support building with yesod-default 1.1.0

Old 1.0.1 version is still supported as well. Cabal autodetects
which version is available, but in the Makefile, WITH_OLD_YESOD
has to be configured appropriately.

I have not squashed all the $newline warnings with the new Yesod.
They should go away eventually anyway as Yesod moves past that transition.

Makefile

@@ -2,7 +2,7 @@ CFLAGS=-Wall
 GIT_ANNEX_TMP_BUILD_DIR?=tmp
 IGNORE=-ignore-package monads-fd -ignore-package monads-tf
 BASEFLAGS=-threaded -Wall $(IGNORE) -outputdir $(GIT_ANNEX_TMP_BUILD_DIR) -IUtility
-FEATURES=-DWITH_ASSISTANT -DWITH_S3 -DWITH_WEBAPP
+FEATURES=-DWITH_ASSISTANT -DWITH_S3 -DWITH_WEBAPP -DWITH_OLD_YESOD
 
 bins=git-annex
 mans=git-annex.1 git-annex-shell.1

Utility/WebApp.hs

@@ -26,6 +26,7 @@ import Crypto.Random
 import Data.Digest.Pure.SHA
 import qualified Web.ClientSession as CS
 import qualified Data.ByteString.Lazy as L
+import qualified Data.ByteString as B
 import qualified Data.Text as T
 import qualified Data.Text.Encoding as TE
 import Blaze.ByteString.Builder.Char.Utf8 (fromText)
@@ -113,7 +114,7 @@ logRequest req = do
 	where
 		frombs v = toString $ L.fromChunks [v]
 
-lookupRequestField :: CI.CI Ascii -> Wai.Request -> Ascii
+lookupRequestField :: CI.CI B.ByteString -> Wai.Request -> B.ByteString
 lookupRequestField k req = fromMaybe "" . lookup k $ Wai.requestHeaders req
 
 {- Rather than storing a session key on disk, use a random key

Utility/Yesod.hs

@@ -5,13 +5,27 @@
  - Licensed under the GNU GPL version 3 or higher.
  -}
 
+{-# LANGUAGE CPP #-}
+
 module Utility.Yesod where
 
 import Yesod.Default.Util
 import Language.Haskell.TH.Syntax
+#ifndef WITH_OLD_YESOD
+import Data.Default (def)
+import Text.Hamlet
+#endif
 
 widgetFile :: String -> Q Exp
+#ifdef WITH_OLD_YESOD
 widgetFile = widgetFileNoReload
+#else
+widgetFile = widgetFileNoReload $ def
+	{ wfsHamletSettings = defaultHamletSettings
+		{ hamletNewlines = AlwaysNewlines
+		}
+	}
+#endif
 
 hamletTemplate :: FilePath -> FilePath
 hamletTemplate f = globFile "hamlet" f

git-annex.cabal

@@ -40,6 +40,12 @@ Flag Assistant
 Flag Webapp
   Description: Enable git-annex webapp
 
+Flag CurrentYesod
+  Description: Using a current version of Yesod
+
+Flag OldYesod
+  Description: Using an old version of Yesod
+
 Executable git-annex
   Main-Is: git-annex.hs
   Build-Depends: MissingH, hslogger, directory, filepath,
@@ -73,8 +79,15 @@ Executable git-annex
     Build-Depends: dbus
     CPP-Options: -DWITH_DBUS
 
-  if flag(Webapp)
-    Build-Depends: yesod, yesod-static, yesod-default, case-insensitive,
+  if flag(CurrentYesod)
+    Build-Depends: yesod-default (>= 1.1.0)
+
+  if flag(OldYesod)
+    Build-Depends: yesod-default (<= 1.0.1.1)
+    CPP-Options: -DWITH_OLD_YESOD
+
+  if flag(Webapp) && (flag(CurrentYesod) || flag(OldYesod))
+    Build-Depends: yesod, yesod-static, case-insensitive,
      http-types, transformers, wai, wai-logger, warp, blaze-builder,
      blaze-html, crypto-api, hamlet, clientsession,
      template-haskell