Windows: Fix locking issue that prevented the webapp starting (since 5.20140707).

Reversion introduced in 9fb8038166.
The locking code was wrong; the webapp re-ran itself, saw pid was locked,
and so didn't start!

Assistant.hs

@@ -102,7 +102,6 @@ startDaemon assistant foreground startdelay cannotrun listenhost startbrowser =
 		createAnnexDirectory (parentDir logfile)
 		ifM (liftIO $ isNothing <$> getEnv flag)
 			( liftIO $ withFile devNull WriteMode $ \nullh -> do
-				Utility.Daemon.lockPidFile pidfile
 				when (not foreground) $
 					debugM desc $ "logging to " ++ logfile
 				loghandle <- openLog logfile
@@ -116,7 +115,7 @@ startDaemon assistant foreground startdelay cannotrun listenhost startbrowser =
 					, std_err = UseHandle loghandle
 					}
 				exitWith =<< waitForProcess pid
-			, start id $ do
+			, start (Utility.Daemon.foreground (Just pidfile)) $
 				case startbrowser of
 					Nothing -> Nothing
 					Just a -> Just $ a Nothing Nothing

Utility/Daemon.hs

@@ -21,6 +21,8 @@ import Utility.WinLock
 #ifndef mingw32_HOST_OS
 import System.Posix
 import Control.Concurrent.Async
+#else
+import System.Exit
 #endif
 
 #ifndef mingw32_HOST_OS
@@ -54,15 +56,26 @@ daemonize logfd pidfile changedirectory a = do
 		wait =<< asyncWithUnmask (\unmask -> unmask a)
 		out
 	out = exitImmediately ExitSuccess
+#endif
 
 {- To run an action that is normally daemonized in the forground. -}
+#ifndef mingw32_HOST_OS
 foreground :: Fd -> Maybe FilePath -> IO () -> IO ()
 foreground logfd pidfile a = do
+#else
+foreground :: Maybe FilePath -> IO () -> IO ()
+foreground pidfile a = do
+#endif
 	maybe noop lockPidFile pidfile
+#ifndef mingw32_HOST_OS
 	_ <- tryIO createSession
 	redirLog logfd
+#endif
 	a
+#ifndef mingw32_HOST_OS
 	exitImmediately ExitSuccess
+#else
+	exitWith ExitSuccess
 #endif
 
 {- Locks the pid file, with an exclusive, non-blocking lock,

debian/changelog

@@ -13,6 +13,8 @@ git-annex (5.20140710) UNRELEASED; urgency=medium
     resolver.
   * Deal with change in git 2.0 that made indirect mode merge conflict
     resolution leave behind old files.
+  * Windows: Fix locking issue that prevented the webapp starting
+    (since 5.20140707).
 
  -- Joey Hess <joeyh@debian.org>  Wed, 09 Jul 2014 23:29:21 -0400