Revert "git-cl: Fix format --dry-run not working with --full."

This reverts commit fc132e61db.

Reason for revert: Causes all presubmit checks to return dirty
format because of a non-zero diff output.

Original change's description:
> git-cl: Fix format --dry-run not working with --full.
> 
> The --full option would skip setting the return value of the format
> command when used with --dry-run. This in turn would cause the
> presubmit check to always pass when --full was enabled in a repo by
> default.
> 
> Was discovered in the ANGLE repository.
> 
> Bug: angleproject:4241
> Change-Id: Ie6cb423a6818c1e26781d77938a0dd22c02b4c16
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1987835
> Commit-Queue: Jamie Madill <jmadill@chromium.org>
> Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>
> Auto-Submit: Jamie Madill <jmadill@chromium.org>

TBR=ehmaldonado@chromium.org,jmadill@chromium.org

Change-Id: I0a4c51117ab20606f6dbb1f7a3ba40f87da1e939
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: angleproject:4241
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1993907
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>

git_cl.py

@@ -5117,56 +5117,6 @@ def BuildGitDiffCmd(diff_type, upstream_commit, args, allow_prefix=False):
   return diff_cmd
 
 
-def _RunClangFormatDiff(opts, clang_diff_files, top_dir, upstream_commit):
-  """Runs clang-format-diff and sets a return value if necessary."""
-
-  if not clang_diff_files:
-    return 0
-
-  # Set to 2 to signal to CheckPatchFormatted() that this patch isn't
-  # formatted. This is used to block during the presubmit.
-  return_value = 0
-
-  # Locate the clang-format binary in the checkout
-  try:
-    clang_format_tool = clang_format.FindClangFormatToolInChromiumTree()
-  except clang_format.NotFoundError as e:
-    DieWithError(e)
-
-  if opts.full or settings.GetFormatFullByDefault():
-    cmd = [clang_format_tool]
-    if not opts.dry_run and not opts.diff:
-      cmd.append('-i')
-    stdout = RunCommand(cmd + clang_diff_files, cwd=top_dir)
-    if opts.diff:
-      sys.stdout.write(stdout)
-    if opts.dry_run and len(stdout) > 0:
-      return_value = 2
-  else:
-    env = os.environ.copy()
-    env['PATH'] = str(os.path.dirname(clang_format_tool))
-    try:
-      script = clang_format.FindClangFormatScriptInChromiumTree(
-          'clang-format-diff.py')
-    except clang_format.NotFoundError as e:
-      DieWithError(e)
-
-    cmd = [sys.executable, script, '-p0']
-    if not opts.dry_run and not opts.diff:
-      cmd.append('-i')
-
-    diff_cmd = BuildGitDiffCmd('-U0', upstream_commit, clang_diff_files)
-    diff_output = RunGit(diff_cmd)
-
-    stdout = RunCommand(cmd, stdin=diff_output, cwd=top_dir, env=env)
-    if opts.diff:
-      sys.stdout.write(stdout)
-    if opts.dry_run and len(stdout) > 0:
-      return_value = 2
-
-  return return_value
-
-
 def MatchingFileType(file_name, extensions):
   """Returns True if the file name ends with one of the given extensions."""
   return bool([ext for ext in extensions if file_name.lower().endswith(ext)])
@@ -5263,8 +5213,45 @@ def CMDformat(parser, args):
   top_dir = os.path.normpath(
       RunGit(["rev-parse", "--show-toplevel"]).rstrip('\n'))
 
-  return_value = _RunClangFormatDiff(opts, clang_diff_files, top_dir,
-                                     upstream_commit)
+  # Set to 2 to signal to CheckPatchFormatted() that this patch isn't
+  # formatted. This is used to block during the presubmit.
+  return_value = 0
+
+  if clang_diff_files:
+    # Locate the clang-format binary in the checkout
+    try:
+      clang_format_tool = clang_format.FindClangFormatToolInChromiumTree()
+    except clang_format.NotFoundError as e:
+      DieWithError(e)
+
+    if opts.full or settings.GetFormatFullByDefault():
+      cmd = [clang_format_tool]
+      if not opts.dry_run and not opts.diff:
+        cmd.append('-i')
+      stdout = RunCommand(cmd + clang_diff_files, cwd=top_dir)
+      if opts.diff:
+        sys.stdout.write(stdout)
+    else:
+      env = os.environ.copy()
+      env['PATH'] = str(os.path.dirname(clang_format_tool))
+      try:
+        script = clang_format.FindClangFormatScriptInChromiumTree(
+            'clang-format-diff.py')
+      except clang_format.NotFoundError as e:
+        DieWithError(e)
+
+      cmd = [sys.executable, script, '-p0']
+      if not opts.dry_run and not opts.diff:
+        cmd.append('-i')
+
+      diff_cmd = BuildGitDiffCmd('-U0', upstream_commit, clang_diff_files)
+      diff_output = RunGit(diff_cmd)
+
+      stdout = RunCommand(cmd, stdin=diff_output, cwd=top_dir, env=env)
+      if opts.diff:
+        sys.stdout.write(stdout)
+      if opts.dry_run and len(stdout) > 0:
+        return_value = 2
 
