Moved open_session call from RequestContext.push to wsgi_app

flask/app.py

@@ -1924,6 +1924,15 @@ def test_request_context(self, *args, **kwargs):
         finally:
             builder.close()
 
+    def ctx_open_session(self):
+        """Opens session for current request context using session_interface.
+        """
+        ctx = _request_ctx_stack.top
+        session = self.open_session(ctx.request)
+        if session is None:
+            session = self.make_null_session()
+        ctx.session = session
+
     def wsgi_app(self, environ, start_response):
         """The actual WSGI application.  This is not implemented in
         `__call__` so that middlewares can be applied without losing a
@@ -1954,6 +1963,7 @@ def wsgi_app(self, environ, start_response):
         error = None
         try:
             try:
+                self.ctx_open_session()
                 response = self.full_dispatch_request()
             except Exception as e:
                 error = e

flask/ctx.py

@@ -325,14 +325,6 @@ def push(self):
 
         _request_ctx_stack.push(self)
 
-        # Open the session at the moment that the request context is
-        # available. This allows a custom open_session method to use the
-        # request context (e.g. code that access database information
-        # stored on `g` instead of the appcontext).
-        self.session = self.app.open_session(self.request)
-        if self.session is None:
-            self.session = self.app.make_null_session()
-
     def pop(self, exc=_sentinel):
         """Pops the request context and unbinds it by doing that.  This will
         also trigger the execution of functions registered by the

tests/test_appctx.py

@@ -43,6 +43,34 @@ def test_request_context_means_app_context():
         assert flask.current_app._get_current_object() == app
     assert flask._app_ctx_stack.top is None
 
+def test_request_context_reset_correctly():
+    app = flask.Flask(__name__)
+
+    class BadSessionInterface(object):
+
+        """Fails once."""
+        fail = True
+
+        def open_session(self, *args, **kwargs):
+            if self.fail:
+                setattr(flask.g, "test_g_attr", 1)
+                self.fail = False
+                raise Exception()
+        def make_null_session(self, *args, **kwargs):
+            return None
+
+    app.session_interface = BadSessionInterface()
+
+    try:
+        with app.test_request_context():
+            app.ctx_open_session()
+    except:
+        pass
+
+    with app.test_request_context():
+        app.ctx_open_session()
+        assert getattr(flask.g, "test_g_attr", None) is None
+
 def test_app_context_provides_current_app():
     app = flask.Flask(__name__)
     with app.app_context():

tests/test_basic.py

@@ -314,6 +314,7 @@ def expect_exception(f, *args, **kwargs):
         else:
             assert False, 'expected exception'
     with app.test_request_context():
+        app.ctx_open_session()
         assert flask.session.get('missing_key') is None
         expect_exception(flask.session.__setitem__, 'foo', 42)
         expect_exception(flask.session.pop, 'foo')
@@ -454,6 +455,7 @@ def test_flashes():
     app.secret_key = 'testkey'
 
     with app.test_request_context():
+        app.ctx_open_session()
         assert not flask.session.modified
         flask.flash('Zap')
         flask.session.modified = False