Revert "multiple -m"

This reverts commit cee12f6a2f.

This commit broke git-annex init run in a repo that was cloned from a
repo with an adjusted branch checked out.

The problem is that findAdjustingCommit was not able to identify the
commit that created the adjusted branch. It seems that there is an extra
"\n" at the end of the commit message that it does not expect.

Since backwards compatability needs to be maintained, cannot just make
findAdjustingCommit accept it with the "\n". Will have to instead
have one commitTree variant that uses the old method, and use it for
adjusted branch committing.

Command/Sync.hs

@@ -1,7 +1,7 @@
 {- git-annex command
  -
  - Copyright 2011 Joachim Breitner <mail@joachim-breitner.de>
- - Copyright 2011-2024 Joey Hess <id@joeyh.name>
+ - Copyright 2011-2023 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
@@ -105,7 +105,7 @@ data SyncOptions = SyncOptions
 	, notOnlyAnnexOption :: Bool
 	, commitOption :: Bool
 	, noCommitOption :: Bool
-	, messageOption :: [String]
+	, messageOption :: Maybe String
 	, pullOption :: Bool
 	, pushOption :: Bool
 	, contentOption :: Maybe Bool
@@ -125,7 +125,7 @@ instance Default SyncOptions where
 		, notOnlyAnnexOption = False
 		, commitOption = False
 		, noCommitOption = False
-		, messageOption = []
+		, messageOption = Nothing
 		, pullOption = False
 		, pushOption = False
 		, contentOption = Just False
@@ -169,8 +169,8 @@ optParser mode desc = SyncOptions
 			( long "no-commit"
 			<> help "avoid git commit" 
 			))
-	<*> unlessmode [SyncMode, AssistMode] []
-		(many (strOption
+	<*> unlessmode [SyncMode, AssistMode] Nothing
+		(optional (strOption
 			( long "message" <> short 'm' <> metavar "MSG"
 			<> help "commit message"
 			)))
@@ -402,18 +402,17 @@ syncRemotes' ps available =
 
 commit :: SyncOptions -> CommandStart
 commit o = stopUnless shouldcommit $ starting "commit" ai si $ do
+	commitmessage <- maybe commitMsg return (messageOption o)
 	Annex.Branch.commit =<< Annex.Branch.commitMessage
-	mopts <- concatMap (\msg -> [Param "-m", Param msg])
-		<$> if null (messageOption o)
-			then (:[]) <$> commitMsg
-			else pure (messageOption o)
 	next $ do
 		showOutput
 		let cmode = Git.Branch.ManualCommit
 		cquiet <- Git.Branch.CommitQuiet <$> commandProgressDisabled
-		void $ inRepo $ Git.Branch.commitCommand
-			cmode cquiet
-			([ Param "-a" ] ++ mopts)
+		void $ inRepo $ Git.Branch.commitCommand cmode cquiet
+			[ Param "-a"
+			, Param "-m"
+			, Param commitmessage
+			]
 		return True
   where
 	shouldcommit = notOnlyAnnex o <&&>
@@ -427,8 +426,7 @@ commitMsg :: Annex String
 commitMsg = do
 	u <- getUUID
 	m <- uuidDescMap
-	return $ "git-annex in "
-		++ maybe "unknown" fromUUIDDesc (M.lookup u m)
+	return $ "git-annex in " ++ maybe "unknown" fromUUIDDesc (M.lookup u m)
 
 mergeLocal :: [Git.Merge.MergeConfig] -> SyncOptions -> CurrBranch -> CommandStart
 mergeLocal mergeconfig o currbranch = stopUnless (notOnlyAnnex o) $
@@ -580,7 +578,7 @@ importRemote importcontent o remote currbranch
 			let (branch, subdir) = splitRemoteAnnexTrackingBranchSubdir b
 			if canImportKeys remote importcontent
 				then do
-					Command.Import.seekRemote remote branch subdir importcontent (CheckGitIgnore True) []
+					Command.Import.seekRemote remote branch subdir importcontent (CheckGitIgnore True) Nothing
 					-- Importing generates a branch
 					-- that is not initially connected
 					-- to the current branch, so allow