).toBe(2)
+    expect(refSpec[0]).toBe('+refs/tags/*:refs/tags/*')
+    expect(refSpec[1]).toBe(
+      '+refs/heads/my/branch:refs/remotes/origin/my/branch'
+    )
+  })
 })

__test__/verify-fetch-tags.sh

@@ -0,0 +1,9 @@
+#!/bin/sh
+
+# Verify tags were fetched
+TAG_COUNT=$(git -C ./fetch-tags-test tag | wc -l)
+if [ "$TAG_COUNT" -eq 0 ]; then
+    echo "Expected tags to be fetched, but found none"
+    exit 1
+fi
+echo "Found $TAG_COUNT tags"

action.yml

@@ -98,6 +98,10 @@ inputs:
   github-server-url:
     description: The base URL for the GitHub instance that you are trying to clone from, will use environment defaults to fetch from the same instance that the workflow is running from unless specified. Example URLs are https://github.com or https://my-ghes-server.example.com
     required: false
+  repo-sha256:
+    description: 'Set Git object format to "sha256" when initializing a Git repository.'
+    required: false
+    default: false
 outputs:
   ref:
     description: 'The branch, tag or SHA that was checked out'

dist/index.js

@@ -653,7 +653,6 @@ const fs = __importStar(__nccwpck_require__(7147));
 const fshelper = __importStar(__nccwpck_require__(7219));
 const io = __importStar(__nccwpck_require__(7436));
 const path = __importStar(__nccwpck_require__(1017));
-const refHelper = __importStar(__nccwpck_require__(8601));
 const regexpHelper = __importStar(__nccwpck_require__(3120));
 const retryHelper = __importStar(__nccwpck_require__(2155));
 const git_version_1 = __nccwpck_require__(3142);
@@ -831,9 +830,9 @@ class GitCommandManager {
     fetch(refSpec, options) {
         return __awaiter(this, void 0, void 0, function* () {
             const args = ['-c', 'protocol.version=2', 'fetch'];
-            if (!refSpec.some(x => x === refHelper.tagsRefSpec) && !options.fetchTags) {
-                args.push('--no-tags');
-            }
+            // Always use --no-tags for explicit control over tag fetching
+            // Tags are fetched explicitly via refspec when needed
+            args.push('--no-tags');
             args.push('--prune', '--no-recurse-submodules');
             if (options.showProgress) {
                 args.push('--progress');
@@ -897,9 +896,14 @@ class GitCommandManager {
     getWorkingDirectory() {
         return this.workingDirectory;
     }
-    init() {
+    init(repoSHA256) {
         return __awaiter(this, void 0, void 0, function* () {
-            yield this.execGit(['init', this.workingDirectory]);
+            const args = ['init'];
+            if (repoSHA256) {
+                args.push(`--object-format=sha256`);
+            }
+            args.push(this.workingDirectory);
+            yield this.execGit(args);
         });
     }
     isDetached() {
@@ -1206,7 +1210,17 @@ class GitCommandManager {
                 }
             }
             // Set the user agent
-            const gitHttpUserAgent = `git/${this.gitVersion} (github-actions-checkout)`;
+            let gitHttpUserAgent = `git/${this.gitVersion} (github-actions-checkout)`;
+            // Append orchestration ID if set
+            const orchId = process.env['ACTIONS_ORCHESTRATION_ID'];
+            if (orchId) {
+                // Sanitize the orchestration ID to ensure it contains only valid characters
+                // Valid characters: 0-9, a-z, _, -, .
+                const sanitizedId = orchId.replace(/[^a-z0-9_.-]/gi, '_');
+                if (sanitizedId) {
+                    gitHttpUserAgent = `${gitHttpUserAgent} actions_orchestration_id/${sanitizedId}`;
+                }
+            }
             core.debug(`Set git useragent to: ${gitHttpUserAgent}`);
             this.gitEnv['GIT_HTTP_USER_AGENT'] = gitHttpUserAgent;
         });
@@ -1478,7 +1492,7 @@ function getSource(settings) {
             // Initialize the repository
             if (!fsHelper.directoryExistsSync(path.join(settings.repositoryPath, '.git'))) {
                 core.startGroup('Initializing the repository');
-                yield git.init();
+                yield git.init(settings.repoSHA256);
                 yield git.remoteAdd('origin', repositoryUrl);
                 core.endGroup();
             }
@@ -1529,13 +1543,26 @@ function getSource(settings) {
                 if (!(yield refHelper.testRef(git, settings.ref, settings.commit))) {
                     refSpec = refHelper.getRefSpec(settings.ref, settings.commit);
                     yield git.fetch(refSpec, fetchOptions);
+                    // Verify the ref now matches. For branches, the targeted fetch above brings
+                    // in the specific commit. For tags (fetched by ref), this will fail if
+                    // the tag was moved after the workflow was triggered.
+                    if (!(yield refHelper.testRef(git, settings.ref, settings.commit))) {
+                        throw new Error(`The ref '${settings.ref}' does not point to the expected commit '${settings.commit}'. ` +
+                            `The ref may have been updated after the workflow was triggered.`);
