assistant: Deal with upcoming git's refusal to merge unrelated histories by default

git 2.8.1 (or perhaps 2.9.0) is going to prevent git merge from merging in
unrelated branches. Since the webapp's pairing etc features often combine
together repositories with unrelated histories, work around this behavior
change by setting GIT_MERGE_ALLOW_UNRELATED_HISTORIES when the assistant
merges.

Note though that this is not done for git annex sync's merges, so
it will follow git's default or configured behavior.

1 files changed, 8 insertions, 9 deletions

diff --git a/Annex/Direct.hs b/Annex/Direct.hs
index 782803e71..5724d1162 100644
--- a/Annex/Direct.hs
+++ b/Annex/Direct.hs
@@ -162,8 +162,8 @@ addDirect file cache = do
  - file. This is the same as what git does when updating the index
  - normally.
  -}
-mergeDirect :: Maybe Git.Ref -> Maybe Git.Ref -> Git.Branch -> Annex Bool -> Git.Branch.CommitMode -> Annex Bool
-mergeDirect startbranch oldref branch resolvemerge commitmode = exclusively $ do
+mergeDirect :: Maybe Git.Ref -> Maybe Git.Ref -> Git.Branch -> Annex Bool -> [Git.Merge.MergeConfig] -> Git.Branch.CommitMode -> Annex Bool
+mergeDirect startbranch oldref branch resolvemerge mergeconfig commitmode = exclusively $ do
 	reali <- liftIO . absPath =<< fromRepo indexFile
 	tmpi <- liftIO . absPath =<< fromRepo indexFileLock
 	liftIO $ whenM (doesFileExist reali) $
@@ -176,7 +176,7 @@ mergeDirect startbranch oldref branch resolvemerge commitmode = exclusively $ do
 		createDirectoryIfMissing True d
 
 	withIndexFile tmpi $ do
-		merged <- stageMerge d branch commitmode
+		merged <- stageMerge d branch mergeconfig commitmode
 		ok <- if merged
 			then return True
 			else resolvemerge
@@ -195,19 +195,18 @@ mergeDirect startbranch oldref branch resolvemerge commitmode = exclusively $ do
 
 {- Stage a merge into the index, avoiding changing HEAD or the current
  - branch. -}
-stageMerge :: FilePath -> Git.Branch -> Git.Branch.CommitMode -> Annex Bool
-stageMerge d branch commitmode = do
+stageMerge :: FilePath -> Git.Branch -> [Git.Merge.MergeConfig] -> Git.Branch.CommitMode -> Annex Bool
+stageMerge d branch mergeconfig commitmode = do
 	-- XXX A bug in git makes stageMerge unsafe to use if the git repo
 	-- is configured with core.symlinks=false
-	-- Using mergeNonInteractive is not ideal though, since it will
+	-- Using merge is not ideal though, since it will
 	-- update the current branch immediately, before the work tree
 	-- has been updated, which would leave things in an inconsistent
 	-- state if mergeDirectCleanup is interrupted.
 	-- <http://marc.info/?l=git&m=140262402204212&w=2>
-	liftIO $ print ("stagemerge in", d)
 	merger <- ifM (coreSymlinks <$> Annex.getGitConfig)
-		( return Git.Merge.stageMerge
-		, return $ \ref -> Git.Merge.mergeNonInteractive ref commitmode
+		( return $ \ref -> Git.Merge.stageMerge ref mergeconfig
+		, return $ \ref -> Git.Merge.merge ref mergeconfig commitmode
 		)
 	inRepo $ \g -> do
 		wd <- liftIO $ absPath d