Make git_map properly update merge base markers.

Make git_map properly update merge base markers.

R=agable@chromium.org
BUG=

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=270572

[agable, 2014-05-15 03:13:06]

lgtm

[iannucci, 2014-05-15 03:14:10]

The CQ bit was checked by iannucci@chromium.org

[commit-bot: I haz the power, 2014-05-15 03:14:32]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/iannucci@chromium.org/288123003/1

[commit-bot: I haz the power, 2014-05-15 03:16:11]

Change committed as 270572

[nodir, 2014-05-16 19:00:53]

This broke git-map

Traceback (most recent call last):
  File "/usr/local/google/home/nodir/cr/infra/depot_tools/git_map.py", line 112,
in <module>
    sys.exit(main())
  File "/usr/local/google/home/nodir/cr/infra/depot_tools/git_map.py", line 52,
in main
    merge_base_map = {b: get_or_create_merge_base(b) for b in all_branches}
  File "/usr/local/google/home/nodir/cr/infra/depot_tools/git_map.py", line 52,
in <dictcomp>
    merge_base_map = {b: get_or_create_merge_base(b) for b in all_branches}
  File "/usr/local/google/home/nodir/cr/infra/depot_tools/git_common.py", line
356, in get_or_create_merge_base
    actual_merge_base = run('merge-base', parent, branch)
  File "/usr/local/google/home/nodir/cr/infra/depot_tools/git_common.py", line
486, in run
    return run_with_stderr(*cmd, **kwargs)[0]
  File "/usr/local/google/home/nodir/cr/infra/depot_tools/git_common.py", line
518, in run_with_stderr
    proc = subprocess2.Popen(cmd, **kwargs)
  File "/usr/local/google/home/nodir/cr/infra/depot_tools/subprocess2.py", line
202, in __init__
    tmp_str = ' '.join(args)
TypeError: sequence item 4: expected string, NoneType found

--

in get_or_create_merge_base base and parent variables are None. branch is not
None.

[iannucci, 2014-05-16 19:02:24]

On 2014/05/16 19:00:53, nodir wrote:
> This broke git-map
> 
> Traceback (most recent call last):
>   File "/usr/local/google/home/nodir/cr/infra/depot_tools/git_map.py", line
112,
> in <module>
>     sys.exit(main())
>   File "/usr/local/google/home/nodir/cr/infra/depot_tools/git_map.py", line
52,
> in main
>     merge_base_map = {b: get_or_create_merge_base(b) for b in all_branches}
>   File "/usr/local/google/home/nodir/cr/infra/depot_tools/git_map.py", line
52,
> in <dictcomp>
>     merge_base_map = {b: get_or_create_merge_base(b) for b in all_branches}
>   File "/usr/local/google/home/nodir/cr/infra/depot_tools/git_common.py", line
> 356, in get_or_create_merge_base
>     actual_merge_base = run('merge-base', parent, branch)
>   File "/usr/local/google/home/nodir/cr/infra/depot_tools/git_common.py", line
> 486, in run
>     return run_with_stderr(*cmd, **kwargs)[0]
>   File "/usr/local/google/home/nodir/cr/infra/depot_tools/git_common.py", line
> 518, in run_with_stderr
>     proc = subprocess2.Popen(cmd, **kwargs)
>   File "/usr/local/google/home/nodir/cr/infra/depot_tools/subprocess2.py",
line
> 202, in __init__
>     tmp_str = ' '.join(args)
> TypeError: sequence item 4: expected string, NoneType found
> 
> --
> 
> in get_or_create_merge_base base and parent variables are None. branch is not
> None.

Fix is here, but is waiting for review:
https://chromiumcodereview.appspot.com/288323002/

I can split out the fix to map if it takes a little while to get review.