adjusted branches need git 2.2.0 or newer

When git-annex is used with a git version older than 2.2.0, disable support for
adjusted branches, since GIT_COMMON_DIR is needed to update them and was first
added in that version of git.

Annex/AdjustedBranch.hs

@@ -21,6 +21,8 @@ module Annex.AdjustedBranch (
 	updateAdjustedBranch,
 	propigateAdjustedCommits,
 	checkAdjustedClone,
+	isGitVersionSupported,
+	checkVersionSupported,
 ) where
 
 import Annex.Common
@@ -39,6 +41,8 @@ import Git.Env
 import Git.Index
 import Git.FilePath
 import qualified Git.LockFile
+import qualified Git.Version
+import Annex.Version
 import Annex.CatFile
 import Annex.Link
 import Annex.AutoMerge
@@ -507,3 +511,15 @@ checkAdjustedClone = go =<< inRepo Git.Branch.current
 				setBasisBranch basis remotebranch
 			unlessM (inRepo $ Git.Ref.exists origbranch) $
 				inRepo $ Git.Branch.update' origbranch remotebranch
+
+-- git 2.2.0 needed for GIT_COMMON_DIR which is needed
+-- by updateAdjustedBranch to use withWorkTreeRelated.
+isGitVersionSupported :: IO Bool
+isGitVersionSupported = not <$> Git.Version.older "2.2.0"
+
+checkVersionSupported :: Annex ()
+checkVersionSupported = do
+	unlessM versionSupportsAdjustedBranch $
+		error "Adjusted branches are only supported in v6 or newer repositories."
+	unlessM (liftIO isGitVersionSupported) $
+		error "Your version of git is too old; upgrade it to 2.2.0 or newer to use adjusted branches."

Annex/GitOverlay.hs

@@ -40,7 +40,10 @@ withWorkTree d = withAltRepo
  - files that are related to the work tree coming from an overlay
  - directory other than the usual. This is done by pointing
  - GIT_COMMON_DIR at the regular git directory, and GIT_DIR at the
- - overlay directory. -}
+ - overlay directory.
+ -
+ - Needs git 2.2.0 or newer.
+ -}
 withWorkTreeRelated :: FilePath -> Annex a -> Annex a
 withWorkTreeRelated d = withAltRepo modrepo unmodrepo
   where

Command/Adjust.hs

@@ -9,7 +9,6 @@ module Command.Adjust where
 
 import Command
 import Annex.AdjustedBranch
-import Annex.Version
 
 cmd :: Command
 cmd = notBareRepo $ notDirect $ noDaemonRunning $
@@ -34,8 +33,7 @@ seek = commandAction . start
 
 start :: Adjustment -> CommandStart
 start adj = do
-	unlessM versionSupportsAdjustedBranch $
+	checkVersionSupported
-		error "Adjusted branches are only supported in v6 or newer repositories."
 	showStart "adjust" ""
 	enterAdjustedBranch adj
 	next $ next $ return True

Test.hs

@@ -72,6 +72,7 @@ import qualified Annex.Link
 import qualified Annex.Init
 import qualified Annex.CatFile
 import qualified Annex.Path
+import qualified Annex.AdjustedBranch
 import qualified Annex.View
 import qualified Annex.View.ViewedFile
 import qualified Logs.View
@@ -1048,7 +1049,7 @@ test_conflict_resolution =
 
 {- Conflict resolution while in an adjusted branch. -}
 test_conflict_resolution_adjusted_branch :: Assertion
-test_conflict_resolution_adjusted_branch = 
+test_conflict_resolution_adjusted_branch = whenM Annex.AdjustedBranch.isGitVersionSupported $
 	withtmpclonerepo $ \r1 ->
 		withtmpclonerepo $ \r2 -> do
 			indir r1 $ do

debian/changelog

@@ -6,11 +6,16 @@ git-annex (6.20160419) UNRELEASED; urgency=medium
     fixed to not hang when it cannot find locale files.
   * reinject: When src file's content cannot be verified, leave it alone,
     instead of deleting it.
+  * reinject: Added new mode which can reinject known files into the annex.
+    For example: git-annex reinject --known /mnt/backup/*
   * calckey: New plumbing command, calculates the key that would be used
     to refer to a file.
   * Fix bug that prevented annex.sshcaching=false configuration from taking
     effect when on a crippled filesystem. Thanks, divergentdave.
   * Isolate test suite from global git config settings.
+  * When git-annex is used with a git version older than 2.2.0, disable
+    support for adjusted branches, since GIT_COMMON_DIR is needed to update
+    them and was first added in that version of git.
 
  -- Joey Hess <id@joeyh.name>  Tue, 19 Apr 2016 12:57:15 -0400