fix Response.make content-length header

netlib/http/response.py

@@ -84,15 +84,6 @@ class Response(message.Message):
             (),
             None
         )
-        # Assign this manually to update the content-length header.
-        if isinstance(content, bytes):
-            resp.content = content
-        elif isinstance(content, str):
-            resp.text = content
-        else:
-            raise TypeError("Expected content to be str or bytes, but is {}.".format(
-                type(content).__name__
-            ))
 
         # Headers can be list or dict, we differentiate here.
         if isinstance(headers, dict):
@@ -104,6 +95,16 @@ class Response(message.Message):
                 type(headers).__name__
             ))
 
+        # Assign this manually to update the content-length header.
+        if isinstance(content, bytes):
+            resp.content = content
+        elif isinstance(content, str):
+            resp.text = content
+        else:
+            raise TypeError("Expected content to be str or bytes, but is {}.".format(
+                type(content).__name__
+            ))
+
         return resp
 
     @property

test/netlib/http/test_response.py

@@ -34,6 +34,11 @@ class TestResponseCore(object):
         assert r.status_code == 200
         assert r.content == b""
 
+        r = Response.make(418, "teatime")
+        assert r.status_code == 418
+        assert r.content == b"teatime"
+        assert r.headers["content-length"] == "7"
+
         Response.make(content=b"foo")
         Response.make(content="foo")
         with raises(TypeError):