sync --content: Fix dropping unwanted content from the local repository

This fixes a bug with the numcopies counting when using sync --content.
It did not always pass the local repo uuid to handleDropsFrom, and so the
numcopies counting was off by one, and unwanted local content would only be
dropped when there were numcopies+1 remote copies.

Also, support dropping local content that has reached an
exporttree remote that is not untrusted (currently only S3 remotes
with versioning).

Annex/Drop.hs

@@ -11,11 +11,12 @@ import Annex.Common
 import qualified Annex
 import Logs.Trust
 import Annex.NumCopies
-import Types.Remote (uuid, appendonly)
+import Types.Remote (uuid, appendonly, config)
 import qualified Remote
 import qualified Command.Drop
 import Command
 import Annex.Wanted
+import Annex.Export
 import Config
 import Annex.Content.Direct
 import qualified Database.Keys
@@ -30,7 +31,8 @@ type Reason = String
  - and numcopies settings.
  -
  - Skips trying to drop from remotes that are appendonly, since those drops
- - would presumably fail.
+ - would presumably fail. Also skips dropping from exporttree remotes,
+ - which don't allow dropping individual keys.
  -
  - The UUIDs are ones where the content is believed to be present.
  - The Remote list can include other remotes that do not have the content;
@@ -61,10 +63,9 @@ handleDropsFrom locs rs reason fromhere key afile preverified runner = do
 		AssociatedFile (Just f) -> nub (f : l)
 		AssociatedFile Nothing -> l
 	n <- getcopies fs
-	let rs' = filter (not . appendonly) rs
 	void $ if fromhere && checkcopies n Nothing
-		then go fs rs' n >>= dropl fs
-		else go fs rs' n
+		then go fs rs n >>= dropl fs
+		else go fs rs n
   where
 	getcopies fs = do
 		(untrusted, have) <- trustPartition UnTrusted locs
@@ -91,6 +92,8 @@ handleDropsFrom locs rs reason fromhere key afile preverified runner = do
 	go _ [] n = pure n
 	go fs (r:rest) n
 		| uuid r `S.notMember` slocs = go fs rest n
+		| appendonly r = go fs rest n
+		| exportTree (config r) = go fs rest n
 		| checkcopies n (Just $ Remote.uuid r) =
 			dropr fs r n >>= go fs rest
 		| otherwise = pure n

CHANGELOG

@@ -1,3 +1,12 @@
+git-annex (7.20181212) UNRELEASED; urgency=medium
+
+  * sync --content: Fix dropping unwanted content from the local repository.
+  * sync --content: Support dropping local content that has reached an
+    exporttree remote that is not untrusted (currently only S3 remotes
+    with versioning).
+
+ -- Joey Hess <id@joeyh.name>  Tue, 18 Dec 2018 12:24:52 -0400
+
 git-annex (7.20181211) upstream; urgency=medium
 
   * S3: Improve diagnostics when a remote is configured with exporttree and

Command/Sync.hs

@@ -166,9 +166,9 @@ seek o = allowConcurrentOutput $ do
 
 	remotes <- syncRemotes (syncWith o)
 	let gitremotes = filter Remote.gitSyncableRemote remotes
-	(exportremotes, dataremotes) <- partition (exportTree . Remote.config)
-		. filter (\r -> Remote.uuid r /= NoUUID)
+	dataremotes <- filter (\r -> Remote.uuid r /= NoUUID)
 		<$> filterM (not <$$> liftIO . getDynamicConfig . remoteAnnexIgnore . Remote.gitconfig) remotes
+	let exportremotes = filter (exportTree . Remote.config) dataremotes
 
 	if cleanupOption o
 		then do
@@ -187,8 +187,11 @@ seek o = allowConcurrentOutput $ do
 				]
 			
 			whenM shouldsynccontent $ do
-				syncedcontent <- withbranch $ seekSyncContent o dataremotes
+				-- Send content to any exports first, in 
+				-- case that lets content be dropped from
+				-- other repositories.
 				exportedcontent <- withbranch $ seekExportContent exportremotes
+				syncedcontent <- withbranch $ seekSyncContent o dataremotes
 				-- Transferring content can take a while,
 				-- and other changes can be pushed to the
 				-- git-annex branch on the remotes in the
@@ -618,14 +621,15 @@ seekSyncContent o rs currbranch = do
  -}
 syncFile :: Either (Maybe (Bloom Key)) (Key -> Annex ()) -> [Remote] -> AssociatedFile -> Key -> Annex Bool
 syncFile ebloom rs af k = onlyActionOn' k $ do
+	inhere <- inAnnex k
 	locs <- map Remote.uuid <$> Remote.keyPossibilities k
 	let (have, lack) = partition (\r -> Remote.uuid r `elem` locs) rs
 
-	got <- anyM id =<< handleget have
+	got <- anyM id =<< handleget have inhere
 	putrs <- handleput lack
 
 	u <- getUUID
-	let locs' = concat [[u | got], putrs, locs]
+	let locs' = concat [if inhere || got then [u] else [], putrs, locs]
 
 	-- A bloom filter is populated with all the keys in the first pass.
 	-- On the second pass, avoid dropping keys that were seen in the
@@ -649,12 +653,12 @@ syncFile ebloom rs af k = onlyActionOn' k $ do
 	
 	return (got || not (null putrs))
   where
-	wantget have = allM id 
+	wantget have inhere = allM id 
 		[ pure (not $ null have)
-		, not <$> inAnnex k
+		, pure (not inhere)
 		, wantGet True (Just k) af
 		]
-	handleget have = ifM (wantget have)
+	handleget have inhere = ifM (wantget have inhere)
 		( return [ get have ]
 		, return []
 		)

doc/bugs/sync_does_not_drop_local_content_present_in_exporttree_remote.mdwn

@@ -4,3 +4,10 @@ has been transferred to an exporttree remote.
 This normally doesn't matter since exporttree remotes are untrusted, but
 S3 with versioning enabled is not untrusted and once a file reaches such a
 remote it should be able to be dropped locally. --[[Joey]]
+
+Actually, there are two bugs here, because sync --content also fails to
+drop local unwanted content that's got only 1 copy on another remote.
+It forgot to include the local copy as a currently present copy, throwing
+off the numcopies counting. --[[Joey]]
+
+Both [fixed|done]] --[[Joey]]