Fix git cl on windows for git-numberer repos.

Git cl decides if git-numberer is enabled on a repository by writing
Gerrit's project.config from refs/meta/config into a tempfile, which is
then queried using `git config -f tempfile --get ...`.  The file itself
is only flushed, but not closed after writing because Python's
tempfile.NamedTemporaryFile is deleted on closing. This worked fine on
Linix/Mac, but not on Windows, where `git config` apparently doesn't see
file or its contents.

This CL rewrites the above using yet another contexmanager temp
directory into which a file is written and closed before git config is
ran.

R=machenbach@chromium.org,grt@chromium.org
BUG=683202

Change-Id: I7974d66b1b2b0478ab4b6f7ac04e547a4981c46c
Reviewed-on: https://chromium-review.googlesource.com/430719
Commit-Queue: Andrii Shyshkalov <tandrii@chromium.org>
Reviewed-by: Vadim Shtayura <vadimsh@chromium.org>

gclient_utils.py

@@ -5,6 +5,7 @@
 """Generic utils."""
 
 import codecs
+import contextlib
 import cStringIO
 import datetime
 import logging
@@ -143,6 +144,16 @@ def FileWrite(filename, content, mode='w'):
     f.write(content)
 
 
+@contextlib.contextmanager
+def temporary_directory(**kwargs):
+  tdir = tempfile.mkdtemp(**kwargs)
+  try:
+    yield tdir
+  finally:
+    if tdir:
+      rmtree(tdir)
+
+
 def safe_rename(old, new):
   """Renames a file reliably.
 

git_cl.py

@@ -23,7 +23,6 @@ import os
 import re
 import stat
 import sys
-import tempfile
 import textwrap
 import traceback
 import urllib
@@ -973,20 +972,19 @@ class _GitNumbererState(object):
       return False
     # Gerrit's project.config is really a git config file.
     # So, parse it as such.
-    with tempfile.NamedTemporaryFile(prefix='git_cl_proj_config') as f:
-      f.write(project_config_data)
-      # Make sure OS sees this, but don't close the file just yet,
-      # as NamedTemporaryFile deletes it on closing.
-      f.flush()
+    with gclient_utils.temporary_directory() as tempdir:
+      project_config_file = os.path.join(tempdir, 'project.config')
+      gclient_utils.FileWrite(project_config_file, project_config_data)
 
       def get_opts(x):
         code, out = cls._run_git_with_code(
-            ['config', '-f', f.name, '--get-all',
+            ['config', '-f', project_config_file, '--get-all',
              'plugin.git-numberer.validate-%s-refglob' % x])
         if code == 0:
           return out.strip().splitlines()
         return []
       enabled, disabled = map(get_opts, ['enabled', 'disabled'])
+
     logging.info('validator config enabled %s disabled %s refglobs for '
                  '(this ref: %s)', enabled, disabled, ref)
 

tests/git_cl_test.py

@@ -1102,13 +1102,15 @@ class TestGitCl(TestCase):
     self.assertEqual(res.should_add_git_number, False)
 
   def test_GitNumbererState_valid_configs(self):
-    class NamedTempFileStab(StringIO.StringIO):
-      @classmethod
+    with git_cl.gclient_utils.temporary_directory() as tempdir:
       @contextlib.contextmanager
-      def create(cls, *_, **__):
-        yield cls()
-      name = 'tempfile'
-    self.mock(git_cl.tempfile, 'NamedTemporaryFile', NamedTempFileStab.create)
+      def fake_temporary_directory(**kwargs):
+        yield tempdir
+      self.mock(git_cl.gclient_utils, 'temporary_directory',
+                fake_temporary_directory)
+      self._test_GitNumbererState_valid_configs_inner(tempdir)
+
+  def _test_GitNumbererState_valid_configs_inner(self, tempdir):
     self.calls = [
         ((['git', 'fetch', 'https://chromium.googlesource.com/chromium/src',
            '+refs/meta/config:refs/git_cl/meta/config',
@@ -1130,12 +1132,12 @@ class TestGitCl(TestCase):
             validate-disabled-refglob = refs/heads/disabled
             validate-disabled-refglob = refs/branch-heads/*
          '''),
-        ((['git', 'config', '-f', 'tempfile', '--get-all',
-           'plugin.git-numberer.validate-enabled-refglob'],),
+        ((['git', 'config', '-f', os.path.join(tempdir, 'project.config') ,
+           '--get-all', 'plugin.git-numberer.validate-enabled-refglob'],),
          'refs/else/*\n'
          'refs/heads/*\n'),
-        ((['git', 'config', '-f', 'tempfile', '--get-all',
-           'plugin.git-numberer.validate-disabled-refglob'],),
+        ((['git', 'config', '-f', os.path.join(tempdir, 'project.config') ,
+           '--get-all', 'plugin.git-numberer.validate-disabled-refglob'],),
          'refs/heads/disabled\n'
          'refs/branch-heads/*\n'),
     ] * 4  # 4 tests below have exactly same IO.