Use get_or_create_merge_base in git-cl-upload to correctly deal with rebased

Use get_or_create_merge_base in git-cl-upload to correctly deal with rebased
upstreams.

In the event that users are NOT using the enhanced tooling, this is equivalent
to `git merge-base "@{u}" HEAD`. In the event that they are, this will catch
the case where their parent branch got rebased, but this branch hasn't been
rebased on the parent yet.

R=agable@chromium.org, szager@chromium.org
BUG=

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=261601

[agable, 2014-04-03 22:52:24]

lgtm

[iannucci, 2014-04-03 22:52:54]

The CQ bit was checked by iannucci@chromium.org

[commit-bot: I haz the power, 2014-04-03 22:53:03]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/iannucci@chromium.org/224703002/1

[commit-bot: I haz the power, 2014-04-03 22:54:43]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-04-03 22:54:44]

Presubmit check for 224703002-1 failed and returned exit status 1.

Running presubmit commit checks ...
Checking out rietveld...
Running save-description-on-failure.sh
Running push-basic.sh
Running upstream.sh
Running submit-from-new-dir.sh
Running abandon.sh
Running submodule-merge-test.sh
Running upload-local-tracking-branch.sh
Running hooks.sh
Running post-dcommit-hook-test.sh
Running upload-stale.sh
Running patch.sh
Running basic.sh

** Presubmit ERRORS **
Pylint (94 files) (26.86s) failed
************* Module
/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_cl.py
R0201:554,2:Changelist.GetCommonAncestorWithUpstream: Method could be a function


tests/git_cl_test.py (0.46s) failed
...ERROR:root:@8  Expected: (['git', 'symbolic-ref', 'HEAD'],)   Actual:
(('git', 'rev-parse', '--abbrev-ref', 'HEAD'),)
FERROR:root:@8  Expected: (['git', 'symbolic-ref', 'HEAD'],)   Actual: (('git',
'rev-parse', '--abbrev-ref', 'HEAD'),)
FERROR:root:@8  Expected: (['git', 'symbolic-ref', 'HEAD'],)   Actual: (('git',
'rev-parse', '--abbrev-ref', 'HEAD'),)
FERROR:root:@8  Expected: (['git', 'symbolic-ref', 'HEAD'],)   Actual: (('git',
'rev-parse', '--abbrev-ref', 'HEAD'),)
FERROR:root:@8  Expected: (['git', 'symbolic-ref', 'HEAD'],)   Actual: (('git',
'rev-parse', '--abbrev-ref', 'HEAD'),)
FERROR:root:@8  Expected: (['git', 'symbolic-ref', 'HEAD'],)   Actual: (('git',
'rev-parse', '--abbrev-ref', 'HEAD'),)
FERROR:root:@8  Expected: (['git', 'symbolic-ref', 'HEAD'],)   Actual: (('git',
'rev-parse', '--abbrev-ref', 'HEAD'),)
FERROR:root:@8  Expected: (['git', 'symbolic-ref', 'HEAD'],)   Actual: (('git',
'rev-parse', '--abbrev-ref', 'HEAD'),)
FERROR:root:@8  Expected: (['git', 'symbolic-ref', 'HEAD'],)   Actual: (('git',
'rev-parse', '--abbrev-ref', 'HEAD'),)
FERROR:root:@8  Expected: (['git', 'symbolic-ref', 'HEAD'],)   Actual: (('git',
'rev-parse', '--abbrev-ref', 'HEAD'),)
FERROR:root:@8  Expected: (['git', 'symbolic-ref', 'HEAD'],)   Actual: (('git',
'rev-parse', '--abbrev-ref', 'HEAD'),)
FERROR:root:@8  Expected: (['git', 'symbolic-ref', 'HEAD'],)   Actual: (('git',
'rev-parse', '--abbrev-ref', 'HEAD'),)
FERROR:root:@8  Expected: (['git', 'symbolic-ref', 'HEAD'],)   Actual: (('git',
'rev-parse', '--abbrev-ref', 'HEAD'),)
F.
======================================================================
FAIL: test_gerrit_no_reviewer (__main__.TestGitCl)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests/git_cl_test.py", line 620, in test_gerrit_no_reviewer
    [])
  File "tests/git_cl_test.py", line 608, in _run_gerrit_upload_test
    git_cl.main(['upload'] + upload_args)
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_cl.py",
line 2536, in main
    return dispatcher.execute(OptionParser(), argv)
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/subcommand.py",
line 245, in execute
    return command(parser, args[1:])
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_cl.py",
line 1687, in CMDupload
    base_branch = cl.GetCommonAncestorWithUpstream()
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_cl.py",
line 555, in GetCommonAncestorWithUpstream
    return git_common.get_or_create_merge_base(git_common.current_branch())
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_common.py",
line 273, in current_branch
    return run('rev-parse', '--abbrev-ref', 'HEAD')
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_common.py",
line 465, in run
    return run_with_stderr(*cmd, **kwargs)[0]
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_common.py",
line 497, in run_with_stderr
    proc = subprocess2.Popen(cmd, **kwargs)
  File "tests/git_cl_test.py", line 107, in _mocked_call
    self.fail(msg)
AssertionError: @8  Expected: (['git', 'symbolic-ref', 'HEAD'],)   Actual:
(('git', 'rev-parse', '--abbrev-ref', 'HEAD'),)

