avoid memory leak potential when assigning sys.exc_info() result to an attr of the request

2 files changed, 16 insertions, 6 deletions

diff --git a/pyramid/router.py b/pyramid/router.py
index aa9e4a1ba..ddec23cdb 100644
--- a/pyramid/router.py
+++ b/pyramid/router.py
@@ -168,7 +168,6 @@ class Router(object):
 
         # handle exceptions raised during root finding and view-exec
         except Exception, why:
-            exc_info = sys.exc_info()
             # clear old generated request.response, if any; it may
             # have been mutated by the view, and its state is not
             # sane (e.g. caching headers)
@@ -176,7 +175,7 @@ class Router(object):
                 del attrs['response']
 
             attrs['exception'] = why
-            attrs['exc_info'] = exc_info
+            attrs['exc_info'] = sys.exc_info()
 
             for_ = (IExceptionViewClassifier,
                     request_iface.combined,
@@ -217,8 +216,10 @@ class Router(object):
                 request.registry = registry
                 response = self.handle_request(request)
             finally:
-                if request is not None and request.finished_callbacks:
-                    request._process_finished_callbacks()
+                if request is not None:
+                    if request.finished_callbacks:
+                        request._process_finished_callbacks()
+                    request.exc_info = None # avoid leak
 
             return response(request.environ, start_response)
         finally:
diff --git a/pyramid/tests/test_router.py b/pyramid/tests/test_router.py
index e44465992..b943f1ee6 100644
--- a/pyramid/tests/test_router.py
+++ b/pyramid/tests/test_router.py
@@ -790,6 +790,7 @@ class TestRouter(unittest.TestCase):
         from pyramid.interfaces import IRequest
         from pyramid.interfaces import IViewClassifier
         from pyramid.interfaces import IRequestFactory
+        from pyramid.interfaces import IExceptionViewClassifier
         def rfactory(environ):
             return request
         self.registry.registerUtility(rfactory, IRequestFactory)
@@ -799,16 +800,24 @@ class TestRouter(unittest.TestCase):
         directlyProvides(context, IContext)
         self._registerTraverserFactory(context, subpath=[''])
         response = DummyResponse()
+        response.app_iter = ['OK']
         view = DummyView(response, raise_exception=RuntimeError)
         environ = self._makeEnviron()
+        def exception_view(context, request):
+            self.assertEqual(request.exc_info[0], RuntimeError)
+            return response
         self._registerView(view, '', IViewClassifier, IRequest, IContext)
+        self._registerView(exception_view, '', IExceptionViewClassifier,
+                           IRequest, RuntimeError)
         router = self._makeOne()
         start_response = DummyStartResponse()
-        self.assertRaises(RuntimeError, router, environ, start_response)
+        result = router(environ, start_response)
+        self.assertEqual(result, ['OK'])
         # ``exception`` must be attached to request even if a suitable
         # exception view cannot be found
         self.assertEqual(request.exception.__class__, RuntimeError)
-        self.assertEqual(request.exc_info[0], RuntimeError)
+        # we clean up the exc_info after the request
+        self.assertEqual(request.exc_info, None)
         
     def test_call_view_raises_exception_view(self):
         from pyramid.interfaces import IViewClassifier