+                    }
                 }
             }
             else {
                 fetchOptions.fetchDepth = settings.fetchDepth;
-                fetchOptions.fetchTags = settings.fetchTags;
-                const refSpec = refHelper.getRefSpec(settings.ref, settings.commit);
+                const refSpec = refHelper.getRefSpec(settings.ref, settings.commit, settings.fetchTags);
                 yield git.fetch(refSpec, fetchOptions);
+                // For tags, verify the ref still points to the expected commit.
+                // Tags are fetched by ref (not commit), so if a tag was moved after the
+                // workflow was triggered, we would silently check out the wrong commit.
+                if (!(yield refHelper.testRef(git, settings.ref, settings.commit))) {
+                    throw new Error(`The ref '${settings.ref}' does not point to the expected commit '${settings.commit}'. ` +
+                        `The ref may have been updated after the workflow was triggered.`);
+                }
             }
             core.endGroup();
             // Checkout info
@@ -2073,6 +2100,10 @@ function getInputs() {
         // Determine the GitHub URL that the repository is being hosted from
         result.githubServerUrl = core.getInput('github-server-url');
         core.debug(`GitHub Host URL = ${result.githubServerUrl}`);
+        // Set Git object format to "sha256" when initializing a Git repository.
+        result.repoSHA256 =
+            (core.getInput('repo-sha256') || 'false').toUpperCase() === 'TRUE';
+        core.debug(`Repo object format sha256 = ${result.repoSHA256}`);
         return result;
     });
 }
@@ -2274,53 +2305,67 @@ function getRefSpecForAllHistory(ref, commit) {
     }
     return result;
 }
-function getRefSpec(ref, commit) {
+function getRefSpec(ref, commit, fetchTags) {
     if (!ref && !commit) {
         throw new Error('Args ref and commit cannot both be empty');
     }
     const upperRef = (ref || '').toUpperCase();
+    const result = [];
+    // When fetchTags is true, always include the tags refspec
+    if (fetchTags) {
+        result.push(exports.tagsRefSpec);
+    }
     // SHA
     if (commit) {
         // refs/heads
         if (upperRef.startsWith('REFS/HEADS/')) {
             const branch = ref.substring('refs/heads/'.length);
-            return [`+${commit}:refs/remotes/origin/${branch}`];
+            result.push(`+${commit}:refs/remotes/origin/${branch}`);
         }
         // refs/pull/
         else if (upperRef.startsWith('REFS/PULL/')) {
             const branch = ref.substring('refs/pull/'.length);
-            return [`+${commit}:refs/remotes/pull/${branch}`];
+            result.push(`+${commit}:refs/remotes/pull/${branch}`);
         }
         // refs/tags/
         else if (upperRef.startsWith('REFS/TAGS/')) {
-            return [`+${commit}:${ref}`];
+            if (!fetchTags) {
+                result.push(`+${ref}:${ref}`);
+            }
         }
         // Otherwise no destination ref
         else {
-            return [commit];
+            result.push(commit);
         }
     }
     // Unqualified ref, check for a matching branch or tag
     else if (!upperRef.startsWith('REFS/')) {
-        return [
-            `+refs/heads/${ref}*:refs/remotes/origin/${ref}*`,
-            `+refs/tags/${ref}*:refs/tags/${ref}*`
-        ];
+        result.push(`+refs/heads/${ref}*:refs/remotes/origin/${ref}*`);
+        if (!fetchTags) {
+            result.push(`+refs/tags/${ref}*:refs/tags/${ref}*`);
+        }
     }
     // refs/heads/
     else if (upperRef.startsWith('REFS/HEADS/')) {
         const branch = ref.substring('refs/heads/'.length);
-        return [`+${ref}:refs/remotes/origin/${branch}`];
+        result.push(`+${ref}:refs/remotes/origin/${branch}`);
     }
     // refs/pull/
     else if (upperRef.startsWith('REFS/PULL/')) {
         const branch = ref.substring('refs/pull/'.length);
-        return [`+${ref}:refs/remotes/pull/${branch}`];
+        result.push(`+${ref}:refs/remotes/pull/${branch}`);
     }
     // refs/tags/
-    else {
-        return [`+${ref}:${ref}`];
+    else if (upperRef.startsWith('REFS/TAGS/')) {
+        if (!fetchTags) {
+            result.push(`+${ref}:${ref}`);
+        }
     }
+    // Other refs
+    else {
+        result.push(`+${ref}:${ref}`);
+    }
+    return result;
 }
 /**
  * Tests whether the initial fetch created the ref at the expected commit
@@ -2356,7 +2401,9 @@ function testRef(git, ref, commit) {
         // refs/tags/
         else if (upperRef.startsWith('REFS/TAGS/')) {
             const tagName = ref.substring('refs/tags/'.length);
-            return ((yield git.tagExists(tagName)) && commit === (yield git.revParse(ref)));
+            // Use ^{commit} to dereference annotated tags to their underlying commit
+            return ((yield git.tagExists(tagName)) &&
+                commit === (yield git.revParse(`${ref}^{commit}`)));
         }
         // Unexpected
         else {