   # Similar code to above, but using yapf on .py files rather than clang-format
   # on C/C++ files
@@ -5349,7 +5336,7 @@ def CMDformat(parser, args):
       stdout = RunCommand(command, cwd=top_dir)
       if opts.dry_run and stdout:
         return_value = 2
-    except dart_format.NotFoundError:
+    except dart_format.NotFoundError as e:
       print('Warning: Unable to check Dart code formatting. Dart SDK not '
             'found in this checkout. Files in other languages are still '
             'formatted.')

tests/git_cl_test.py

@@ -32,7 +32,6 @@ import metrics
 # We have to disable monitoring before importing git_cl.
 metrics.DISABLE_METRICS_COLLECTION = True
 
-import clang_format
 import gerrit_util
 import git_cl
 import git_common
@@ -3442,52 +3441,20 @@ class CMDFormatTestCase(TestCase):
 
   def setUp(self):
     super(CMDFormatTestCase, self).setUp()
-    mock.patch('git_cl.RunCommand').start()
-    mock.patch('clang_format.FindClangFormatToolInChromiumTree').start()
-    mock.patch('clang_format.FindClangFormatScriptInChromiumTree').start()
-    mock.patch('git_cl.settings').start()
     self._top_dir = tempfile.mkdtemp()
-    self.addCleanup(mock.patch.stopall)
 
   def tearDown(self):
     shutil.rmtree(self._top_dir)
     super(CMDFormatTestCase, self).tearDown()
 
-  def _make_temp_file(self, fname, contents):
-    with open(os.path.join(self._top_dir, fname), 'w') as tf:
-      tf.write('\n'.join(contents))
-
   def _make_yapfignore(self, contents):
-    self._make_temp_file('.yapfignore', contents)
+    with open(os.path.join(self._top_dir, '.yapfignore'), 'w') as yapfignore:
+      yapfignore.write('\n'.join(contents))
 
   def _check_yapf_filtering(self, files, expected):
     self.assertEqual(expected, git_cl._FilterYapfIgnoredFiles(
         files, git_cl._GetYapfIgnorePatterns(self._top_dir)))
 
-  def testClangFormatDiff(self):
-    git_cl.RunCommand.return_value = 'error'
-    git_cl.settings.GetFormatFullByDefault.return_value = False
-    return_value = git_cl._RunClangFormatDiff(
-        mock.Mock(full=True, dry_run=True, diff=False), ['.'], self._top_dir,
-        'HEAD')
-    self.assertEqual(2, return_value)
-    return_value = git_cl._RunClangFormatDiff(
-        mock.Mock(full=False, dry_run=True, diff=False), ['.'], self._top_dir,
-        'HEAD')
-    self.assertEqual(2, return_value)
-
-  def testClangFormatNoDiff(self):
-    git_cl.RunCommand.return_value = ''
-    git_cl.settings.GetFormatFullByDefault.return_value = False
-    return_value = git_cl._RunClangFormatDiff(
-        mock.Mock(full=True, dry_run=True, diff=False), ['.'], self._top_dir,
-        'HEAD')
-    self.assertEqual(0, return_value)
-    return_value = git_cl._RunClangFormatDiff(
-        mock.Mock(full=False, dry_run=True, diff=False), ['.'], self._top_dir,
-        'HEAD')
-    self.assertEqual(0, return_value)
-
   def testYapfignoreExplicit(self):
     self._make_yapfignore(['foo/bar.py', 'foo/bar/baz.py'])
     files = [