Merge pull request swiftlang#33075 from nate-chandler/update-checkout/fallback-to-checkout-revision

[Update Checkout] Fall back to revision if branch checkout fails.

Author: nate-chandler

utils/update_checkout/tests/scheme_mock.py

@@ -119,6 +119,8 @@ def setup_mock_remote(base_dir):
     with open(get_config_path(base_dir), 'w') as f:
         json.dump(base_config, f)
 
+    return (LOCAL_PATH, REMOTE_PATH)
+
 
 BASEDIR_ENV_VAR = 'UPDATECHECKOUT_TEST_WORKSPACE_DIR'
 CURRENT_FILE_DIR = os.path.dirname(os.path.abspath(__file__))
@@ -147,7 +149,7 @@ def __init__(self, *args, **kwargs):
 
     def setUp(self):
         create_dir(self.source_root)
-        setup_mock_remote(self.workspace)
+        (self.local_path, self.remote_path) = setup_mock_remote(self.workspace)
 
     def tearDown(self):
         teardown_mock_remote(self.workspace)

utils/update_checkout/tests/test_update_worktree.py

@@ -0,0 +1,65 @@
+# ===--- test_clone.py ----------------------------------------------------===#
+#
+# This source file is part of the Swift.org open source project
+#
+# Copyright (c) 2014 - 2020 Apple Inc. and the Swift project authors
+# Licensed under Apache License v2.0 with Runtime Library Exception
+#
+# See https:#swift.org/LICENSE.txt for license information
+# See https:#swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+#
+# ===----------------------------------------------------------------------===#
+
+import os
+
+from scheme_mock import call_quietly
+
+from . import scheme_mock
+
+WORKTREE_NAME = "feature"
+
+
+def path_for_worktree(workspace_path, worktree_name):
+    return os.path.join(workspace_path, worktree_name)
+
+
+def setup_worktree(workspace_path, local_path, worktree_name):
+    worktree_path = path_for_worktree(workspace_path, worktree_name)
+    os.makedirs(worktree_path)
+    for project in os.listdir(local_path):
+        local_project_path = os.path.join(local_path, project)
+        worktree_project_path = os.path.join(worktree_path, project)
+        call_quietly(['git', 
+                      '-C', local_project_path, 
+                      'worktree', 'add', worktree_project_path])
+
+
+def teardown_worktree(workspace_path, local_path, worktree_name):
+    worktree_path = path_for_worktree(workspace_path, worktree_name)
+    for project in os.listdir(local_path):
+        local_project_path = os.path.join(local_path, project)
+        worktree_project_path = os.path.join(worktree_path, project)
+        call_quietly(['git', 
+                      '-C', local_project_path, 
+                      'worktree', 'remove', worktree_project_path])
+
+
+class WorktreeTestCase(scheme_mock.SchemeMockTestCase):
+
+    def __init__(self, *args, **kwargs):
+        super(WorktreeTestCase, self).__init__(*args, **kwargs)
+
+    def test_worktree(self):
+        self.call([self.update_checkout_path,
+                   '--config', self.config_path,
+                   '--source-root', self.worktree_path,
+                   '--scheme', 'master'])
+
+    def setUp(self):
+        super(WorktreeTestCase, self).setUp()
+        self.worktree_path = os.path.join(self.workspace, WORKTREE_NAME)
+        setup_worktree(self.workspace, self.local_path, WORKTREE_NAME)
+
+    def tearDown(self):
+        teardown_worktree(self.workspace, self.local_path, WORKTREE_NAME)
+        super(WorktreeTestCase, self).tearDown()

utils/update_checkout/update_checkout/update_checkout.py

@@ -159,7 +159,15 @@ def update_single_repository(pool_args):
             if checkout_target:
                 shell.run(['git', 'status', '--porcelain', '-uno'],
                           echo=False)
-                shell.run(['git', 'checkout', checkout_target], echo=True)
+                try:
+                    shell.run(['git', 'checkout', checkout_target], echo=True)
+                except Exception as originalException:
+                    try:
+                        result = shell.run(['git', 'rev-parse', checkout_target])
+                        revision = result[0].strip()
+                        shell.run(['git', 'checkout', revision], echo=True)
+                    except Exception as e:
+                        raise originalException
 
             # It's important that we checkout, fetch, and rebase, in order.
             # .git/FETCH_HEAD updates the not-for-merge attributes based on