add warning on add of annex link

Warn when adding a annex symlink or pointer file that uses a key that is
not known to the repository, to prevent confusion if the user has copied it
from some other repository.

This commit was sponsored by Jake Vosloo on Patreon.

Annex/Ingest.hs

@@ -21,6 +21,7 @@ module Annex.Ingest (
 	CheckGitIgnore(..),
 	gitAddParams,
 	addAnnexedFile,
+	addingExistingLink,
 ) where
 
 import Annex.Common
@@ -387,3 +388,19 @@ addAnnexedFile ci matcher file key mtmp = ifM (addUnlocked matcher mi)
 		_ -> return ()
 	
 	writepointer mode = liftIO $ writePointerFile file key mode
+
+{- Use with actions that add an already existing annex symlink or pointer
+ - file. The warning avoids a confusing situation where the file got copied
+ - from another git-annex repo, probably by accident. -}
+addingExistingLink :: RawFilePath -> Key -> Annex a -> Annex a
+addingExistingLink f k a = do
+	unlessM (isKnownKey k <||> inAnnex k) $ do
+		islink <- isJust <$> isAnnexLink f
+		warning $ unwords
+			[ fromRawFilePath f
+			, "is a git-annex"
+			, if islink then "symlink." else "pointer file."
+			, "Its content is not available in this repository."
+			, "(Maybe " ++ fromRawFilePath f ++ " was copied from another repository?)"
+			]
+	a

CHANGELOG

@@ -3,6 +3,9 @@ git-annex (8.20201104) UNRELEASED; urgency=medium
   * sync --content: Fix a bug where a file that was not preferred content
     could be transferred to a remote. This happened when the file got deleted
     after the sync started running.
+  * Warn when adding a annex symlink or pointer file that uses a key that
+    is not known to the repository, to prevent confusion if the user has
+    copied it from some other repository.
 
  -- Joey Hess <id@joeyh.name>  Mon, 09 Nov 2020 15:15:20 -0400
 

Command/Add.hs

@@ -27,8 +27,6 @@ import Utility.FileMode
 import Utility.OptParse
 import qualified Utility.RawFilePath as R
 
-import System.Log.Logger (debugM)
-
 cmd :: Command
 cmd = notBareRepo $ 
 	withGlobalOptions opts $
@@ -171,16 +169,17 @@ start o si file addunlockedmatcher = do
 		liftIO (catchMaybeIO $ R.getSymbolicLinkStatus file) >>= \case
 			Just s | isSymbolicLink s -> fixuplink key
 			_ -> add
-	fixuplink key = starting "add" (ActionItemWorkTreeFile file) si $ do
-		liftIO $ debugM "add" "adding existing annex symlink to git"
-		liftIO $ removeFile (fromRawFilePath file)
-		addLink (checkGitIgnoreOption o) file key Nothing
-		next $
-			cleanup key =<< inAnnex key
-	fixuppointer key = starting "add" (ActionItemWorkTreeFile file) si $ do
-		liftIO $ debugM "add" "adding pointer file to git"
-		Database.Keys.addAssociatedFile key =<< inRepo (toTopFilePath file)
-		next $ addFile (checkGitIgnoreOption o) file
+	fixuplink key = 
+		starting "add" (ActionItemWorkTreeFile file) si $
+			addingExistingLink file key $ do
+				liftIO $ removeFile (fromRawFilePath file)
+				addLink (checkGitIgnoreOption o) file key Nothing
+				next $ cleanup key =<< inAnnex key
+	fixuppointer key =
+		starting "add" (ActionItemWorkTreeFile file) si $
+			addingExistingLink file key $ do
+				Database.Keys.addAssociatedFile key =<< inRepo (toTopFilePath file)
+				next $ addFile (checkGitIgnoreOption o) file
 
 perform :: AddOptions -> RawFilePath -> AddUnlockedMatcher -> CommandPerform
 perform o file addunlockedmatcher = withOtherTmp $ \tmpdir -> do

Command/Smudge.hs

@@ -98,8 +98,9 @@ clean file = do
   where
 	go b = case parseLinkTargetOrPointerLazy b of
 		Just k -> do
-			getMoveRaceRecovery k file
-			liftIO $ L.hPut stdout b
+			addingExistingLink file k $ do
+				getMoveRaceRecovery k file
+				liftIO $ L.hPut stdout b
 		Nothing -> do
 			let fileref = Git.Ref.fileRef file
 			indexmeta <- catObjectMetaData fileref

doc/bugs/file_not_correctly_added.mdwn

@@ -219,3 +219,5 @@ $ tree -a
 
 ### Have you had any luck using git-annex before? (Sometimes we get tired of reading bug reports all day and a lil' positive end note does wonders)
 It used to work before. It seem to be broken since a system update. I have tried reinstalling `git-annex` as well as all dependencies, bit without any luck.
+
+> Added warning. [[done]] --[[Joey]]