resolve conflicts, reword change entry a bit

3 files changed, 33 insertions, 1 deletions

diff --git a/CHANGES.txt b/CHANGES.txt
index 80578d539..7d06999d6 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -8,6 +8,14 @@ Backwards Incompatibilities
   have been deprecated since Pyramid 1.1, and as per the deprecation policy,
   have now been removed.
 
+- ``request.response`` will no longer be mutated when using the 
+  ``pyramid.renderers.render()`` API.  Almost all renderers mutate the 
+   ``request.response`` response object (for 
+   example, the JSON renderer sets ``request.response.content_type`` to
+  ``application/json``), but this is only necessary when the renderer
+  is called by the view execution machinery; it was a bug when it was
+  done as a side effect of calling ``pyramid.renderers.render()``.
+
 1.5a1 (2013-08-30)
 ==================
 
diff --git a/pyramid/renderers.py b/pyramid/renderers.py
index a647d273c..d78335864 100644
--- a/pyramid/renderers.py
+++ b/pyramid/renderers.py
@@ -85,7 +85,23 @@ def render(renderer_name, value, request=None, package=None):
         package = caller_package()
     helper = RendererHelper(name=renderer_name, package=package,
                             registry=registry)
-    return helper.render(value, None, request=request)
+
+    saved_response = None
+    # save the current response, preventing the renderer from affecting it
+    attrs = request.__dict__ if request is not None else {}
+    if 'response' in attrs:
+        saved_response = attrs['response']
+        del attrs['response']
+
+    result = helper.render(value, None, request=request)
+
+    # restore the original response, overwriting any changes
+    if saved_response is not None:
+        attrs['response'] = saved_response
+    elif 'response' in attrs:
+        del attrs['response']
+
+    return result
 
 def render_to_response(renderer_name, value, request=None, package=None):
     """ Using the renderer ``renderer_name`` (a template
diff --git a/pyramid/tests/test_renderers.py b/pyramid/tests/test_renderers.py
index 078373f2e..13a1745a9 100644
--- a/pyramid/tests/test_renderers.py
+++ b/pyramid/tests/test_renderers.py
@@ -840,6 +840,14 @@ class Test_render(unittest.TestCase):
         renderer.assert_(a=1)
         renderer.assert_(request=request)
 
+    def test_it_preserves_response(self):
+        request = testing.DummyRequest()
+        response = object() # should error if mutated
+        request.response = response
+        result = self._callFUT('json', dict(a=1), request=request)
+        self.assertEqual(result, '{"a": 1}')
+        self.assertEqual(request.response, response)
+
 class Test_render_to_response(unittest.TestCase):
     def setUp(self):
         self.config = testing.setUp()