fix: expand merge commit SHA regex and add SHA-256 test cases (#2414)

* fix: expand merge commit SHA regex and add SHA-256 test cases

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* test: add checkCommitInfo SHA coverage

Add checkCommitInfo tests for SHA-1 and SHA-256 merge messages and reject invalid 50-character hex merge heads.\n\nCo-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* style: fix Prettier formatting in test and source files

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

.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

__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,
+      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
     }
 
     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,
+      fetchDepth: 1
-      fetchTags: false
     }
 
     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,
+      fetchDepth: 1
-      fetchTags: true
     }
 
     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__/input-helper.test.ts

@@ -133,6 +133,16 @@ describe('input-helper tests', () => {
     expect(settings.commit).toBe('1111111111222222222233333333334444444444')
   })
 
+  it('sets ref to empty when explicit sha-256', async () => {
+    inputs.ref =
+      '1111111111222222222233333333334444444444555555555566666666667777'
+    const settings: IGitSourceSettings = await inputHelper.getInputs()
+    expect(settings.ref).toBeFalsy()
+    expect(settings.commit).toBe(
+      '1111111111222222222233333333334444444444555555555566666666667777'
+    )
+  })
+
   it('sets sha to empty when explicit ref', async () => {
     inputs.ref = 'refs/heads/some-other-ref'
     const settings: IGitSourceSettings = await inputHelper.getInputs()

__test__/ref-helper.test.ts

@@ -1,8 +1,12 @@
 import * as assert from 'assert'
+import * as core from '@actions/core'
+import * as github from '@actions/github'
 import * as refHelper from '../lib/ref-helper'
 import {IGitCommandManager} from '../lib/git-command-manager'
 
 const commit = '1234567890123456789012345678901234567890'
+const sha256Commit =
+  '1234567890123456789012345678901234567890123456789012345678901234'
 let git: IGitCommandManager
 
 describe('ref-helper tests', () => {
@@ -37,6 +41,12 @@ describe('ref-helper tests', () => {
     expect(checkoutInfo.startPoint).toBeFalsy()
   })
 
+  it('getCheckoutInfo sha-256 only', async () => {
+    const checkoutInfo = await refHelper.getCheckoutInfo(git, '', sha256Commit)
+    expect(checkoutInfo.ref).toBe(sha256Commit)
+    expect(checkoutInfo.startPoint).toBeFalsy()
+  })
+
   it('getCheckoutInfo refs/heads/', async () => {
     const checkoutInfo = await refHelper.getCheckoutInfo(
       git,
@@ -152,7 +162,22 @@ 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 +193,14 @@ 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 +220,159 @@ 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'
+    )
+  })
+
+  describe('checkCommitInfo', () => {
+    const repositoryOwner = 'some-owner'
+    const repositoryName = 'some-repo'
+    const ref = 'refs/pull/123/merge'
+    const sha1Head = '1111111111222222222233333333334444444444'
+    const sha1Base = 'aaaaaaaaaabbbbbbbbbbccccccccccdddddddddd'
+    const sha256Head =
+      '1111111111222222222233333333334444444444555555555566666666667777'
+    const sha256Base =
+      'aaaaaaaaaabbbbbbbbbbccccccccccddddddddddeeeeeeeeeeffffffffff0000'
+    let debugSpy: jest.SpyInstance
+    let getOctokitSpy: jest.SpyInstance
+    let repoGetSpy: jest.Mock
+    let originalEventName: string
+    let originalPayload: unknown
+    let originalRef: string
+    let originalSha: string
+
+    function setPullRequestContext(
+      expectedHeadSha: string,
+      expectedBaseSha: string,
+      mergeCommit: string
+    ): void {
+      ;(github.context as any).eventName = 'pull_request'
+      github.context.ref = ref
+      github.context.sha = mergeCommit
+      ;(github.context as any).payload = {
+        action: 'synchronize',
+        after: expectedHeadSha,
+        number: 123,
+        pull_request: {
+          base: {
+            sha: expectedBaseSha
+          }
+        },
+        repository: {
+          private: false
+        }
+      }
+    }
+
+    beforeEach(() => {
+      originalEventName = github.context.eventName
+      originalPayload = github.context.payload
+      originalRef = github.context.ref
+      originalSha = github.context.sha
+
+      jest.spyOn(github.context, 'repo', 'get').mockReturnValue({
+        owner: repositoryOwner,
+        repo: repositoryName
+      })
+      debugSpy = jest.spyOn(core, 'debug').mockImplementation(jest.fn())
+      repoGetSpy = jest.fn(async () => ({}))
+      getOctokitSpy = jest.spyOn(github, 'getOctokit').mockReturnValue({
+        rest: {
+          repos: {
+            get: repoGetSpy
+          }
+        }
+      } as any)
+    })
+
+    afterEach(() => {
+      ;(github.context as any).eventName = originalEventName
+      ;(github.context as any).payload = originalPayload
+      github.context.ref = originalRef
+      github.context.sha = originalSha
+      jest.restoreAllMocks()
+    })
+
+    it('returns early for SHA-1 merge commit', async () => {
+      setPullRequestContext(sha1Head, sha1Base, commit)
+
+      await refHelper.checkCommitInfo(
+        'token',
+        `Merge ${sha1Head} into ${sha1Base}`,
+        repositoryOwner,
+        repositoryName,
+        ref,
+        commit
+      )
+
+      expect(getOctokitSpy).not.toHaveBeenCalled()
+      expect(repoGetSpy).not.toHaveBeenCalled()
+    })
+
+    it('matches SHA-256 merge commit info', async () => {
+      const actualHeadSha =
+        '9999999999888888888877777777776666666666555555555544444444443333'
+      setPullRequestContext(sha256Head, sha256Base, sha256Commit)
+
+      await refHelper.checkCommitInfo(
+        'token',
+        `Merge ${actualHeadSha} into ${sha256Base}`,
+        repositoryOwner,
+        repositoryName,
+        ref,
+        sha256Commit
+      )
+
+      expect(getOctokitSpy).toHaveBeenCalledWith(
+        'token',
+        expect.objectContaining({
+          userAgent: expect.stringContaining(
+            `expected_head_sha=${sha256Head};actual_head_sha=${actualHeadSha}`
+          )
+        })
+      )
+      expect(repoGetSpy).toHaveBeenCalledWith({
+        owner: repositoryOwner,
+        repo: repositoryName
+      })
+      expect(debugSpy).toHaveBeenCalledWith(
+        `Expected head sha ${sha256Head}; actual head sha ${actualHeadSha}`
+      )
+      expect(debugSpy).not.toHaveBeenCalledWith('Unexpected message format')
+    })
+
+    it('does not match 50-char hex as a valid merge', async () => {
+      const invalidHeadSha =
+        '99999999998888888888777777777766666666665555555555'
+      setPullRequestContext(sha1Head, sha1Base, commit)
+
+      await refHelper.checkCommitInfo(
+        'token',
+        `Merge ${invalidHeadSha} into ${sha1Base}`,
+        repositoryOwner,
+        repositoryName,
+        ref,
+        commit
+      )
+
+      expect(getOctokitSpy).not.toHaveBeenCalled()
+      expect(repoGetSpy).not.toHaveBeenCalled()
+      expect(debugSpy).toHaveBeenCalledWith('Unexpected message format')
+    })
+  })
 })