src/git-command-manager.ts

@@ -37,14 +37,13 @@ export interface IGitCommandManager {
     options: {
       filter?: string
       fetchDepth?: number
-      fetchTags?: boolean
       showProgress?: boolean
     }
   ): Promise<void>
   getDefaultBranch(repositoryUrl: string): Promise<string>
   getSubmoduleConfigPaths(recursive: boolean): Promise<string[]>
   getWorkingDirectory(): string
-  init(): Promise<void>
+  init(repoSHA256?: boolean): Promise<void>
   isDetached(): Promise<boolean>
   lfsFetch(ref: string): Promise<void>
   lfsInstall(): Promise<void>
@@ -280,14 +279,13 @@ class GitCommandManager {
     options: {
       filter?: string
       fetchDepth?: number
-      fetchTags?: boolean
       showProgress?: boolean
     }
   ): Promise<void> {
     const args = ['-c', 'protocol.version=2', 'fetch']
-    if (!refSpec.some(x => x === refHelper.tagsRefSpec) && !options.fetchTags) {
-      args.push('--no-tags')
-    }
+    // Always use --no-tags for explicit control over tag fetching
+    // Tags are fetched explicitly via refspec when needed
+    args.push('--no-tags')
 
     args.push('--prune', '--no-recurse-submodules')
     if (options.showProgress) {
@@ -366,8 +364,13 @@ class GitCommandManager {
     return this.workingDirectory
   }
 
