Merge instead of rebasing upstream changes in `gclient sync` when --merge is given.

tests/gclient_scm_test.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 
 """Unit tests for gclient_scm.py."""
 
 # pylint: disable=E1103
 
 # Import before super_mox to keep valid references.
@@ skipping 734 matching lines @@
 commit refs/heads/origin
 mark :6
 author Alice <alice@example.com> 1253744424 -0700
 committer Alice <alice@example.com> 1253744424 -0700
 data 13
 Personalized
 from :3
 M 100644 :4 a
 M 100644 :5 b
 
+blob
+mark :7
+data 5
+Mooh
+
+commit refs/heads/feature
+mark :8
+author Bob <bob@example.com> 1390311986 -0000
+committer Bob <bob@example.com> 1390311986 -0000
+data 6
+Add C
+from :3
+M 100644 :7 c
+
 reset refs/heads/master
 from :3
 """
   def Options(self, *args, **kwargs):
     return self.OptionsObject(*args, **kwargs)
 
   @staticmethod
   def CreateGitRepo(git_import, path):
     """Do it for real."""
     try:
@@ skipping 195 matching lines @@
     expected_file_list = [join(self.base_path, x) for x in ['a', 'b']]
     scm = gclient_scm.CreateSCM(url=self.url, root_dir=self.root_dir,
                                 relpath=self.relpath)
     file_list = []
     scm.update(options, (), file_list)
     self.assertEquals(file_list, expected_file_list)
     self.assertEquals(scm.revinfo(options, (), None),
                       'a7142dc9f0009350b96a11f372b6ea658592aa95')
     sys.stdout.close()
 
+  def testUpdateMerge(self):
+    if not self.enabled:
+      return
+    options = self.Options()
+    options.merge = True
+    scm = gclient_scm.CreateSCM(url=self.url, root_dir=self.root_dir,
+                                relpath=self.relpath)
+    scm._Run(['checkout', '-q', 'feature'], options)
+    rev = scm.revinfo(options, (), None)
+    file_list = []
+    scm.update(options, (), file_list)
+    self.assertEquals(file_list, [join(self.base_path, x)
+                                  for x in ['a', 'b', 'c']])
+    # The actual commit that is created is unstable, so we verify its tree and
+    # parents instead.
+    self.assertEquals(scm._Capture(['show', '--format=%T', '-s']),
+                      'd2e35c10ac24d6c621e14a1fcadceb533155627d')

[iannucci, 2014/01/21 21:40:47]

Isn't this the same as `git rev-parse HEAD:`?

[Bernhard Bauer, 2014/01/21 23:03:54]

No, this is the tree (i.e. without the commit metadata).

[iannucci, 2014/01/21 23:23:29]

Right, hence the trailing colon :)

HEAD:path refers to tree object in a given commit, and : without the path is the
root tree object.

[Bernhard Bauer, 2014/01/22 15:59:50]

Ooh, that's neat! Done.

+    self.assertEquals(scm._Capture(['rev-parse', 'HEAD^1']), rev)
+    self.assertEquals(scm._Capture(['rev-parse', 'HEAD^2']),
+                      scm._Capture(['rev-parse', 'origin/master']))
+    sys.stdout.close()
+
+  def testUpdateRebase(self):
+    if not self.enabled:
+      return
+    options = self.Options()
+    scm = gclient_scm.CreateSCM(url=self.url, root_dir=self.root_dir,
+                                relpath=self.relpath)
+    scm._Run(['checkout', '-q', 'feature'], options)
+    rev = scm.revinfo(options, (), None)
+    file_list = []
+    # Fake a 'y' key press.
+    __builtin__.raw_input = lambda x: 'y'

[iannucci, 2014/01/21 21:40:47]

scary :). Does this automatically get set back to what it was? Can we use mox to
do this?

[Bernhard Bauer, 2014/01/21 23:03:54]

I have to admit, I stole this from updateConflict below... :) I'll try to make
it a bit less scary tomorrow.

[iannucci, 2014/01/21 23:23:29]

Heh, fair enough... as long as they're both the same hack... This is just not
threadsafe as-is (not that unittests parallelizes tests by default).

[Bernhard Bauer, 2014/01/22 15:59:50]

OK, I made it a method on |scm| which I can override.

+    scm.update(options, (), file_list)
+    self.assertEquals(file_list, [join(self.base_path, x)
+                                  for x in ['a', 'b', 'c']])
+    # The actual commit that is created is unstable, so we verify its tree and
+    # parent instead.
+    self.assertEquals(scm._Capture(['show', '--format=%T', '-s']),
+                      'd2e35c10ac24d6c621e14a1fcadceb533155627d')
+    self.assertEquals(scm._Capture(['rev-parse', 'HEAD^']),
+                      scm._Capture(['rev-parse', 'origin/master']))
+    sys.stdout.close()
+
   def testUpdateReset(self):
     if not self.enabled:
       return
     options = self.Options()
     options.reset = True
 
     dir_path = join(self.base_path, 'c')
     os.mkdir(dir_path)
     open(join(dir_path, 'nested'), 'w').writelines('new\n')
 
@@ skipping 225 matching lines @@
 
 if __name__ == '__main__':
   if '-v' in sys.argv:
     logging.basicConfig(
         level=logging.DEBUG,
         format='%(asctime).19s %(levelname)s %(filename)s:'
                '%(lineno)s %(message)s')
   unittest.main()
 
 # vim: ts=2:sw=2:tw=80:et: