addurl: Always use whole url as destination filename, rather than only its file component.

First, this ensures that git annex addurl, when run repeatedly with the
same url, doesn't create duplicate files, which it did before when it
fell back to the longer filename.

Secondly, the file part of an url is frequently not very descriptive on its
own.

The uri scheme, auth, and port is intentionally left out, as clutter.

Command/AddUrl.hs

@@ -7,9 +7,10 @@
 
 module Command.AddUrl where
 
-import Control.Monad.State (liftIO, when)
+import Control.Monad.State
 import Network.URI
 import Data.String.Utils
+import Data.Maybe
 import System.Directory
 
 import Command
@@ -24,6 +25,7 @@ import Content
 import PresenceLog
 import Locations
 import Utility.Path
+import Utility.Conditional
 
 command :: [Command]
 command = [repoCommand "addurl" paramPath seek "add urls to annex"]
@@ -75,20 +77,10 @@ nodownload url file = do
 
 url2file :: URI -> IO FilePath
 url2file url = do
-	let parts = filter safe $ split "/" $ uriPath url
-	if null parts
-		then fallback
-		else do
-			let file = last parts
-			e <- doesFileExist file
-			if e then fallback else return file
+	whenM (doesFileExist file) $
+		error $ "already have this url in " ++ file
+	return file
 	where
-		fallback = do
-			let file = replace "/" "_" $ show url
-			e <- doesFileExist file
-			when e $ error "already have this url"
-			return file
-		safe "" = False
-		safe "." = False
-		safe ".." = False
-		safe _ = True
+		file = escape $ uriRegName auth ++ uriPath url ++ uriQuery url
+		escape = replace "/?" $ repeat '_'
+		auth = fromMaybe (error $ "bad url " ++ show url) $ uriAuthority url