Use 303 for HTTP/1.1 (#217)

yesod-core/Yesod/Handler.hs

@@ -455,7 +455,13 @@ safeEh er = YesodApp $ \_ _ _ session -> do
 -- a 302. If at some future date it is determined that virtually all clients
 -- understand 303, this implementation will switch to that status code.
 redirect :: RedirectUrl master url => url -> GHandler sub master a
-redirect = redirectWith H.status302
+redirect url = do
+    req <- waiRequest
+    let status =
+            if W.httpVersion req == H.http11
+                then H.status303
+                else H.status302
+    redirectWith status url
 
 -- | Redirect to the given URL with the specified status code.
 redirectWith :: RedirectUrl master url => H.Status -> url -> GHandler sub master a

yesod-core/test/YesodCoreTest/Redirect.hs

@@ -43,10 +43,17 @@ specs = describe "Redirect" [
       assertStatus 307 res
       assertBodyContains "" res
 
-  , it "302 redirect for regular" $ app $ do
+  , it "303 redirect for regular, HTTP 1.1" $ app $ do
       res <- request defaultRequest {
         pathInfo = ["rregular"]
       }
+      assertStatus 303 res
+      assertBodyContains "" res
+  , it "302 redirect for regular, HTTP 1.0" $ app $ do
+      res <- request defaultRequest {
+        pathInfo = ["rregular"]
+      , httpVersion = H.http10
+      }
       assertStatus 302 res
       assertBodyContains "" res
   ]