-  async init(): Promise<void> {
-    await this.execGit(['init', this.workingDirectory])
+  async init(repoSHA256?: boolean): Promise<void> {
+    const args = ['init']
+    if (repoSHA256) {
+      args.push(`--object-format=sha256`)
+    }
+    args.push(this.workingDirectory)
+    await this.execGit(args)
   }
 
   async isDetached(): Promise<boolean> {
@@ -730,7 +733,19 @@ class GitCommandManager {
       }
     }
     // Set the user agent
-    const gitHttpUserAgent = `git/${this.gitVersion} (github-actions-checkout)`
+    let gitHttpUserAgent = `git/${this.gitVersion} (github-actions-checkout)`
+
+    // Append orchestration ID if set
+    const orchId = process.env['ACTIONS_ORCHESTRATION_ID']
+    if (orchId) {
+      // Sanitize the orchestration ID to ensure it contains only valid characters
+      // Valid characters: 0-9, a-z, _, -, .
+      const sanitizedId = orchId.replace(/[^a-z0-9_.-]/gi, '_')
+      if (sanitizedId) {
+        gitHttpUserAgent = `${gitHttpUserAgent} actions_orchestration_id/${sanitizedId}`
+      }
+    }
+
     core.debug(`Set git useragent to: ${gitHttpUserAgent}`)
     this.gitEnv['GIT_HTTP_USER_AGENT'] = gitHttpUserAgent
   }

src/git-source-provider.ts

@@ -110,7 +110,7 @@ export async function getSource(settings: IGitSourceSettings): Promise<void> {
       !fsHelper.directoryExistsSync(path.join(settings.repositoryPath, '.git'))
     ) {
       core.startGroup('Initializing the repository')
-      await git.init()
+      await git.init(settings.repoSHA256)
       await git.remoteAdd('origin', repositoryUrl)
       core.endGroup()
     }
@@ -159,7 +159,6 @@ export async function getSource(settings: IGitSourceSettings): Promise<void> {
     const fetchOptions: {
       filter?: string
       fetchDepth?: number
-      fetchTags?: boolean
       showProgress?: boolean
     } = {}
 
@@ -182,12 +181,35 @@ export async function getSource(settings: IGitSourceSettings): Promise<void> {
       if (!(await refHelper.testRef(git, settings.ref, settings.commit))) {
         refSpec = refHelper.getRefSpec(settings.ref, settings.commit)
         await git.fetch(refSpec, fetchOptions)
+
+        // Verify the ref now matches. For branches, the targeted fetch above brings
+        // in the specific commit. For tags (fetched by ref), this will fail if
+        // the tag was moved after the workflow was triggered.
+        if (!(await refHelper.testRef(git, settings.ref, settings.commit))) {
+          throw new Error(
+            `The ref '${settings.ref}' does not point to the expected commit '${settings.commit}'. ` +
+              `The ref may have been updated after the workflow was triggered.`
+          )
+        }
       }
     } else {
       fetchOptions.fetchDepth = settings.fetchDepth
-      fetchOptions.fetchTags = settings.fetchTags
-      const refSpec = refHelper.getRefSpec(settings.ref, settings.commit)
+      const refSpec = refHelper.getRefSpec(
+        settings.ref,
+        settings.commit,
+        settings.fetchTags
+      )
       await git.fetch(refSpec, fetchOptions)
+
+      // For tags, verify the ref still points to the expected commit.
+      // Tags are fetched by ref (not commit), so if a tag was moved after the
+      // workflow was triggered, we would silently check out the wrong commit.
+      if (!(await refHelper.testRef(git, settings.ref, settings.commit))) {
+        throw new Error(
+          `The ref '${settings.ref}' does not point to the expected commit '${settings.commit}'. ` +
+            `The ref may have been updated after the workflow was triggered.`
+        )
+      }
     }
     core.endGroup()
 

src/git-source-settings.ts

@@ -118,4 +118,9 @@ export interface IGitSourceSettings {
    * User override on the GitHub Server/Host URL that hosts the repository to be cloned
    */
   githubServerUrl: string | undefined
+
+  /**
+   * Set Git object format to "sha256" when initializing a Git repository
+   */
+  repoSHA256: boolean
 }

src/input-helper.ts

@@ -161,5 +161,10 @@ export async function getInputs(): Promise<IGitSourceSettings> {
   result.githubServerUrl = core.getInput('github-server-url')
   core.debug(`GitHub Host URL = ${result.githubServerUrl}`)
 
