clean up url removal presence update

* rmurl: Fix a case where removing the last url left git-annex thinking
  content was still present in the web special remote.
* SETURLPRESENT, SETURIPRESENT, SETURLMISSING, and SETURIMISSING
  used to update the presence information of the external special remote
  that called them; this was not documented behavior and is no longer done.

Done by making setUrlPresent and setUrlMissing only update presence info
for the web, and only when the url is a web url. See the comment for
reasoning about why that's the right thing to do.

In AddUrl, had to make it update location tracking, to handle the
non-web-url case.

This commit was sponsored by Ewen McNeill on Patreon.

Assistant/Upgrade.hs

@@ -83,7 +83,7 @@ startDistributionDownload d = go =<< liftIO . newVersionLocation d =<< liftIO ol
   where
 	go Nothing = debug ["Skipping redundant upgrade"]
 	go (Just dest) = do
-		liftAnnex $ setUrlPresent webUUID k u
+		liftAnnex $ setUrlPresent k u
 		hook <- asIO1 $ distributionDownloadComplete d dest cleanup
 		modifyDaemonStatus_ $ \s -> s
 			{ transferHook = M.insert k hook (transferHook s) }
@@ -100,7 +100,7 @@ startDistributionDownload d = go =<< liftIO . newVersionLocation d =<< liftIO ol
 		}
 	cleanup = liftAnnex $ do
 		lockContentForRemoval k removeAnnex
-		setUrlMissing webUUID k u
+		setUrlMissing k u
 		logStatus k InfoMissing
 
 {- Called once the download is done.

CHANGELOG

@@ -5,6 +5,11 @@ git-annex (6.20180927) UNRELEASED; urgency=medium
   * Improve display when git config download from a http remote fails.
   * Added annex.jobs setting, which is like using the -J option.
   * Fix reversion in support of annex.web-options.
+  * rmurl: Fix a case where removing the last url left git-annex thinking
+    content was still present in the web special remote.
+  * SETURLPRESENT, SETURIPRESENT, SETURLMISSING, and SETURIMISSING
+    used to update the presence information of the external special remote
+    that called them; this was not documented behavior and is no longer done.
 
  -- Joey Hess <id@joeyh.name>  Thu, 27 Sep 2018 15:27:20 -0400
 

Command/AddUrl.hs

@@ -233,7 +233,8 @@ addUrlChecked o url file u checkexistssize key =
 			(exists, samesize, url') <- checkexistssize key
 			if exists && (samesize || relaxedOption (downloadOptions o))
 				then do
-					setUrlPresent u key url'
+					setUrlPresent key url'
+					logChange key u InfoPresent
 					next $ return True
 				else do
 					warning $ "while adding a new url to an already annexed file, " ++ if exists
@@ -397,7 +398,8 @@ addWorkTree u url file key mtmp = case mtmp of
   where
 	go = do
 		maybeShowJSON $ JSONChunk [("key", key2file key)]
-		setUrlPresent u key url
+		setUrlPresent key url
+		logChange key u InfoPresent
 		ifM (addAnnexedFile file key mtmp)
 			( do
 				when (isJust mtmp) $

Command/Migrate.hs

@@ -17,7 +17,6 @@ import qualified Command.Fsck
 import qualified Annex
 import Logs.MetaData
 import Logs.Web
-import qualified Remote
 
 cmd :: Command
 cmd = notDirect $ withGlobalOptions [annexedMatchingOptions] $
@@ -78,9 +77,8 @@ perform file oldkey oldbackend newbackend = go =<< genkey (fastMigrate oldbacken
 			-- If the old key had some associated urls, record them for
 			-- the new key as well.
 			urls <- getUrls oldkey
-			forM_ urls $ \url -> do
-				r <- Remote.claimingUrl url
-				setUrlPresent (Remote.uuid r) newkey url
+			forM_ urls $ \url ->
+				setUrlPresent newkey url
 			next $ Command.ReKey.cleanup file oldkey newkey
 		, error "failed"
 		)

Command/RegisterUrl.hs

@@ -69,5 +69,5 @@ perform key url = do
 perform' :: Key -> URLString -> Annex Bool
 perform' key url = do
 	r <- Remote.claimingUrl url
-	setUrlPresent (Remote.uuid r) key (setDownloader' url r)
+	setUrlPresent key (setDownloader' url r)
 	return True

Command/RmUrl.hs

@@ -49,5 +49,5 @@ start (file, url) = flip whenAnnexed file $ \_ key -> do
 cleanup :: String -> Key -> CommandCleanup
 cleanup url key = do
 	r <- Remote.claimingUrl url
-	setUrlMissing (Remote.uuid r) key (setDownloader' url r)
+	setUrlMissing key (setDownloader' url r)
 	return True

Logs/Web.hs

@@ -56,20 +56,32 @@ getUrlsWithPrefix key prefix = filter (prefix `isPrefixOf`)
 	. map (fst . getDownloader)
 	<$> getUrls key
 
-setUrlPresent :: UUID -> Key -> URLString -> Annex ()
-setUrlPresent uuid key url = do
+setUrlPresent :: Key -> URLString -> Annex ()
+setUrlPresent key url = do
 	us <- getUrls key
 	unless (url `elem` us) $ do
 		config <- Annex.getGitConfig
 		addLog (urlLogFile config key) =<< logNow InfoPresent url
-	logChange key uuid InfoPresent
+	-- If the url does not have an OtherDownloader, it must be present
+	-- in the web.
+	case snd (getDownloader url) of
+		OtherDownloader -> return ()
+		_ -> logChange key webUUID InfoPresent
 
