synthesize RmChange when a directory is deleted

This gets directory renames closer to being fully detected.
There's close to no extra overhead to doing it this way.

3 files changed, 26 insertions, 13 deletions

diff --git a/Assistant/Threads/Committer.hs b/Assistant/Threads/Committer.hs
index f1e26f9aa..0d9010cb7 100644
--- a/Assistant/Threads/Committer.hs
+++ b/Assistant/Threads/Committer.hs
@@ -80,7 +80,7 @@ waitChangeTime a = runEvery (Seconds 1) <~> do
 	changes <- getChanges
 	-- See if now's a good time to commit.
 	now <- liftIO getCurrentTime
-	case (shouldCommit now changes, lonelychange changes) of
+	case (shouldCommit now changes, possiblyrename changes) of
 		(True, False) -> a (changes, now)
 		(True, True) -> do
 			-- Wait for other, related changes to arrive.
@@ -92,10 +92,13 @@ waitChangeTime a = runEvery (Seconds 1) <~> do
 		_ -> refill changes
   where
 	{- Did we perhaps only get one of the AddChange and RmChange pair
-	 - that make up a rename? -}
-	lonelychange [(PendingAddChange _ _)] = True
-	lonelychange [c] | isRmChange c = True
-	lonelychange _ = False
+	 - that make up a file rename? Or some of the pairs that make up 
+	 - a directory rename?
+	 -}
+	possiblyrename cs = all renamepart cs
+
+	renamepart (PendingAddChange _ _) = True
+	renamepart c = isRmChange c
 
 isRmChange :: Change -> Bool
 isRmChange (Change { changeInfo = i }) | i == RmChange = True
diff --git a/Assistant/Threads/Watcher.hs b/Assistant/Threads/Watcher.hs
index 0f76c6a4c..8d06e6659 100644
--- a/Assistant/Threads/Watcher.hs
+++ b/Assistant/Threads/Watcher.hs
@@ -43,6 +43,7 @@ import Data.Bits.Utils
 import Data.Typeable
 import qualified Data.ByteString.Lazy as L
 import qualified Control.Exception as E
+import Data.Time.Clock
 
 checkCanWatch :: Annex ()
 checkCanWatch
@@ -251,17 +252,26 @@ onDel file _ = do
 
 {- A directory has been deleted, or moved, so tell git to remove anything
  - that was inside it from its cache. Since it could reappear at any time,
- - use --cached to only delete it from the index. 
+ - use --cached to only delete it from the index.
  -
- - Note: This could use unstageFile, but would need to run another git
- - command to get the recursive list of files in the directory, so rm is
- - just as good. -}
+ - This queues up a lot of RmChanges, which assists the Committer in
+ - pairing up renamed files when the directory was renamed. -}
 onDelDir :: Handler
 onDelDir dir _ = do
 	debug ["directory deleted", dir]
-	liftAnnex $ Annex.Queue.addCommand "rm"
-		[Params "--quiet -r --cached --ignore-unmatch --"] [dir]
-	madeChange dir RmDirChange
+	(fs, clean) <- liftAnnex $ inRepo $ LsFiles.deleted [dir]
+
+	liftAnnex $ forM_ fs $ \f -> Annex.Queue.addUpdateIndex =<<
+		inRepo (Git.UpdateIndex.unstageFile f)
+
+	-- Get the events queued up as fast as possible, so the
+	-- committer sees them all in one block.
+	now <- liftIO getCurrentTime
+	forM_ fs $ \f -> recordChange $ Change now f RmChange
+
+	void $ liftIO $ clean
+	liftAnnex $ Annex.Queue.flushWhenFull
+	noChange
 
 {- Called when there's an error with inotify or kqueue. -}
 onErr :: Handler
diff --git a/Assistant/Types/Changes.hs b/Assistant/Types/Changes.hs
index 9f0aad7a7..651085947 100644
--- a/Assistant/Types/Changes.hs
+++ b/Assistant/Types/Changes.hs
@@ -14,7 +14,7 @@ import Utility.TSet
 import Data.Time.Clock
 import Control.Concurrent.STM
 
-data ChangeInfo = AddChange Key | LinkChange (Maybe Key) | RmChange | RmDirChange
+data ChangeInfo = AddChange Key | LinkChange (Maybe Key) | RmChange
 	deriving (Show, Eq)
 
 changeInfoKey :: ChangeInfo -> Maybe Key