variable referenced before assignment error in keystone.contrib.federation.idp._sign_assertion

[Roman Bogorodskiy]

The _sign_assertion() function from keystone.contrib.federation.idp assigns file_path variable in the try block and then tries to clean up the file in the finally block.

However, if fileutils.write_to_tempfile call raises then file_path is not assigned that results in UnboundLocalError:

      File "keystone/contrib/federation/idp.py", line 437, in _sign_assertion
        os.remove(file_path)
    UnboundLocalError: local variable 'file_path' referenced before assignment

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/208163
Committed: https://git.openstack.org/cgit/openstack/keystone/commit/?id=defa9eeb51dbe8c035df911b18ab58b41459be80
Submitter: Jenkins
Branch: master

commit defa9eeb51dbe8c035df911b18ab58b41459be80
Author: Roman Bogorodskiy <email address hidden>
Date: Sat Aug 1 18:55:29 2015 +0300

    Fix unbound error in federation _sign_assertion

    The _sign_assertion() function from keystone.contrib.federation.idp
    assigns file_path variable in the try block and then tries to clean
    up the file in the finally block.

    However, if fileutils.write_to_tempfile call raises then file_path
    is not assigned that results in UnboundLocalError.

    Fix it by explicitly set file_path to None before calling
    fileutils.write_to_tempfile.

    Closes-Bug: #1481274
    Change-Id: Ib835c0980c20ceb791f1bed314a94e63c9cba910