Prevent key names from containing newlines.

There are several places where it's assumed a key can be written on one
line. One is in the format of the .git/annex/unused files. The difficult
one is that filenames derived from keys are fed into git cat-file --batch,
which has a line based input. (And no -z option.)

So, for now it's best to block such keys being created.

Backend.hs

@@ -64,7 +64,13 @@ genKey' (b:bs) file = do
 	r <- (B.getKey b) file
 	case r of
 		Nothing -> genKey' bs file
-		Just k -> return $ Just (k, b)
+		Just k -> return $ Just (makesane k, b)
+	where
+		-- keyNames should not contain newline characters.
+		makesane k = k { keyName = map fixbadchar (keyName k) }
+		fixbadchar c
+			| c == '\n' = '_'
+			| otherwise = c
 
 {- Looks up the key and backend corresponding to an annexed file,
  - by examining what the file symlinks to. -}

Backend/SHA.hs

@@ -90,10 +90,12 @@ keyValueE size file = keyValue size file >>= maybe (return Nothing) addE
 			, keyBackendName = shaNameE size
 			}
 		naiveextension = takeExtension file
-		extension = 
-			if length naiveextension > 6
-				then "" -- probably not really an extension
-				else naiveextension
+		extension
+			-- long or newline containing extensions are 
+			-- probably not really an extension
+			| length naiveextension > 6 ||
+			  '\n' `elem` naiveextension = ""
+			| otherwise = naiveextension
 
 {- A key's checksum is checked during fsck. -}
 checkKeyChecksum :: SHASize -> Key -> Annex Bool

debian/changelog

@@ -2,6 +2,7 @@ git-annex (3.20111204) UNRELEASED; urgency=low
 
   * map: Fix a failure to detect a loop when both repositories are local
     and refer to each other with relative paths.
+  * Prevent key names from containing newlines.
 
  -- Joey Hess <joeyh@debian.org>  Sun, 04 Dec 2011 12:22:37 -0400
 

doc/bugs/bad_behaviour_with_file_names_with_newline_in_them.mdwn

@@ -1,3 +1,5 @@
 Found this out the hard way.  See the comment in the below post for what happens.
 
 [[/forum/git_annex_add_crash_and_subsequent_recovery/]]
+
+> [[fixed|done]] --[[Joey]]