__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"

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) {
+            // Always use --no-tags for explicit control over tag fetching
-                args.push('--no-tags');
+            // Tags are fetched explicitly via refspec when needed
-            }
+            args.push('--no-tags');
             args.push('--prune', '--no-recurse-submodules');
             if (options.showProgress) {
                 args.push('--progress');
@@ -1206,7 +1205,17 @@ 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: ${gitHttpUserAgent}`);
             this.gitEnv['GIT_HTTP_USER_AGENT'] = gitHttpUserAgent;
         });
@@ -1529,13 +1538,26 @@ function getSource(settings) {
                 if (!(yield refHelper.testRef(git, settings.ref, settings.commit))) {
                     refSpec = refHelper.getRefSpec(settings.ref, settings.commit);
                     yield git.fetch(refSpec, fetchOptions);
+                    // Verify the ref now matches. For branches, the targeted fetch above brings
+                    // in the specific commit. For tags (fetched by ref), this will fail if
+                    // the tag was moved after the workflow was triggered.
+                    if (!(yield refHelper.testRef(git, settings.ref, settings.commit))) {
+                        throw new Error(`The ref '${settings.ref}' does not point to the expected commit '${settings.commit}'. ` +
+                            `The ref may have been updated after the workflow was triggered.`);
+                    }
                 }
             }
             else {
                 fetchOptions.fetchDepth = settings.fetchDepth;
-                fetchOptions.fetchTags = settings.fetchTags;
+                const refSpec = refHelper.getRefSpec(settings.ref, settings.commit, settings.fetchTags);
-                const refSpec = refHelper.getRefSpec(settings.ref, settings.commit);
                 yield git.fetch(refSpec, fetchOptions);
+                // For tags, verify the ref still points to the expected commit.
+                // Tags are fetched by ref (not commit), so if a tag was moved after the
+                // workflow was triggered, we would silently check out the wrong commit.
+                if (!(yield refHelper.testRef(git, settings.ref, settings.commit))) {
+                    throw new Error(`The ref '${settings.ref}' does not point to the expected commit '${settings.commit}'. ` +
+                        `The ref may have been updated after the workflow was triggered.`);
+                }
             }
             core.endGroup();
             // Checkout info
@@ -1999,7 +2021,7 @@ function getInputs() {
             }
         }
         // SHA?
-        else if (result.ref.match(/^[0-9a-fA-F]{40}$/)) {
+        else if (result.ref.match(/^(?:[0-9a-fA-F]{40}|[0-9a-fA-F]{64})$/)) {
             result.commit = result.ref;
             result.ref = '';
         }
@@ -2274,53 +2296,67 @@ function getRefSpecForAllHistory(ref, commit) {
     }
     return result;
 }
-function getRefSpec(ref, commit) {
+function getRefSpec(ref, commit, fetchTags) {
     if (!ref && !commit) {
         throw new Error('Args ref and commit cannot both be empty');
     }
     const upperRef = (ref || '').toUpperCase();
+    const result = [];
+    // When fetchTags is true, always include the tags refspec
+    if (fetchTags) {
+        result.push(exports.tagsRefSpec);
+    }
     // SHA
     if (commit) {
         // refs/heads
         if (upperRef.startsWith('REFS/HEADS/')) {
             const branch = ref.substring('refs/heads/'.length);
-            return [`+${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}:${ref}`);
+            }
         }
         // Otherwise no destination ref
         else {
-            return [commit];
+            result.push(commit);
         }
