reset path_info and script_name after request processing is over

CHANGES.txt

@@ -1,3 +1,10 @@
+unreleased
+----------
+
+- Fix another regression where the toolbar was modifying requests to the
+  toolbar itself such that the ``script_name`` and ``path_info`` were
+  different after handling the request than before.
+
 3.0.2 (2016-07-02)
 ------------------
 

pyramid_debugtoolbar/toolbar.py

@@ -190,9 +190,15 @@ def toolbar_tween(request):
         if p.startswith(root_path):
             # we know root_path will always have a trailing slash
             # but script_name doesn't want it
-            request.script_name += root_path[:-1]
-            request.path_info = request.path_info[len(root_path) - 1:]
-            return dispatch(request)
+            try:
+                old_script_name = request.script_name
+                old_path_info = request.path_info
+                request.script_name += root_path[:-1]
+                request.path_info = request.path_info[len(root_path) - 1:]
+                return dispatch(request)
+            finally:
+                request.script_name = old_script_name
+                request.path_info = old_path_info
 
         request.exc_history = exc_history
         request.history = request_history