+  // Set Git object format to "sha256" when initializing a Git repository.
+  result.repoSHA256 =
+    (core.getInput('repo-sha256') || 'false').toUpperCase() === 'TRUE'
+  core.debug(`Repo object format sha256 = ${result.repoSHA256}`)
+
   return result
 }

src/ref-helper.ts

@@ -76,55 +76,75 @@ export function getRefSpecForAllHistory(ref: string, commit: string): string[] {
   return result
 }
 
-export function getRefSpec(ref: string, commit: string): string[] {
+export function getRefSpec(
+  ref: string,
+  commit: string,
+  fetchTags?: boolean
+): string[] {
   if (!ref && !commit) {
     throw new Error('Args ref and commit cannot both be empty')
   }
 
   const upperRef = (ref || '').toUpperCase()
+  const result: string[] = []
+
+  // When fetchTags is true, always include the tags refspec
+  if (fetchTags) {
+    result.push(tagsRefSpec)
+  }
 
   // SHA
   if (commit) {
     // refs/heads
     if (upperRef.startsWith('REFS/HEADS/')) {
       const branch = ref.substring('refs/heads/'.length)
-      return [`+${commit}:refs/remotes/origin/${branch}`]
+      result.push(`+${commit}:refs/remotes/origin/${branch}`)
     }
     // refs/pull/
     else if (upperRef.startsWith('REFS/PULL/')) {
       const branch = ref.substring('refs/pull/'.length)
-      return [`+${commit}:refs/remotes/pull/${branch}`]
+      result.push(`+${commit}:refs/remotes/pull/${branch}`)
     }
     // refs/tags/
     else if (upperRef.startsWith('REFS/TAGS/')) {
-      return [`+${commit}:${ref}`]
+      if (!fetchTags) {
+        result.push(`+${ref}:${ref}`)
+      }
     }
     // Otherwise no destination ref
     else {
-      return [commit]
+      result.push(commit)
     }
   }
   // Unqualified ref, check for a matching branch or tag
   else if (!upperRef.startsWith('REFS/')) {
-    return [
-      `+refs/heads/${ref}*:refs/remotes/origin/${ref}*`,
-      `+refs/tags/${ref}*:refs/tags/${ref}*`
-    ]
+    result.push(`+refs/heads/${ref}*:refs/remotes/origin/${ref}*`)
+    if (!fetchTags) {
+      result.push(`+refs/tags/${ref}*:refs/tags/${ref}*`)
+    }
   }
   // refs/heads/
   else if (upperRef.startsWith('REFS/HEADS/')) {
     const branch = ref.substring('refs/heads/'.length)
-    return [`+${ref}:refs/remotes/origin/${branch}`]
+    result.push(`+${ref}:refs/remotes/origin/${branch}`)
   }
   // refs/pull/
   else if (upperRef.startsWith('REFS/PULL/')) {
     const branch = ref.substring('refs/pull/'.length)
-    return [`+${ref}:refs/remotes/pull/${branch}`]
+    result.push(`+${ref}:refs/remotes/pull/${branch}`)
   }
   // refs/tags/
-  else {
-    return [`+${ref}:${ref}`]
+  else if (upperRef.startsWith('REFS/TAGS/')) {
+    if (!fetchTags) {
+      result.push(`+${ref}:${ref}`)
+    }
   }
+  // Other refs
+  else {
+    result.push(`+${ref}:${ref}`)
+  }
+
+  return result
 }
 
 /**
@@ -170,8 +190,10 @@ export async function testRef(
   // refs/tags/
   else if (upperRef.startsWith('REFS/TAGS/')) {
     const tagName = ref.substring('refs/tags/'.length)
+    // Use ^{commit} to dereference annotated tags to their underlying commit
     return (
-      (await git.tagExists(tagName)) && commit === (await git.revParse(ref))
+      (await git.tagExists(tagName)) &&
+      commit === (await git.revParse(`${ref}^{commit}`))
     )
   }
   // Unexpected