[pitivi] tests_: Make sure not to save and use any config data from actual user space

[Alexandru Băluț <alexbalut src gnome org>]

commit 77cc0d87f2f2e080b54d745f8d44ef655a61870c
Author: Thibault Saunier <thibault saunier osg samsung com>
Date:   Thu Jan 26 01:23:04 2017 +0100

    tests_: Make sure not to save and use any config data from actual user space
    
    Fixes T7677
    
    Reviewed-by: Alex Băluț <alexandru balut gmail com>
    Differential Revision: https://phabricator.freedesktop.org/D1595

 tests/__init__.py |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)
---
diff --git a/tests/__init__.py b/tests/__init__.py
index 31e45f9..7a83955 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -6,6 +6,7 @@ import glob
 import os
 import sys
 import unittest
+from tempfile import mkdtemp
 
 
 def get_pitivi_dir():
@@ -29,7 +30,11 @@ def _prepend_env_paths(**args):
 
 def setup():
     """Sets paths and initializes modules, to be able to run the tests."""
-    res = True
+    # Make sure xdg_*_home return temp dirs, to avoid touching
+    # the config files of the developer.
+    os.environ['XDG_DATA_HOME'] = mkdtemp()
+    os.environ['XDG_CONFIG_HOME'] = mkdtemp()
+    os.environ['XDG_CACHE_HOME'] = mkdtemp()
 
     # Make available to configure.py the top level dir.
     pitivi_dir = get_pitivi_dir()