We explicitly pass in the interfaces provided by the request as

request_iface to _call_view; we don't want _call_view to use
request.request_iface, because render_view_to_response and friends are
pretty much limited to finding views that are not views associated with
routes, and the only thing request.request_iface is used for is to find
route-based views.  The render_view_to_response API is (and always has
been) a stepchild API reserved for use of those who actually use
traversal.  Doing this fixes an infinite recursion bug introduced in
Pyramid 1.6a1, and causes the render_view* APIs to behave as they did in
1.5 and previous. We should probably provide some sort of different API
that would allow people to find views for routes.

Fixes #1643.

pyramid/tests/test_view.py

@@ -185,6 +185,20 @@ def anotherview(context, request):
         self.assertEqual(response.status, '200 OK')
         self.assertEqual(response.app_iter, ['anotherview'])
 
+    def test_call_view_with_request_iface_on_request(self):
+        # See https://github.com/Pylons/pyramid/issues/1643
+        from zope.interface import Interface
+        class IWontBeFound(Interface): pass
+        context = self._makeContext()
+        request = self._makeRequest()
+        request.request_iface = IWontBeFound
+        response = DummyResponse('aview')
+        view = make_view(response)
+        self._registerView(request.registry, view, 'aview')
+        response = self._callFUT(context, request, name='aview')
+        self.assertEqual(response.status, '200 OK')
+        self.assertEqual(response.app_iter, ['aview'])
+
 class RenderViewToIterableTests(BaseTest, unittest.TestCase):
     def _callFUT(self, *arg, **kw):
         from pyramid.view import render_view_to_iterable

pyramid/view.py

@@ -49,6 +49,19 @@ def render_view_to_response(context, request, name='', secure=True):
         registry = get_current_registry()
 
     context_iface = providedBy(context)
+    # We explicitly pass in the interfaces provided by the request as
+    # request_iface to _call_view; we don't want _call_view to use
+    # request.request_iface, because render_view_to_response and friends are
+    # pretty much limited to finding views that are not views associated with
+    # routes, and the only thing request.request_iface is used for is to find
+    # route-based views.  The render_view_to_response API is (and always has
+    # been) a stepchild API reserved for use of those who actually use
+    # traversal.  Doing this fixes an infinite recursion bug introduced in
+    # Pyramid 1.6a1, and causes the render_view* APIs to behave as they did in
+    # 1.5 and previous. We should probably provide some sort of different API
+    # that would allow people to find views for routes.  See
+    # https://github.com/Pylons/pyramid/issues/1643 for more info.
+    request_iface = providedBy(request)
 
     response = _call_view(
         registry,
@@ -57,6 +70,7 @@ def render_view_to_response(context, request, name='', secure=True):
         context_iface,
         name,
         secure=secure,
+        request_iface=request_iface,
         )
 
     return response # NB: might be None