     }
     // Unqualified ref, check for a matching branch or tag
     else if (!upperRef.startsWith('REFS/')) {
-        return [
+        result.push(`+refs/heads/${ref}*:refs/remotes/origin/${ref}*`);
-            `+refs/heads/${ref}*:refs/remotes/origin/${ref}*`,
+        if (!fetchTags) {
-            `+refs/tags/${ref}*:refs/tags/${ref}*`
+            result.push(`+refs/tags/${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/${branch}`);
     }
     // refs/tags/
-    else {
+    else if (upperRef.startsWith('REFS/TAGS/')) {
-        return [`+${ref}:${ref}`];
+        if (!fetchTags) {
+            result.push(`+${ref}:${ref}`);
+        }
     }
+    // Other refs
+    else {
+        result.push(`+${ref}:${ref}`);
+    }
+    return result;
 }
 /**
  * Tests whether the initial fetch created the ref at the expected commit
@@ -2356,7 +2392,9 @@ function testRef(git, ref, commit) {
         // refs/tags/
         else if (upperRef.startsWith('REFS/TAGS/')) {
             const tagName = ref.substring('refs/tags/'.length);
-            return ((yield git.tagExists(tagName)) && commit === (yield git.revParse(ref)));
+            // Use ^{commit} to dereference annotated tags to their underlying commit
+            return ((yield git.tagExists(tagName)) &&
+                commit === (yield git.revParse(`${ref}^{commit}`)));
         }
         // Unexpected
         else {
@@ -2406,7 +2444,7 @@ function checkCommitInfo(token, commitInfo, repositoryOwner, repositoryName, ref
                 return;
             }
             // Extract details from message
-            const match = commitInfo.match(/Merge ([0-9a-f]{40}) into ([0-9a-f]{40})/);
+            const match = commitInfo.match(/Merge ([0-9a-f]{40}|[0-9a-f]{64}) into ([0-9a-f]{40}|[0-9a-f]{64})/);
             if (!match) {
                 core.debug('Unexpected message format');
                 return;

src/git-command-manager.ts

@@ -37,7 +37,6 @@ export interface IGitCommandManager {
     options: {
       filter?: string
       fetchDepth?: number
-      fetchTags?: boolean
       showProgress?: boolean
     }
   ): 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) {
+    // Always use --no-tags for explicit control over tag fetching
-      args.push('--no-tags')
+    // Tags are fetched explicitly via refspec when needed
-    }
+    args.push('--no-tags')
 
     args.push('--prune', '--no-recurse-submodules')
     if (options.showProgress) {
@@ -730,7 +728,19 @@ 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

@@ -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(
-      const refSpec = refHelper.getRefSpec(settings.ref, settings.commit)
+        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/input-helper.ts

@@ -71,7 +71,7 @@ export async function getInputs(): Promise<IGitSourceSettings> {
     }
   }
   // SHA?
-  else if (result.ref.match(/^[0-9a-fA-F]{40}$/)) {
+  else if (result.ref.match(/^(?:[0-9a-fA-F]{40}|[0-9a-fA-F]{64})$/)) {
     result.commit = result.ref
     result.ref = ''
   }

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 [
+    result.push(`+refs/heads/${ref}*:refs/remotes/origin/${ref}*`)
-      `+refs/heads/${ref}*:refs/remotes/origin/${ref}*`,
+    if (!fetchTags) {
-      `+refs/tags/${ref}*:refs/tags/${ref}*`
+      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 {
+  else if (upperRef.startsWith('REFS/TAGS/')) {
-    return [`+${ref}:${ref}`]
+    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
@@ -236,7 +258,9 @@ export async function checkCommitInfo(
     }
 
     // Extract details from message
-    const match = commitInfo.match(/Merge ([0-9a-f]{40}) into ([0-9a-f]{40})/)
+    const match = commitInfo.match(
+      /Merge ([0-9a-f]{40}|[0-9a-f]{64}) into ([0-9a-f]{40}|[0-9a-f]{64})/
+    )
     if (!match) {
       core.debug('Unexpected message format')
       return