Refactor the way that git executables are launched in depot tools.

Refactor the way that git executables are launched in depot tools.

This introduces python_git_runner.sh, and makes git-cl, git-cache, git-number,
and git-try use it.

R=agable@chromium.org, szager@chromium.org
BUG=261738
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=256131

[agable, 2014-03-06 18:02:19]

LGTM

https://codereview.chromium.org/188383002/diff/1/git-cl
File git-cl (right):

https://codereview.chromium.org/188383002/diff/1/git-cl#newcode7
git-cl:7: # Copyright (C) 2008 Evan Martin <martine@danga.com>
Does this copyright notice belong in this file? Or should it just be in the
python file? I don't know.

https://codereview.chromium.org/188383002/diff/1/gitscripts/git_cl.py
File gitscripts/git_cl.py (right):

https://codereview.chromium.org/188383002/diff/1/gitscripts/git_cl.py#newcode44
gitscripts/git_cl.py:44: import owners_finder
Just confirming that all these rely on depot_tools being in pythonpath, so none
of these imports break.

[iannucci, 2014-03-07 11:28:17]

So, I moved everything back. There's just too many interdependencies on git_cl.
It was a nice idea. We can do it later.

https://codereview.chromium.org/188383002/diff/1/git-cl
File git-cl (right):

https://codereview.chromium.org/188383002/diff/1/git-cl#newcode7
git-cl:7: # Copyright (C) 2008 Evan Martin <martine@danga.com>
On 2014/03/06 18:02:20, agable wrote:
> Does this copyright notice belong in this file? Or should it just be in the
> python file? I don't know.

¯\_(ツ)_/¯

[iannucci, 2014-03-10 01:54:48]

OK, one more TALP. After messing with windows for a while, I discovered that
'which' works to find the runner script, as long at depot_tools is in the PATH.
This should be an OK assumption, because anyone who is invoking git-commands
directly (without them in the path) is "Doing It Rong™".

This latest version totally works on windows as well as mac (and therefore, I'm
assuming it works on linux). It is also more readable!

[iannucci, 2014-03-10 18:27:21]

On 2014/03/10 01:54:48, iannucci wrote:
> OK, one more TALP. After messing with windows for a while, I discovered that
> 'which' works to find the runner script, as long at depot_tools is in the
PATH.
> This should be an OK assumption, because anyone who is invoking git-commands
> directly (without them in the path) is "Doing It Rong™".
> 
> This latest version totally works on windows as well as mac (and therefore,
I'm
> assuming it works on linux). It is also more readable!

(Now I moved to `type -Pp` instead of which, because then python_git_runner can
be chmod -x)

[mmoss, 2014-03-11 01:16:46]

lgtm

[mmoss, 2014-03-11 03:18:24]

On 2014/03/11 01:16:46, mmoss wrote:
> lgtm

remove p: lgtm again

[iannucci, 2014-03-11 05:07:43]

The CQ bit was checked by iannucci@chromium.org

[commit-bot: I haz the power, 2014-03-11 05:07:50]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/iannucci@chromium.org/188383002/140001

[commit-bot: I haz the power, 2014-03-11 05:10:02]

Change committed as 256131