-setUrlMissing :: UUID -> Key -> URLString -> Annex ()
-setUrlMissing uuid key url = do
+setUrlMissing :: Key -> URLString -> Annex ()
+setUrlMissing key url = do
 	config <- Annex.getGitConfig
 	addLog (urlLogFile config key) =<< logNow InfoMissing url
-	whenM (null <$> getUrls key) $
-		logChange key uuid InfoMissing
+	-- If the url was a web url (not OtherDownloader) and none of
+	-- the remaining urls for the key are web urls, the key must not
+	-- be present in the web.
+	when (isweb url) $
+		whenM (null . filter isweb <$> getUrls key) $
+			logChange key webUUID InfoMissing
+  where
+	isweb u = case snd (getDownloader u) of
+		OtherDownloader -> False
+		_ -> True
 
 {- Finds all known urls. -}
 knownUrls :: Annex [(Key, URLString)]

Remote/BitTorrent.hs

@@ -112,7 +112,7 @@ uploadKey _ _ _ = do
 
 dropKey :: Key -> Annex Bool
 dropKey k = do
-	mapM_ (setUrlMissing bitTorrentUUID k) =<< getBitTorrentUrls k
+	mapM_ (setUrlMissing k) =<< getBitTorrentUrls k
 	return True
 
 {- We punt and don't try to check if a torrent has enough seeders

Remote/External.hs

@@ -416,9 +416,9 @@ handleRequest' st external req mp responsehandler
 			<$> getRemoteState (externalUUID external) key
 		send $ VALUE state
 	handleRemoteRequest (SETURLPRESENT key url) =
-		setUrlPresent (externalUUID external) key url
+		setUrlPresent key url
 	handleRemoteRequest (SETURLMISSING key url) =
-		setUrlMissing (externalUUID external) key url
+		setUrlMissing key url
 	handleRemoteRequest (SETURIPRESENT key uri) =
 		withurl (SETURLPRESENT key) uri
 	handleRemoteRequest (SETURIMISSING key uri) =

Remote/S3.hs

@@ -195,7 +195,7 @@ store _r info h = fileStorer $ \k f p -> do
 	void $ storeHelper info h f (T.pack $ bucketObject info k) p
 	-- Store public URL to item in Internet Archive.
 	when (isIA info && not (isChunkKey k)) $
-		setUrlPresent webUUID k (iaPublicUrl info (bucketObject info k))
+		setUrlPresent k (iaPublicUrl info (bucketObject info k))
 	return True
 
 storeHelper :: S3Info -> S3Handle -> FilePath -> S3.Object -> MeterUpdate -> Annex (Maybe S3VersionID)

Remote/Web.hs

@@ -100,7 +100,7 @@ uploadKey _ _ _ = do
 
 dropKey :: Key -> Annex Bool
 dropKey k = do
-	mapM_ (setUrlMissing webUUID k) =<< getWebUrls k
+	mapM_ (setUrlMissing k) =<< getWebUrls k
 	return True
 
 checkKey :: Key -> Annex Bool

doc/bugs/suggests_to_enable_web_remote_even_when_there_is_no_web_urls_for_the_file.mdwn

@@ -39,4 +39,4 @@ ok
 
 [[!meta name=yoh]]
 
-> closing as yoh says "nothing to fix" [[done]] --[[Joey]]
+> I think I've now understood and fixed this, so [[done]] --[[Joey]]

doc/bugs/suggests_to_enable_web_remote_even_when_there_is_no_web_urls_for_the_file/comment_4_6dff7befbaacbff573c5f72688966af5._comment

@@ -0,0 +1,35 @@
+[[!comment format=mdwn
+ username="joey"
+ subject="""comment 4"""
+ date="2018-10-04T20:20:43Z"
+ content="""
+I think that making rmurl filter out urls with an OtherDownloader
+when removing an url claimed by the web is sufficient.
+Then SETURIPRESENT won't confuse rmurl from the web.
+
+But what about SETURLPRESENT? Well, that url ought to be a url that can be
+downloaded by the web special remote. And if the web special remote is marked
+as present, it will try to download from that url along with whatever other urls
+are recorded. So, it makes sense for rmurl to treat that url as an indication
+that the web still has content, when removing some other url.
+
+But then if an url is added to the web, and then an external special remote
+uses SETURLPRESENT with another url, and then rmurl removes the first url,
+and then SETURLMISSING removes the other url, the content will still be marked
+as present in the web. So it seem that SETURLMISSING should mark the
+content as not present in the web if that was the last url. (So should other
+special remotes that remove regular urls, like bittorrent.)
+
+Currently the content is marked as not present in the remote making the change,
+which is the wrong thing! (And SETURLPRESENT/SETURIPRESENT mark content
+as present in the external remote, which also seems unncessary.)
+
+The remaining case is an rmurl on an url with an OtherDownloader,
+which is being removed from some other special remote than web, when there are
+some more urls with OtherDownloader that were set by other special remotes.
+
+I think that it doesn't actually make sense for rmurl of such an url to 
+mark the content as not being present in the special remote. The user should
+drop it if they want to remove it from the special remote. It's ok for it to
+remove the url but not update the presence information.
+"""]]

doc/git-annex-rmurl/comment_2_181581caac6ee439ba1003ebca79ed09._comment

@@ -6,7 +6,6 @@
 rmurl should mark the content as not being present in the web special
 remote once the last url is removed, and it does when I tested it just now.
 
-Please file a bug report if git-annex does not behave as expected.. It's
-hard to keep track of comments to random man pages, and bloating the end of
-this page with comments about a possible bug is just not great.
+There was a recent bug, now fixed, that prevented it doing that in some unusual
+circumstances.
 """]]