sync: When in an adjusted branch, merge changes from the original branch

This causes changes to the original branch to get merged with a single
sync. Before, it took 2 syncs; the first happened to update the synced/
branch, and the second merged changes from the synced/ branch into the
ajusted branch.

Using mergeToAdjustedBranch when tomerge == origbranch is probably
overkill, but it does work fine.

Sponsored-By: the NIH-funded NICEMAN (ReproNim TR&D3) project

Annex/AdjustedBranch/Merge.hs

@@ -1,6 +1,6 @@
 {- adjusted branch merging
  -
- - Copyright 2016-2020 Joey Hess <id@joeyh.name>
+ - Copyright 2016-2023 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
@@ -8,6 +8,7 @@
 {-# LANGUAGE BangPatterns, OverloadedStrings #-}
 
 module Annex.AdjustedBranch.Merge (
+	canMergeToAdjustedBranch,
 	mergeToAdjustedBranch,
 ) where
 
@@ -32,6 +33,12 @@ import Utility.Directory.Create
 import qualified Data.ByteString as S
 import qualified System.FilePath.ByteString as P
 
+canMergeToAdjustedBranch :: Branch -> (OrigBranch, Adjustment) -> Annex Bool
+canMergeToAdjustedBranch tomerge (origbranch, adj) =
+	inRepo $ Git.Branch.changed currbranch tomerge
+  where
+	AdjBranch currbranch = originalToAdjusted origbranch adj
+
 {- Update the currently checked out adjusted branch, merging the provided
  - branch into it. Note that the provided branch should be a non-adjusted
  - branch. -}
@@ -42,16 +49,10 @@ mergeToAdjustedBranch tomerge (origbranch, adj) mergeconfig canresolvemerge comm
 	adjbranch@(AdjBranch currbranch) = originalToAdjusted origbranch adj
 	basis = basisBranch adjbranch
 
-	go commitsprevented =
-		ifM (inRepo $ Git.Branch.changed currbranch tomerge)
-			( do
-				(updatedorig, _) <- propigateAdjustedCommits'
-					False origbranch adj commitsprevented
-				changestomerge updatedorig
-			, nochangestomerge
-			)
-
-	nochangestomerge = return $ return True
+	go commitsprevented = do
+		(updatedorig, _) <- propigateAdjustedCommits'
+			False origbranch adj commitsprevented
+		changestomerge updatedorig
 
 	{- Since the adjusted branch changes files, merging tomerge
 	 - directly into it would likely result in unnecessary merge
@@ -98,7 +99,8 @@ mergeToAdjustedBranch tomerge (origbranch, adj) mergeconfig canresolvemerge comm
 				-- (for an unknown reason).
 				-- http://thread.gmane.org/gmane.comp.version-control.git/297237
 				inRepo $ Git.Command.run [Param "reset", Param "HEAD", Param "--quiet"]
-				showAction $ UnquotedString $ "Merging into " ++ fromRef (Git.Ref.base origbranch)
+				when (tomerge /= origbranch) $
+					showAction $ UnquotedString $ "Merging into " ++ fromRef (Git.Ref.base origbranch)
 				merged <- autoMergeFrom' tomerge Nothing mergeconfig commitmode True
 					(const $ resolveMerge (Just updatedorig) tomerge True)
 				if merged

Assistant/Threads/Merger.hs

@@ -99,7 +99,7 @@ onChange file
 						mc
 						def
 						cmode
-						changedbranch
+						[changedbranch]
 			recordCommit
 		| changedbranch == b =
 			-- Record commit so the pusher pushes it out.

Command/Merge.hs

@@ -62,7 +62,7 @@ mergeBranch o r = starting "merge" ai si $ do
 	currbranch <- getCurrentBranch
 	mc <- mergeConfig (allowUnrelatedHistories o)
 	let so = def { notOnlyAnnexOption = True }
-	next $ merge currbranch mc so Git.Branch.ManualCommit r
+	next $ merge currbranch mc so Git.Branch.ManualCommit [r]
   where
 	ai = ActionItemOther (Just (UnquotedString (Git.fromRef r)))
 	si = SeekInput []

Command/Sync.hs

@@ -351,14 +351,16 @@ mergeConfig mergeunrelated = do
 			else Nothing
 		]
 
-merge :: CurrBranch -> [Git.Merge.MergeConfig] -> SyncOptions -> Git.Branch.CommitMode -> Git.Branch -> Annex Bool
-merge currbranch mergeconfig o commitmode tomerge = do
+merge :: CurrBranch -> [Git.Merge.MergeConfig] -> SyncOptions -> Git.Branch.CommitMode -> [Git.Branch] -> Annex Bool
+merge currbranch mergeconfig o commitmode tomergel = do
 	canresolvemerge <- if resolveMergeOverride o
 		then getGitConfigVal annexResolveMerge
 		else return False
-	case currbranch of
-		(Just b, Just adj) -> mergeToAdjustedBranch tomerge (b, adj) mergeconfig canresolvemerge commitmode
-		(b, _) -> autoMergeFrom tomerge b mergeconfig commitmode canresolvemerge
+	and <$> case currbranch of
+		(Just b, Just adj) -> forM tomergel $ \tomerge ->
+			mergeToAdjustedBranch tomerge (b, adj) mergeconfig canresolvemerge commitmode
+		(b, _) -> forM tomergel $ \tomerge ->
+			autoMergeFrom tomerge b mergeconfig commitmode canresolvemerge
 
