XMPP: Avoid redundant and unncessary pushes. Note that this breaks compatibility with previous versions of git-annex, which will refuse to accept any XMPP pushes from this version.

Git/Branch.hs

@@ -13,6 +13,7 @@ import Common
 import Git
 import Git.Sha
 import Git.Command
+import Git.Ref (headRef)
 
 {- The currently checked out branch.
  -
@@ -35,7 +36,7 @@ current r = do
 {- The current branch, which may not really exist yet. -}
 currentUnsafe :: Repo -> IO (Maybe Git.Ref)
 currentUnsafe r = parse . firstLine
-	<$> pipeReadStrict [Param "symbolic-ref", Param "HEAD"] r
+	<$> pipeReadStrict [Param "symbolic-ref", Param $ show headRef] r
   where
 	parse l
 		| null l = Nothing

Git/DiffTree.hs

@@ -46,7 +46,10 @@ diffTreeRecursive src dst = getdiff (Param "diff-tree")
 diffIndex :: Repo -> IO ([DiffTreeItem], IO Bool)
 diffIndex repo = do
 	ifM (Git.Ref.headExists repo)
-		( getdiff (Param "diff-index") [Param "--cached", Param "HEAD"] repo
+		( getdiff (Param "diff-index")
+			[ Param "--cached"
+			, Param $ show Git.Ref.headRef
+			] repo
 		, return ([], return True)
 		)
 

Git/Ref.hs

@@ -1,6 +1,6 @@
 {- git ref stuff
  -
- - Copyright 2011 Joey Hess <joey@kitenet.net>
+ - Copyright 2011-2013 Joey Hess <joey@kitenet.net>
  -
  - Licensed under the GNU GPL version 3 or higher.
  -}
@@ -13,6 +13,9 @@ import Git.Command
 
 import Data.Char (chr)
 
+headRef :: Ref
+headRef = Ref "HEAD"
+
 {- Converts a fully qualified git ref into a user-visible string. -}
 describe :: Ref -> String
 describe = show . base
@@ -54,18 +57,18 @@ sha branch repo = process <$> showref repo
 	process [] = Nothing
 	process s = Just $ Ref $ firstLine s
 
-{- List of (refs, branches) matching a given ref spec. -}
-matching :: Ref -> Repo -> IO [(Ref, Branch)]
-matching ref repo = map gen . lines <$> 
-	pipeReadStrict [Param "show-ref", Param $ show ref] repo
+{- List of (shas, branches) matching a given ref or refs. -}
+matching :: [Ref] -> Repo -> IO [(Sha, Branch)]
+matching refs repo = map gen . lines <$> 
+	pipeReadStrict (Param "show-ref" : map (Param . show) refs) repo
   where
 	gen l = let (r, b) = separate (== ' ') l
 		in (Ref r, Ref b)
 
-{- List of (refs, branches) matching a given ref spec.
- - Duplicate refs are filtered out. -}
-matchingUniq :: Ref -> Repo -> IO [(Ref, Branch)]
-matchingUniq ref repo = nubBy uniqref <$> matching ref repo
+{- List of (shas, branches) matching a given ref spec.
+ - Duplicate shas are filtered out. -}
+matchingUniq :: [Ref] -> Repo -> IO [(Sha, Branch)]
+matchingUniq refs repo = nubBy uniqref <$> matching refs repo
   where
 	uniqref (a, _) (b, _) = a == b
 

Git/Types.hs

@@ -41,7 +41,7 @@ data Repo = Repo
 
 {- A git ref. Can be a sha1, or a branch or tag name. -}
 newtype Ref = Ref String
-	deriving (Eq)
+	deriving (Eq, Ord)
 
 instance Show Ref where
 	show (Ref v) = v