Add --allow-conflicts option to git cl cherry-pick

This CL adds a new --allow-conflicts flag to the `git cl cherry-pick`
command. This allows users to create cherry-pick CLs on Gerrit even if
they result in merge conflicts. The created CL will be in a WIP state,
allowing the user to resolve conflicts in the Gerrit UI or locally.

Additionally, this CL:
- Updates `CMDcherry_pick` to print a regex-friendly warning if the
  created cherry-pick contains conflicts:
  "Warning: Change <URL> contains merge conflicts"
  (needed for the Chrome Cherry Picker)
- Fixes some existing test failures in `gerrit_util_test.py` related to
  authentication mocking in the current environment.
- Adds unit tests for the new flag in both `git_cl_test.py`
  and `gerrit_util_test.py`.

Bug: 439992429
Change-Id: I306e21329688a31a63c9996f1405f5ef5ad07108
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/7319362
Reviewed-by: Gavin Mak <gavinmak@google.com>
Commit-Queue: Gennady Tsitovich <gtsitovich@google.com>

gerrit_util.py

@@ -1702,7 +1702,8 @@ def CherryPick(host,
                destination,
                revision='current',
                message=None,
-               base=None):
+               base=None,
+               allow_conflicts=False):
     """Create a cherry-pick commit from the given change, onto the given
     destination.
     """
@@ -1712,6 +1713,8 @@ def CherryPick(host,
         body['message'] = message
     if base:
         body['base'] = base
+    if allow_conflicts:
+        body['allow_conflicts'] = True
     conn = CreateHttpConn(host, path, reqtype='POST', body=body)
 
     # If a cherry pick fails due to a merge conflict, Gerrit returns 409.

git_cl.py

@@ -4861,6 +4861,11 @@ def CMDcherry_pick(parser, args):
                       default=None,
                       help='Gerrit host, needed in case the command is used in '
                       'a non-git environment.')
+    parser.add_option('--allow-conflicts',
+                      action='store_true',
+                      default=False,
+                      help='If true, the cherry-pick will be created even if '
+                      'there are conflicts.')
     options, args = parser.parse_args(args)
 
     host = None
@@ -4946,11 +4951,13 @@ def CMDcherry_pick(parser, args):
               f'{original_commit_hash} ("{orig_subj_line}") onto base '
               f'{parent_commit_hash or options.branch + " tip"}...')
         try:
-            new_change_info = gerrit_util.CherryPick(host,
+            new_change_info = gerrit_util.CherryPick(
+                host,
                 change_id,
                 options.branch,
                 message=message,
-                                                     base=parent_commit_hash)
+                base=parent_commit_hash,
+                allow_conflicts=options.allow_conflicts)
         except gerrit_util.GerritError as e:
             print(f'Failed to create cherry pick "{orig_subj_line}": {e}. '
                   'Please resolve any merge conflicts.')
@@ -4961,6 +4968,8 @@ def CMDcherry_pick(parser, args):
         new_change_num = new_change_info['_number']
         new_change_url = gerrit_util.GetChangePageUrl(host, new_change_num)
         print(f'Created cherry pick of "{orig_subj_line}": {new_change_url}')
+        if new_change_info.get('contains_git_conflicts'):
+            print(f'Warning: Change {new_change_url} contains merge conflicts')
         parent_change_num = new_change_num
 
     return 0

tests/gerrit_util_test.py

@@ -349,10 +349,12 @@ class GitCredsAuthenticatorTest(unittest.TestCase):
 
     @mock.patch('gerrit_util.GitCredsAuthenticator._is_usehttppath_set',
                 return_value=True)
+    @mock.patch('gerrit_util.GitCredsAuthenticator.gerrit_account_exists',
+                return_value=True)
     @mock.patch('auth.GerritAuthenticator.get_authorization_header',
                 return_value="BearerReAuth xyz")
     def testEnsureAuthenticatedWithReAuth(self, mock_get_authorization_header,
-                                          _):
+                                          _exists, _set):
         reauth_context = auth.ReAuthContext(
             host="chromium-review.googlesource.com", project="chromium/src")
         gerrit_host = "chromium-review.googlesource.com"
@@ -369,7 +371,12 @@ class GitCredsAuthenticatorTest(unittest.TestCase):
 
     @mock.patch('gerrit_util.GitCredsAuthenticator._is_usehttppath_set',
                 return_value=False)
-    def testEnsureAuthenticatedMissingUseHttpPath(self, _):
+    @mock.patch('gerrit_util.GitCredsAuthenticator.gerrit_account_exists',
+                return_value=True)
+    @mock.patch('auth.GerritAuthenticator.get_authorization_header',
+                return_value="BearerReAuth xyz")
+    def testEnsureAuthenticatedMissingUseHttpPath(self, mock_get_header,
+                                                  _exists, _set):
         reauth_context = auth.ReAuthContext(
             host="chromium-review.googlesource.com", project="chromium/src")
         gerrit_host = "chromium-review.googlesource.com"
@@ -385,7 +392,9 @@ class GitCredsAuthenticatorTest(unittest.TestCase):
 
