add createMessage

init: When annex.commitmessage is set, use that message for the commit
that creates the git-annex branch.

This will be used by filter-branch too, and it seems to make sense to let
annex.commitmessage affect it.

Annex/Branch.hs

@@ -24,6 +24,7 @@ module Annex.Branch (
 	change,
 	maybeChange,
 	commitMessage,
+	createMessage,
 	commit,
 	forceCommit,
 	getBranch,
@@ -129,7 +130,8 @@ getBranch = maybe (hasOrigin >>= go >>= use) return =<< branchsha
 			<$> branchsha
 	go False = withIndex' True $ do
 		cmode <- annexCommitMode <$> Annex.getGitConfig
-		inRepo $ Git.Branch.commitAlways cmode "branch created" fullname []
+		cmessage <- createMessage
+		inRepo $ Git.Branch.commitAlways cmode cmessage fullname []
 	use sha = do
 		setIndexSha sha
 		return sha
@@ -363,6 +365,10 @@ set jl ru f c = do
 commitMessage :: Annex String
 commitMessage = fromMaybe "update" . annexCommitMessage <$> Annex.getGitConfig
 
+{- Commit message used when creating the branch. -}
+createMessage :: Annex String
+createMessage = fromMaybe "branch created" . annexCommitMessage <$> Annex.getGitConfig
+
 {- Stages the journal, and commits staged changes to the branch. -}
 commit :: String -> Annex ()
 commit = whenM (journalDirty gitAnnexJournalDir) . forceCommit

CHANGELOG

@@ -11,6 +11,8 @@ git-annex (8.20210429) UNRELEASED; urgency=medium
   * reinject: Error out when run on a file that is not annexed, rather
     than silently skipping it.
   * assistant: Fix a crash on startup by avoiding using forkProcess.
+  * init: When annex.commitmessage is set, use that message for the commit
+    that creates the git-annex branch.
 
  -- Joey Hess <id@joeyh.name>  Mon, 03 May 2021 10:33:10 -0400