gclient_scm: Decode Git output centrally for better Python 3 support

This avoids the need to do the decoding everywhere separately.
Also a small fix for filter() no longer returning a list on Py3.

The scripts still work with Python 2.
There are no intended behaviour changes.

Bug: 942522
Change-Id: Id0f5153011b2ef1b64394359087864cd9434e45e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1595685
Commit-Queue: Dirk Pranke <dpranke@chromium.org>
Auto-Submit: Raul Tambre <raul@tambre.ee>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>

gclient_scm.py

@@ -256,9 +256,10 @@ class GitWrapper(SCMWrapper):
   def _GetDiffFilenames(self, base):
     """Returns the names of files modified since base."""
     return self._Capture(
-      # Filter to remove base if it is None.
-      filter(bool, ['-c', 'core.quotePath=false', 'diff', '--name-only', base])
-    ).split()
+        # Filter to remove base if it is None.
+        list(filter(bool, ['-c', 'core.quotePath=false', 'diff', '--name-only',
+                           base])
+        )).split()
 
   def diff(self, options, _args, _file_list):
     _, revision = gclient_utils.SplitUrlRevision(self.url)
@@ -630,7 +631,7 @@ class GitWrapper(SCMWrapper):
     # Skip url auto-correction if remote.origin.gclient-auto-fix-url is set.
     # This allows devs to use experimental repos which have a different url
     # but whose branch(s) are the same as official repos.
-    if (current_url.rstrip(b'/') != url.rstrip('/') and url != 'git://foo' and
+    if (current_url.rstrip('/') != url.rstrip('/') and url != 'git://foo' and
         subprocess2.capture(
             ['git', 'config', 'remote.%s.gclient-auto-fix-url' % self.remote],
             cwd=self.checkout_path).strip() != 'False'):
@@ -1306,7 +1307,8 @@ class GitWrapper(SCMWrapper):
     kwargs.setdefault('stderr', subprocess2.PIPE)
     strip = kwargs.pop('strip', True)
     env = scm.GIT.ApplyEnvVars(kwargs)
-    ret = subprocess2.check_output(['git'] + args, env=env, **kwargs)
+    ret = subprocess2.check_output(
+        ['git'] + args, env=env, **kwargs).decode('utf-8')
     if strip:
       ret = ret.strip()
     return ret

scm.py

@@ -117,8 +117,8 @@ class GIT(object):
   def Capture(args, cwd, strip_out=True, **kwargs):
     env = GIT.ApplyEnvVars(kwargs)
     output = subprocess2.check_output(
-        ['git'] + args,
-        cwd=cwd, stderr=subprocess2.PIPE, env=env, **kwargs)
+        ['git'] + args, cwd=cwd, stderr=subprocess2.PIPE, env=env,
+        **kwargs).decode('utf-8')
     return output.strip() if strip_out else output
 
   @staticmethod
@@ -388,7 +388,7 @@ class GIT(object):
     """Asserts git's version is at least min_version."""
     if cls.current_version is None:
       current_version = cls.Capture(['--version'], '.')
-      matched = re.search(r'version ([0-9\.]+)', current_version.decode())
+      matched = re.search(r'version ([0-9\.]+)', current_version)
       cls.current_version = matched.group(1)
     current_version_list = list(map(only_int, cls.current_version.split('.')))
     for min_ver in map(int, min_version.split('.')):

testing_support/fake_repos.py

 #!/usr/bin/env python
+# -*- coding: utf-8 -*-
 # Copyright (c) 2011 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
@@ -140,7 +141,7 @@ class FakeReposBase(object):
   # Hostname
   NB_GIT_REPOS = 1
   USERS = [
-      ('user1@example.com', 'foo'),
+      ('user1@example.com', 'foo Fuß'),
       ('user2@example.com', 'bar'),
   ]