handle case of adding populated drive to just created repo

The just created repo has no master branch commits yet. This is now
handled, merging in the master branch from the populated drive.

1 files changed, 17 insertions, 7 deletions

diff --git a/Git/Branch.hs b/Git/Branch.hs
index 098aa1a1a..f73ae5e2a 100644
--- a/Git/Branch.hs
+++ b/Git/Branch.hs
@@ -23,13 +23,23 @@ import Git.Command
  -}
 current :: Repo -> IO (Maybe Git.Ref)
 current r = do
-	branch <- firstLine <$> pipeRead [Param "symbolic-ref", Param "HEAD"] r
-	if null branch
-		then return Nothing
-		else ifM (null <$> pipeRead [Param "show-ref", Param branch] r)
-			( return Nothing
-			, return $ Just $ Git.Ref branch
-			)
+	v <- currentUnsafe r
+	case v of
+		Nothing -> return Nothing
+		Just branch -> 
+			ifM (null <$> pipeRead [Param "show-ref", Param $ show branch] r)
+				( return Nothing
+				, return v
+				)
+
+{- The current branch, which may not really exist yet. -}
+currentUnsafe :: Repo -> IO (Maybe Git.Ref)
+currentUnsafe r = parse . firstLine
+	<$> pipeRead [Param "symbolic-ref", Param "HEAD"] r
+	where
+		parse l
+			| null l = Nothing
+			| otherwise = Just $ Git.Ref l
 
 {- Checks if the second branch has any commits not present on the first
  - branch. -}