Pre-downloaded pip installation file not extracted on fresh install

[Renjie Sun]

Pre-downloaded pip installation file files/pip-*.tar.gz is not extracted on fresh install, resulting in error:
2014-05-24 21:36:03.552 | /home/r/devstack/tools/install_pip.sh: line 79: cd: /home/r/devstack/files/pip-1.4.1: No such file or directory

How to reproduce the error:
1. Install a clean ubuntu/fedora OS.
2. Clone the latest devstack repo from github.
3. Download pip installation file (now pip-1.4.1.tar.gz) and put it at directory 'files'.
4. Start the installation.

A patch is proposed as:

diff --git a/tools/install_pip.sh b/tools/install_pip.sh
index 5f01eb6..b55fa4f 100755
--- a/tools/install_pip.sh
+++ b/tools/install_pip.sh
@@ -73,9 +73,10 @@ function install_get_pip {
 function install_pip_tarball {
     if [[ ! -r $FILES/pip-$INSTALL_PIP_VERSION.tar.gz ]]; then
         (cd $FILES; \
- curl -O $PIP_TAR_URL; \
- tar xvfz pip-$INSTALL_PIP_VERSION.tar.gz 1>/dev/null)
+ curl -O $PIP_TAR_URL)
     fi
+ rm -rf $FILES/pip-$INSTALL_PIP_VERSION
+ tar xfz $FILES/pip-$INSTALL_PIP_VERSION.tar.gz -C $FILES
     (cd $FILES/pip-$INSTALL_PIP_VERSION; \
         sudo -E python setup.py install 1>/dev/null)
 }

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/95400

[OpenStack Infra (hudson-openstack)]

Change abandoned by Sean Dague (<email address hidden>) on branch: master
Review: https://review.openstack.org/95400