make segmentXargs preserve order

Assistant/Threads/Committer.hs

@@ -290,7 +290,7 @@ handleAdds havelsof delayadd cs = returnWhen (null incomplete) $ do
 	-- files. The ls-files is run on a batch of files.
 	findnew [] = return ([], noop)
 	findnew pending@(exemplar:_) = do
-		let segments = segmentXargs $ map changeFile pending
+		let segments = segmentXargsUnordered $ map changeFile pending
 		rs <- liftAnnex $ forM segments $ \fs ->
 			inRepo (Git.LsFiles.notInRepo False fs)
 		let (newfiles, cleanup) = foldl'
@@ -457,7 +457,7 @@ safeToAdd havelsof delayadd pending inprocess = do
 	 -}
 	findopenfiles keysources = ifM crippledFileSystem
 		( liftIO $ do
-			let segments = segmentXargs $ map keyFilename keysources
+			let segments = segmentXargsUnordered $ map keyFilename keysources
 			concat <$> forM segments (\fs -> Lsof.query $ "--" : fs)
 		, do
 			tmpdir <- fromRepo gitAnnexTmpMiscDir

Utility/SafeCommand.hs

@@ -101,12 +101,15 @@ prop_idempotent_shellEscape s = [s] == (shellUnEscape . shellEscape) s
 prop_idempotent_shellEscape_multiword :: [String] -> Bool
 prop_idempotent_shellEscape_multiword s = s == (shellUnEscape . unwords . map shellEscape) s
 
-{- Segements a list of filenames into groups that are all below the manximum
- - command-line length limit. Does not preserve order. -}
-segmentXargs :: [FilePath] -> [[FilePath]]
-segmentXargs l = go l [] 0 []
+{- Segments a list of filenames into groups that are all below the maximum
+ - command-line length limit. -}
+segmentXargsOrdered :: [FilePath] -> [[FilePath]]
+segmentXargsOrdered = reverse . map reverse . segmentXargsUnordered
+
+segmentXargsUnordered :: [FilePath] -> [[FilePath]]
+segmentXargsUnordered l = go l [] 0 []
   where
-	go [] c _ r = c:r
+	go [] c _ r = (c:r)
 	go (f:fs) c accumlen r
 		| len < maxlen && newlen > maxlen = go (f:fs) [] 0 (c:r)
 		| otherwise = go fs (f:c) newlen r