Avoid ugly failure mode when moving content from a local repository that is not available.

Prelude.undefined error message was introduced by
bb4f31a0ee496ffb83d31cc56f8827e47605d763.

It seems best to filter out local repositories that cannot be accessed
from the list of remotes, rather than keeping them in and making every
thing that uses the list have to deal with remotes that may have an unknown
location.

Besides fixing the error message, this also makes unavailable local
remotes' names not be shown in various messages, including in git annex
status output.

Also, move --to an unavailable local repository now avoids some ugly
errors like "changeWorkingDirectory: does not exist".

5 files changed, 51 insertions, 35 deletions

diff --git a/Git.hs b/Git.hs
index 7d6420563..eab33f19d 100644
--- a/Git.hs
+++ b/Git.hs
@@ -19,6 +19,7 @@ module Git (
 	repoIsHttp,
 	repoIsLocal,
 	repoIsLocalBare,
+	repoIsLocalUnknown,
 	repoDescribe,
 	repoLocation,
 	repoPath,
@@ -99,6 +100,10 @@ repoIsLocalBare :: Repo -> Bool
 repoIsLocalBare Repo { location = Local { worktree = Nothing } } = True
 repoIsLocalBare _ = False
 
+repoIsLocalUnknown :: Repo -> Bool
+repoIsLocalUnknown Repo { location = LocalUnknown { } } = True
+repoIsLocalUnknown _ = False
+
 assertLocal :: Repo -> a -> a
 assertLocal repo action
 	| repoIsUrl repo = error $ unwords
diff --git a/Remote.hs b/Remote.hs
index 839c6ddb0..e211ef7cb 100644
--- a/Remote.hs
+++ b/Remote.hs
@@ -75,7 +75,7 @@ byName' :: String -> Annex (Either String Remote)
 byName' "" = return $ Left "no remote specified"
 byName' n = handle . filter matching <$> remoteList
 	where
-		handle [] = Left $ "there is no git remote named \"" ++ n ++ "\""
+		handle [] = Left $ "there is no available git remote named \"" ++ n ++ "\""
 		handle match = Right $ Prelude.head match
 		matching r = n == name r || toUUID n == uuid r
 
diff --git a/Remote/Git.hs b/Remote/Git.hs
index cf7542d74..df74a769c 100644
--- a/Remote/Git.hs
+++ b/Remote/Git.hs
@@ -42,7 +42,8 @@ remote = RemoteType {
 list :: Annex [Git.Repo]
 list = do
 	c <- fromRepo Git.config
-	mapM (tweakurl c) =<< fromRepo Git.remotes
+	rs <- mapM (tweakurl c) =<< fromRepo Git.remotes
+	catMaybes <$> mapM configread rs
 	where
 		annexurl n = "remote." ++ n ++ ".annexurl"
 		tweakurl c r = do
@@ -52,41 +53,47 @@ list = do
 				Just url -> inRepo $ \g ->
 					Git.Construct.remoteNamed n $
 						Git.Construct.fromRemoteLocation url g
+		{- It's assumed to be cheap to read the config of non-URL
+		 - remotes, so this is done each time git-annex is run
+		 - in a way that uses remotes.
+		 - Conversely, the config of an URL remote is only read
+		 - when there is no cached UUID value. -}
+		configread r = do
+			notignored <- repoNotIgnored r
+			u <- getRepoUUID r
+			r' <- case (repoCheap r, notignored, u) of
+				(_, False, _) -> return r
+				(True, _, _) -> tryGitConfigRead r
+				(False, _, NoUUID) -> tryGitConfigRead r
+				_ -> return r
+			{- A repo with a LocalUnknown location is not currently
+			 - accessible, so skip it. -}
+			if Git.repoIsLocalUnknown r'
+				then return Nothing
+				else return $ Just r'
 
-gen :: Git.Repo -> UUID -> Maybe RemoteConfig -> Annex Remote
-gen r u _ = do
- 	{- It's assumed to be cheap to read the config of non-URL remotes,
-	 - so this is done each time git-annex is run. Conversely,
-	 - the config of an URL remote is only read when there is no
-	 - cached UUID value. -}
-	let cheap = not $ Git.repoIsUrl r
-	notignored <- repoNotIgnored r
-	r' <- case (cheap, notignored, u) of
-		(_, False, _) -> return r
-		(True, _, _) -> tryGitConfigRead r
-		(False, _, NoUUID) -> tryGitConfigRead r
-		_ -> return r
-
-	u' <- getRepoUUID r'
-
-	let defcst = if cheap then cheapRemoteCost else expensiveRemoteCost
-	cst <- remoteCost r' defcst
+repoCheap :: Git.Repo -> Bool
+repoCheap = not . Git.repoIsUrl
 
-	return Remote {
-		uuid = u',
-		cost = cst,
-		name = Git.repoDescribe r',
-		storeKey = copyToRemote r',
-		retrieveKeyFile = copyFromRemote r',
-		retrieveKeyFileCheap = copyFromRemoteCheap r',
-		removeKey = dropKey r',
-		hasKey = inAnnex r',
-		hasKeyCheap = cheap,
-		whereisKey = Nothing,
-		config = Nothing,
-		repo = r',
-		remotetype = remote
-	}
+gen :: Git.Repo -> UUID -> Maybe RemoteConfig -> Annex Remote
+gen r u _ = new <$> remoteCost r defcst
+	where
+		defcst = if repoCheap r then cheapRemoteCost else expensiveRemoteCost
+		new cst = Remote {
+			uuid = u,
+			cost = cst,
+			name = Git.repoDescribe r,
+			storeKey = copyToRemote r,
+			retrieveKeyFile = copyFromRemote r,
+			retrieveKeyFileCheap = copyFromRemoteCheap r,
+			removeKey = dropKey r,
+			hasKey = inAnnex r,
+			hasKeyCheap = repoCheap r,
+			whereisKey = Nothing,
+			config = Nothing,
+			repo = r,
+			remotetype = remote
+		}
 
 {- Tries to read the config for a specified remote, updates state, and
  - returns the updated repo. -}
diff --git a/debian/changelog b/debian/changelog
index 92e992ed7..59eb63b64 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -3,6 +3,8 @@ git-annex (3.20120625) UNRELEASED; urgency=low
   * cabal: Only try to use inotify on Linux.
   * Version build dependency on STM, and allow building without it,
     which disables the watch command.
+  * Avoid ugly failure mode when moving content from a local repository
+    that is not available.
 
  -- Joey Hess <joeyh@debian.org>  Mon, 25 Jun 2012 11:38:12 -0400
 
diff --git a/doc/bugs/undefined.mdwn b/doc/bugs/undefined.mdwn
index 3c157424c..8ee37f034 100644
--- a/doc/bugs/undefined.mdwn
+++ b/doc/bugs/undefined.mdwn
@@ -1,3 +1,5 @@
 Trying to move files from a local remote that is not mounted:
 
 	git-annex: Prelude.undefined
+
+> [[fixed|done]] --[[Joey]]