Fix git depot_tools update flow.

update_depot_tools.bat

+@echo off
+:: 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.
+
+:: This batch file will try to sync the root directory.
+
+setlocal
+
+:: Will download svn and python.
+:: If you don't want to install the depot_tools version of these tools, remove
+:: the 'force' option on the next command. The tools will be installed only if
+:: not already in the PATH environment variable.
+call "%~dp0bootstrap\win\win_tools.bat" force
+if errorlevel 1 goto :EOF
+
+:: Shall skip automatic update?
+IF "%DEPOT_TOOLS_UPDATE%" == "0" GOTO :EOF
+
+:: We need either .\.svn\. or .\.git\. to be able to sync.
+IF EXIST "%~dp0.svn\." GOTO :SVN_UPDATE
+IF EXIST "%~dp0.git\." GOTO :GIT_UPDATE
+echo Error updating depot_tools, no revision tool found.
+goto :EOF
+
+
+:SVN_UPDATE
+call svn up -q "%~dp0"
+goto :EOF
+
+
+:GIT_UPDATE
+cd "%~dp0"

[M-A Ruel, 2012/03/21 15:05:46]

You should pop back to the current directory afterward, since this side effect
lasts after this script exits. Also, it's not guaranteed that you are on the
right drive letter. I'm not familiar with pushd/popd so you'll have to test a
bit.
You may also need to change line 8 to
setlocal enableextensions


pushd
cd /d "%~dp0"
call git svn rebase -q -q
popd

[gab, 2012/03/21 16:34:50]

Actually I did test this and it looks like, because this is in its own script
and "probably because" setlocal is on, this work, i.e. I call `gclient sync`
from my chromium/src directory and gclient.py correctly syncs that directory
after depot_tools update is done.

You are right about cd /d though as cd will fail otherwise if depot_tools is not
on the same drive as the source... Crazy DOS...

I added /d and just tested with a depot_tools on a separate drive and it works
(i.e. calling gclient sync from G:\google\chromium\src when PATH points to
C:\tmp\depot_tools).

enableextensions in the cd case would only cause it to adjust to bad character
case in the directory spelling (which I hope is correct given it comes from a
DOS variable...): http://www.computerhope.com/cdhlp.htm

+call git svn rebase -q -q
+goto :EOF