     @mock.patch('auth.GerritAuthenticator.get_authorization_header',
                 side_effect=auth.GitReAuthRequiredError())
-    def testEnsureAuthenticatedMissingReAuth(self,
+    @mock.patch('gerrit_util.GitCredsAuthenticator.gerrit_account_exists',
+                return_value=True)
+    def testEnsureAuthenticatedMissingReAuth(self, _exists,
                                              mock_get_authorization_header):
         gerrit_host = "chromium-review.googlesource.com"
         git_host = "chromium.googlesource.com"
@@ -832,6 +841,23 @@ class GerritUtilTest(unittest.TestCase):
         httpConnKwargs = mockCreateHttpConn.call_args[1]
         self.assertIsNone(httpConnKwargs.get('reauth_context', None))
 
+    @mock.patch('gerrit_util.CreateHttpConn')
+    @mock.patch('gerrit_util.ReadHttpJsonResponse')
+    def testCherryPickWithConflicts(self, mockJsonResponse, mockCreateHttpConn):
+        mockJsonResponse.return_value = {'_number': 1}
+        gerrit_util.CherryPick('host',
+                               'change',
+                               'destination',
+                               allow_conflicts=True)
+        mockCreateHttpConn.assert_called_once_with(
+            'host',
+            'changes/change/revisions/current/cherrypick',
+            reqtype='POST',
+            body={
+                'destination': 'destination',
+                'allow_conflicts': True
+            })
+
 class SSOAuthenticatorTest(unittest.TestCase):
 
     @classmethod

tests/git_cl_test.py

@@ -5649,9 +5649,6 @@ class CMDLintTestCase(CMDTestCaseBase):
 
 class CMDCherryPickTestCase(CMDTestCaseBase):
 
-    def setUp(self):
-        super(CMDTestCaseBase, self).setUp()
-
     def testCreateCommitMessage(self):
         orig_message = """Foo the bar
 
@@ -5700,6 +5697,72 @@ Change-Id: I25699146b24c7ad8776f17775f489b9d41499595
         self.assertEqual(git_cl._create_commit_message(orig_message, bug),
                          expected_message)
 
+    @mock.patch('gerrit_util.QueryChanges')
+    @mock.patch('gerrit_util.CherryPick')
+    @mock.patch('gerrit_util.GetChangePageUrl', return_value='url')
+    def testCherryPick_AllowConflicts(self, _mockGetUrl, mockCherryPick,
+                                      mockQueryChanges):
+        mockQueryChanges.return_value = [{
+            'id': 'change_id',
+            'revisions': {
+                'abc': {
+                    'commit': {
+                        'message': 'msg'
+                    }
+                }
+            }
+        }]
+        mockCherryPick.return_value = {
+            '_number': 123,
+            'contains_git_conflicts': True
+        }
+
+        self.assertEqual(
+            0,
+            git_cl.main(
+                ['cherry-pick', '--branch', 'main', 'abc',
+                 '--allow-conflicts']))
+
+        expected_message = 'Cherry pick "msg"\n\nOriginal change\'s description:\n> msg\n\n'
+        mockCherryPick.assert_called_once_with(
+            'chromium-review.googlesource.com',
+            'change_id',
+            'main',
+            message=expected_message,
+            base=None,
+            allow_conflicts=True)
+        self.assertIn('Warning: Change url contains merge conflicts',
+                      sys.stdout.getvalue())
+
+    @mock.patch('gerrit_util.QueryChanges')
+    @mock.patch('gerrit_util.CherryPick')
+    @mock.patch('gerrit_util.GetChangePageUrl', return_value='url')
+    def testCherryPick_NoAllowConflicts(self, _mockGetUrl, mockCherryPick,
+                                        mockQueryChanges):
+        mockQueryChanges.return_value = [{
+            'id': 'change_id',
+            'revisions': {
+                'abc': {
+                    'commit': {
+                        'message': 'msg'
+                    }
+                }
+            }
+        }]
+        mockCherryPick.return_value = {'_number': 123}
+
+        self.assertEqual(
+            0, git_cl.main(['cherry-pick', '--branch', 'main', 'abc']))
+
+        expected_message = 'Cherry pick "msg"\n\nOriginal change\'s description:\n> msg\n\n'
+        mockCherryPick.assert_called_once_with(
+            'chromium-review.googlesource.com',
+            'change_id',
+            'main',
+            message=expected_message,
+            base=None,
+            allow_conflicts=False)
+
 
 @unittest.skipIf(gclient_utils.IsEnvCog(),
                  'not supported in non-git environment')