[py] fix bug introduced in 9a6df49

Author: lmtierney

py/selenium/webdriver/firefox/firefox_profile.py

@@ -80,9 +80,9 @@ def __init__(self, profile_directory=None):
             os.chmod(self.profile_dir, 0o755)
             self._read_existing_userjs(os.path.join(self.profile_dir, "user.js"))
         self.extensionsDir = os.path.join(self.profile_dir, "extensions")
-        os.chmod(self.extensionsDir, 0o755)
         self.userPrefs = os.path.join(self.profile_dir, "user.js")
-        os.chmod(self.userPrefs, 0o644)
+        if os.path.isfile(self.userPrefs):
+            os.chmod(self.userPrefs, 0o644)
 
     # Public Methods
     def set_preference(self, key, value):
@@ -276,11 +276,11 @@ def _install_extension(self, addon, unpack=True):
         assert addon_id, 'The addon id could not be found: %s' % addon
 
         # copy the addon to the profile
-        extensions_path = os.path.join(self.profile_dir, 'extensions')
-        addon_path = os.path.join(extensions_path, addon_id)
+        addon_path = os.path.join(self.extensionsDir, addon_id)
         if not unpack and not addon_details['unpack'] and xpifile:
-            if not os.path.exists(extensions_path):
-                os.makedirs(extensions_path)
+            if not os.path.exists(self.extensionsDir):
+                os.makedirs(self.extensionsDir)
+                os.chmod(self.extensionsDir, 0o755)
             shutil.copy(xpifile, addon_path + '.xpi')
         else:
             if not os.path.exists(addon_path):