======================================================================
FAIL: test_gerrit_reviewer_multiple (__main__.TestGitCl)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests/git_cl_test.py", line 633, in test_gerrit_reviewer_multiple
    ['reviewer@example.com', 'another@example.com'])
  File "tests/git_cl_test.py", line 608, in _run_gerrit_upload_test
    git_cl.main(['upload'] + upload_args)
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_cl.py",
line 2536, in main
    return dispatcher.execute(OptionParser(), argv)
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/subcommand.py",
line 245, in execute
    return command(parser, args[1:])
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_cl.py",
line 1687, in CMDupload
    base_branch = cl.GetCommonAncestorWithUpstream()
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_cl.py",
line 555, in GetCommonAncestorWithUpstream
    return git_common.get_or_create_merge_base(git_common.current_branch())
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_common.py",
line 273, in current_branch
    return run('rev-parse', '--abbrev-ref', 'HEAD')
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_common.py",
line 465, in run
    return run_with_stderr(*cmd, **kwargs)[0]
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_common.py",
line 497, in run_with_stderr
    proc = subprocess2.Popen(cmd, **kwargs)
  File "tests/git_cl_test.py", line 107, in _mocked_call
    self.fail(msg)
AssertionError: @8  Expected: (['git', 'symbolic-ref', 'HEAD'],)   Actual:
(('git', 'rev-parse', '--abbrev-ref', 'HEAD'),)

======================================================================
FAIL: test_gerrit_reviewers_cmd_line (__main__.TestGitCl)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests/git_cl_test.py", line 626, in test_gerrit_reviewers_cmd_line
    ['foo@example.com'])
  File "tests/git_cl_test.py", line 608, in _run_gerrit_upload_test
    git_cl.main(['upload'] + upload_args)
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_cl.py",
line 2536, in main
    return dispatcher.execute(OptionParser(), argv)
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/subcommand.py",
line 245, in execute
    return command(parser, args[1:])
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_cl.py",
line 1687, in CMDupload
    base_branch = cl.GetCommonAncestorWithUpstream()
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_cl.py",
line 555, in GetCommonAncestorWithUpstream
    return git_common.get_or_create_merge_base(git_common.current_branch())
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_common.py",
line 273, in current_branch
    return run('rev-parse', '--abbrev-ref', 'HEAD')
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_common.py",
line 465, in run
    return run_with_stderr(*cmd, **kwargs)[0]
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_common.py",
line 497, in run_with_stderr
    proc = subprocess2.Popen(cmd, **kwargs)
  File "tests/git_cl_test.py", line 107, in _mocked_call
    self.fail(msg)
AssertionError: @8  Expected: (['git', 'symbolic-ref', 'HEAD'],)   Actual:
(('git', 'rev-parse', '--abbrev-ref', 'HEAD'),)

======================================================================
FAIL: test_gerrit_upload_without_change_id (__main__.TestGitCl)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests/git_cl_test.py", line 614, in test_gerrit_upload_without_change_id
    [])
  File "tests/git_cl_test.py", line 608, in _run_gerrit_upload_test
    git_cl.main(['upload'] + upload_args)
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_cl.py",
line 2536, in main
    return dispatcher.execute(OptionParser(), argv)
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/subcommand.py",
line 245, in execute
    return command(parser, args[1:])
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_cl.py",
line 1687, in CMDupload
    base_branch = cl.GetCommonAncestorWithUpstream()
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_cl.py",
line 555, in GetCommonAncestorWithUpstream
    return git_common.get_or_create_merge_base(git_common.current_branch())
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_common.py",
line 273, in current_branch
    return run('rev-parse', '--abbrev-ref', 'HEAD')
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_common.py",
line 465, in run
    return run_with_stderr(*cmd, **kwargs)[0]
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_common.py",
line 497, in run_with_stderr
    proc = subprocess2.Popen(cmd, **kwargs)
  File "tests/git_cl_test.py", line 107, in _mocked_call
    self.fail(msg)
AssertionError: @8  Expected: (['git', 'symbolic-ref', 'HEAD'],)   Actual:
(('git', 'rev-parse', '--abbrev-ref', 'HEAD'),)

======================================================================
FAIL: test_keep_find_copies (__main__.TestGitCl)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests/git_cl_test.py", line 434, in test_keep_find_copies
    [])
  File "tests/git_cl_test.py", line 410, in _run_reviewer_test
    git_cl.main(['upload'] + upload_args)
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_cl.py",
line 2536, in main
    return dispatcher.execute(OptionParser(), argv)
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/subcommand.py",
line 245, in execute
    return command(parser, args[1:])
  File "/b/infra_internal/commit_queue/workdir/tools/depot_tools/git_cl.p…
(message too large)

[iannucci, 2014-04-03 22:55:49]

mox strikes again :(

[agable, 2014-04-04 00:21:15]

On 2014/04/03 22:55:49, iannucci wrote:
> mox strikes again :(

why did HEADs turn into masters?

[iannucci, 2014-04-04 00:21:50]

fixed the tests by mocking git_common.get_or_create_merge_base. I think this is
justified since get_or_create_merge_base has its own tests
(tests/git_common_test.py).

[iannucci, 2014-04-04 00:24:08]

On 2014/04/04 00:21:15, agable wrote:
> On 2014/04/03 22:55:49, iannucci wrote:
> > mox strikes again :(
> 
> why did HEADs turn into masters?

Before it would take base(HEAD, @{u}), but since the merge base markers are
keyed on branchname, I opted to use base(branch, @{u}). In practice this should
be fine because you can't use git cl upload on a detached HEAD anyway:

➜  depot_tools git:(0a42737) git cl upload
fatal: ref HEAD is not a symbolic ref
Command "git symbolic-ref HEAD" failed.

The reason the second one is 'master' and not 'origin/master' is because of test
mockery.

[agable, 2014-04-04 00:26:41]

lgtm

[iannucci, 2014-04-04 00:30:00]

The CQ bit was checked by iannucci@chromium.org

[commit-bot: I haz the power, 2014-04-04 00:30:09]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/iannucci@chromium.org/224703002/20001

[commit-bot: I haz the power, 2014-04-04 00:32:00]

Change committed as 261601