 syncBranch :: Git.Branch -> Git.Branch
 syncBranch = Git.Ref.underBase "refs/heads/synced" . origBranch
@@ -440,46 +442,54 @@ mergeLocal mergeconfig o currbranch = stopUnless (notOnlyAnnex o) $
 mergeLocal' :: [Git.Merge.MergeConfig] -> SyncOptions -> CurrBranch -> CommandStart
 mergeLocal' mergeconfig o currbranch@(Just branch, _) =
 	needMerge currbranch branch >>= \case
-		Nothing -> stop
-		Just syncbranch -> do
-			let ai = ActionItemOther (Just $ UnquotedString $ Git.Ref.describe syncbranch)
+		[] -> stop
+		tomerge -> do
+			let ai = ActionItemOther (Just $ UnquotedString $ unwords $ map Git.Ref.describe tomerge)
 			let si = SeekInput []
 			starting "merge" ai si $
-				next $ merge currbranch mergeconfig o Git.Branch.ManualCommit syncbranch
+				next $ merge currbranch mergeconfig o Git.Branch.ManualCommit tomerge
 mergeLocal' _ _ currbranch@(Nothing, _) = inRepo Git.Branch.currentUnsafe >>= \case
 	Just branch -> needMerge currbranch branch >>= \case
-		Nothing -> stop
-		Just syncbranch -> do
-			let ai = ActionItemOther (Just $ UnquotedString $ Git.Ref.describe syncbranch)
+		[] -> stop
+		tomerge -> do
+			let ai = ActionItemOther (Just $ UnquotedString $ unwords $ map Git.Ref.describe tomerge)
 			let si = SeekInput []
 			starting "merge" ai si $ do
-				warning $ UnquotedString $ "There are no commits yet to branch " ++ Git.fromRef branch ++ ", so cannot merge " ++ Git.fromRef syncbranch ++ " into it."
+				warning $ UnquotedString $ "There are no commits yet to branch " ++ Git.fromRef branch ++ ", so cannot merge " ++ unwords (map Git.fromRef tomerge) ++ " into it."
 				next $ return False
 	Nothing -> stop
 
--- Returns the branch that should be merged, if any.
-needMerge :: CurrBranch -> Git.Branch -> Annex (Maybe Git.Branch)
+-- Returns the branches that should be merged, if any.
+--
+-- Usually this is the sync branch. However, when in an adjusted branch,
+-- it can be either the sync branch or the original branch, or both.
+needMerge :: CurrBranch -> Git.Branch -> Annex [Git.Branch]
 needMerge currbranch headbranch
-	| is_branchView headbranch = return Nothing
-	| otherwise = 
-		ifM (allM id checks)
-			( return (Just syncbranch)
-			, return Nothing
-			)
+	| is_branchView headbranch = return []
+	| otherwise = ifM isBareRepo
+		( return []
+		, do
+			syncbranchret <- usewhen syncbranch syncbranchchecks
+			adjbranchret <- case currbranch of
+				(Just origbranch, Just adj) -> 
+					usewhen origbranch $
+						canMergeToAdjustedBranch origbranch (origbranch, adj)
+				_ -> return []
+			return (syncbranchret++adjbranchret)
+		)
   where
+	usewhen v c = ifM c
+		( return [v]
+		, return []
+		)
 	syncbranch = syncBranch headbranch
-	checks = case currbranch of
-		(Just _, madj) -> 
-			let branch' = maybe headbranch (adjBranch . originalToAdjusted headbranch) madj
-			in 
-				[ not <$> isBareRepo
-				, inRepo (Git.Ref.exists syncbranch)
-				, inRepo (Git.Branch.changed branch' syncbranch)
-				]
-		(Nothing, _) ->
-			[ not <$> isBareRepo
-			, inRepo (Git.Ref.exists syncbranch)
-			]
+	syncbranchchecks = case currbranch of
+		(Just _, madj) -> syncbranchchanged madj
+		(Nothing, _) -> hassyncbranch
+	hassyncbranch = inRepo (Git.Ref.exists syncbranch)
+	syncbranchchanged madj =
+		let branch' = maybe headbranch (adjBranch . originalToAdjusted headbranch) madj
+		in hassyncbranch <&&> inRepo (Git.Branch.changed branch' syncbranch)
 
 pushLocal :: SyncOptions -> CurrBranch -> CommandStart
 pushLocal o b = stopUnless (notOnlyAnnex o) $ do
@@ -631,8 +641,9 @@ mergeRemote remote currbranch mergeconfig o = ifM isBareRepo
 			mergelisted (tomerge (branchlist (Just branch)))
 	)
   where
-	mergelisted getlist = and <$> 
-		(mapM (merge currbranch mergeconfig o Git.Branch.ManualCommit . remoteBranch remote) =<< getlist)
+	mergelisted getlist =
+		merge currbranch mergeconfig o Git.Branch.ManualCommit
+			=<< map (remoteBranch remote) <$> getlist
 	tomerge = filterM (changed remote)
 	branchlist Nothing = []
 	branchlist (Just branch)

doc/bugs/annex_sync_silently_resets_master_to_previous_sync.mdwn

@@ -22,3 +22,5 @@ PS investigation of adjusted/unlocked came up in ReproNim context where people w
 
 [[!meta author=yoh]]
 [[!tag projects/repronim]]
+
+> [[fixed|done]] --[[Joey]]

doc/bugs/annex_sync_silently_resets_master_to_previous_sync/comment_3_80d241b2654856669d82d1ab5de40c00._comment

@@ -0,0 +1,8 @@
+[[!comment format=mdwn
+ username="joey"
+ subject="""comment 3"""
+ date="2023-07-06T16:16:36Z"
+ content="""
+Ok, fixed git-annex sync to immediately merge the changes from the original
+branch into the adjusted branch.
+"""]]