webapp: Now always logs to .git/annex/daemon.log

It used to not log to daemon.log when a repository was first created, and
when starting the webapp. Now both do. Redirecting stdout and stderr to the
log is tricky when starting the webapp, because the web browser may want to
communicate with the user. (Either a console web browser, or web.browser = echo)
This is handled by restoring the original fds when running the browser.

Utility/Daemon.hs

@@ -34,16 +34,22 @@ daemonize logfd pidfile changedirectory a = do
 		when changedirectory $
 			setCurrentDirectory "/"
 		nullfd <- openFd "/dev/null" ReadOnly Nothing defaultFileFlags
-		_ <- redir nullfd stdInput
-		mapM_ (redir logfd) [stdOutput, stdError]
-		closeFd logfd
+		redir nullfd stdInput
+		redirLog logfd
 		a
 		out
-	redir newh h = do
-		closeFd h
-		dupTo newh h
 	out = exitImmediately ExitSuccess
 
+redirLog :: Fd -> IO ()
+redirLog logfd = do
+	mapM_ (redir logfd) [stdOutput, stdError]
+	closeFd logfd
+
+redir :: Fd -> Fd -> IO ()
+redir newh h = do
+	closeFd h
+	void $ dupTo newh h
+
 {- Locks the pid file, with an exclusive, non-blocking lock.
  - Writes the pid to the file, fully atomically.
  - Fails if the pid file is already locked by another process. -}