two types of byName

Clean up from 9769235d6b.
In some cases, looking up a remote by name even though it has no UUID is
desirable. This includes git annex sync, which can operate on remotes
without an annex, and XMPP pairing, which runs addRemote (with calls
byName) before the UUID of the XMPP remote has been configured in git.

Assistant/MakeRemote.hs

@@ -52,7 +52,8 @@ addRemote :: Annex String -> Annex Remote
 addRemote a = do
 	name <- a
 	void remoteListRefresh
-	maybe (error "failed to add remote") return =<< Remote.byName (Just name)
+	maybe (error "failed to add remote") return
+		=<< Remote.byName (Just name)
 
 {- Inits a rsync special remote, and returns its name. -}
 makeRsyncRemote :: String -> String -> Annex String

Command/Copy.hs

@@ -18,8 +18,8 @@ def = [withOptions Command.Move.options $ command "copy" paramPaths seek
 	"copy content of files to/from another repository"]
 
 seek :: [CommandSeek]
-seek = [withField Command.Move.toOption Remote.byName $ \to ->
+seek = [withField Command.Move.toOption Remote.byNameWithUUID $ \to ->
-		withField Command.Move.fromOption Remote.byName $ \from ->
+		withField Command.Move.fromOption Remote.byNameWithUUID $ \from ->
 			withFilesInGit $ whenAnnexed $ start to from]
 
 {- A copy is just a move that does not delete the source file.

Command/Drop.hs

@@ -27,7 +27,7 @@ fromOption :: Option
 fromOption = Option.field ['f'] "from" paramRemote "drop content from a remote"
 
 seek :: [CommandSeek]
-seek = [withField fromOption Remote.byName $ \from ->
+seek = [withField fromOption Remote.byNameWithUUID $ \from ->
 	withFilesInGit $ whenAnnexed $ start from]
 
 start :: Maybe Remote -> FilePath -> (Key, Backend) -> CommandStart

Command/DropUnused.hs

@@ -28,7 +28,7 @@ start :: UnusedMaps -> Int -> CommandStart
 start = startUnused "dropunused" perform (performOther gitAnnexBadLocation) (performOther gitAnnexTmpLocation)
 
 perform :: Key -> CommandPerform
-perform key = maybe droplocal dropremote =<< Remote.byName =<< from
+perform key = maybe droplocal dropremote =<< Remote.byNameWithUUID =<< from
   where
 	dropremote r = do
 		showAction $ "from " ++ Remote.name r

Command/Fsck.hs

@@ -61,7 +61,7 @@ options =
 
 seek :: [CommandSeek]
 seek =
-	[ withField fromOption Remote.byName $ \from ->
+	[ withField fromOption Remote.byNameWithUUID $ \from ->
 	  withIncremental $ \i -> withFilesInGit $ whenAnnexed $ start from i
 	, withIncremental $ \i -> withBarePresentKeys $ startBare i
 	]

Command/Get.hs

@@ -20,7 +20,7 @@ def = [withOptions [Command.Move.fromOption] $ command "get" paramPaths seek
 	"make content of annexed files available"]
 
 seek :: [CommandSeek]
-seek = [withField Command.Move.fromOption Remote.byName $ \from ->
+seek = [withField Command.Move.fromOption Remote.byNameWithUUID $ \from ->
 	withFilesInGit $ whenAnnexed $ start from]
 
 start :: Maybe Remote -> FilePath -> (Key, Backend) -> CommandStart

Command/Move.hs

@@ -32,8 +32,8 @@ options :: [Option]
 options = [fromOption, toOption]
 
 seek :: [CommandSeek]
-seek = [withField toOption Remote.byName $ \to ->
+seek = [withField toOption Remote.byNameWithUUID $ \to ->
-		withField fromOption Remote.byName $ \from ->
+		withField fromOption Remote.byNameWithUUID $ \from ->
 			withFilesInGit $ whenAnnexed $ start to from True]
 
 start :: Maybe Remote -> Maybe Remote -> Bool -> FilePath -> (Key, Backend) -> CommandStart

Command/TransferKey.hs

@@ -29,8 +29,8 @@ fileOption :: Option
 fileOption = Option.field [] "file" paramFile "the associated file"
 
 seek :: [CommandSeek]
-seek = [withField Command.Move.toOption Remote.byName $ \to ->
+seek = [withField Command.Move.toOption Remote.byNameWithUUID $ \to ->
-	withField Command.Move.fromOption Remote.byName $ \from ->
+	withField Command.Move.fromOption Remote.byNameWithUUID $ \from ->
 	withField fileOption return $ \file ->
 		withKeys $ start to from file]
 

Command/Unused.hs

@@ -76,7 +76,7 @@ checkUnused = chain 0
 		chain v' as
 
 checkRemoteUnused :: String -> CommandPerform
-checkRemoteUnused name = go =<< fromJust <$> Remote.byName (Just name)
+checkRemoteUnused name = go =<< fromJust <$> Remote.byNameWithUUID (Just name)
   where
 	go r = do
 		showAction "checking for unused data"

Remote.hs

@@ -24,6 +24,7 @@ module Remote (
 	remoteMap,
 	uuidDescriptions,
 	byName,
+	byNameWithUUID,
 	byCost,
 	prettyPrintUUIDs,
 	prettyListUUIDs,
@@ -72,18 +73,27 @@ addName desc n
 	| otherwise = n ++ " (" ++ desc ++ ")"
 
 {- When a name is specified, looks up the remote matching that name.
- - (Or it can be a UUID.) Only finds currently configured git remotes. -}
+ - (Or it can be a UUID.) -}
 byName :: Maybe String -> Annex (Maybe Remote)
 byName Nothing = return Nothing
 byName (Just n) = either error Just <$> byName' n
+
+{- Like byName, but the remote must have a configured UUID. -}
+byNameWithUUID :: Maybe String -> Annex (Maybe Remote)
+byNameWithUUID n = do
+	v <- byName n
+	return $ checkuuid <$> v
+  where
+	checkuuid r
+		| uuid r == NoUUID = error $ "cannot determine uuid for " ++ name r
+		| otherwise = r
+
 byName' :: String -> Annex (Either String Remote)
 byName' "" = return $ Left "no remote specified"
 byName' n = handle . filter matching <$> remoteList
   where
 	handle [] = Left $ "there is no available git remote named \"" ++ n ++ "\""
-	handle (match:_)
+	handle (match:_) = Right match
-		| uuid match == NoUUID = Left $ "cannot determine uuid for " ++ name match
-		| otherwise = Right match
 	matching r = n == name r || toUUID n == uuid r
 
 {- Looks up a remote by name (or by UUID, or even by description),