deal with .git pointer file in Git.CurrentRepo

This fixes the bug.

Note, it's only done when GIT_DIR is set. When it's not set,
Git.Construct already handled it. This is why it was only noticed with this
git submodule command.

This commit was sponsored by Brett Eisenberg on Patreon.

CHANGELOG

@@ -12,6 +12,8 @@ git-annex (8.20201008) UNRELEASED; urgency=medium
   * When a special remote has chunking enabled, but no chunk sizes are
     recorded (or the recorded ones are not found), speculatively try
     chunks using the configured chunk size.
+  * Fixed some problems that prevented this command from working:
+    git submodule foreach git annex init
 
  -- Joey Hess <id@joeyh.name>  Thu, 08 Oct 2020 10:48:17 -0400
 

Git/Construct.hs

@@ -21,6 +21,7 @@ module Git.Construct (
 	repoAbsPath,
 	checkForRepo,
 	newFrom,
+	adjustGitDirFile,
 ) where
 
 #ifndef mingw32_HOST_OS
@@ -73,7 +74,7 @@ fromAbsPath dir
 				, ret (takeDirectory canondir)
 				)
 		| otherwise = ifM (doesDirectoryExist dir)
-			( gitDirFile dir >>= maybe (ret dir) (pure . newFrom)
+			( checkGitDirFile dir >>= maybe (ret dir) (pure . newFrom)
 			-- git falls back to dir.git when dir doesn't
 			-- exist, as long as dir didn't end with a
 			-- path separator
@@ -198,7 +199,7 @@ expandTilde = expandt True
 checkForRepo :: FilePath -> IO (Maybe RepoLocation)
 checkForRepo dir = 
 	check isRepo $
-		check (gitDirFile dir) $
+		check (checkGitDirFile dir) $
 			check isBareRepo $
 				return Nothing
   where
@@ -219,24 +220,36 @@ checkForRepo dir =
 		<&&> doesDirectoryExist (dir </> "objects")
 	gitSignature file = doesFileExist $ dir </> file
 
+-- Check for a .git file.
+checkGitDirFile :: FilePath -> IO (Maybe RepoLocation)
+checkGitDirFile dir = adjustGitDirFile' $ Local 
+	{ gitdir = toRawFilePath (dir </> ".git")
+	, worktree = Just (toRawFilePath dir)
+	}
+
 -- git-submodule, git-worktree, and --separate-git-dir
 -- make .git be a file pointing to the real git directory.
 -- Detect that, and return a RepoLocation with gitdir pointing 
 -- to the real git directory.
-gitDirFile :: FilePath -> IO (Maybe RepoLocation)
-gitDirFile dir = do
-	c <- firstLine <$>
-		catchDefaultIO "" (readFile $ dir </> ".git")
-	return $ if gitdirprefix `isPrefixOf` c
-		then Just $ Local 
-			{ gitdir = toRawFilePath $ absPathFrom dir $
-				drop (length gitdirprefix) c
-			, worktree = Just (toRawFilePath dir)
-			}
-		else Nothing
+adjustGitDirFile :: RepoLocation -> IO RepoLocation
+adjustGitDirFile loc = fromMaybe loc <$> adjustGitDirFile' loc
+
+adjustGitDirFile' :: RepoLocation -> IO (Maybe RepoLocation)
+adjustGitDirFile' loc = do
+	let gd = fromRawFilePath (gitdir loc)
+	c <- firstLine <$> catchDefaultIO "" (readFile gd)
+	if gitdirprefix `isPrefixOf` c
+		then do
+			top <- takeDirectory <$> absPath gd
+			return $ Just $ loc
+				{ gitdir = toRawFilePath $ absPathFrom top $
+					drop (length gitdirprefix) c
+				}
+		else return Nothing
  where
 	gitdirprefix = "gitdir: "
 
+
 newFrom :: RepoLocation -> Repo
 newFrom l = Repo
 	{ location = l

Git/CurrentRepo.hs

@@ -67,15 +67,14 @@ get = do
 	configure (Just d) _ = do
 		absd <- absPath d
 		curr <- getCurrentDirectory
-		r <- Git.Config.read $ newFrom $
-			Local
-				{ gitdir = toRawFilePath absd
-				, worktree = Just (toRawFilePath curr)
-				}
+		loc <- adjustGitDirFile $ Local
+			{ gitdir = toRawFilePath absd
+			, worktree = Just (toRawFilePath curr)
+			}
+		r <- Git.Config.read $ newFrom loc
 		return $ if Git.Config.isBare r
 			then r { location = (location r) { worktree = Nothing } }
 			else r
-
 	configure Nothing Nothing = giveup "Not in a git repository."
 
 	addworktree w r = changelocation r $ Local

doc/bugs/__34__git_submodule_foreach_git_annex_init__34___fails_with___34__git__58___createProcess__58___runInteractiveProcess__58___chdir__58___inappropriate_type___40__Not_a_directory__41____34__.mdwn

@@ -28,3 +28,5 @@ As a workaround, manually changing directory into each submodule and running `gi
 ### 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)
 
 I use it regularly with great success :)
+
+> [[fixed|done]] --[[Joey]]

doc/bugs/__34__git_submodule_foreach_git_annex_init__34___fails_with___34__git__58___createProcess__58___runInteractiveProcess__58___chdir__58___inappropriate_type___40__Not_a_directory__41____34__/comment_3_23f3dac4a22cf7202a0bb849ee499766._comment

@@ -25,13 +25,11 @@ Where does that path that does not exist come from?
 .git/modules/sub/config has "core.worktree = ../../../sub"
 
 git clone sets that. And it's a path from ../.git/modules/sub/
-back to the work tree. git-annex interprets it as well, a regular path
-from the cwd, like it usually is. It's worth noting that setting
-`GIT_WORK_TREE` to the same value makes git behave differently!
-Nothing in git's docs seem to explain this mess.
+back to the work tree. git-annex interprets it as relative to `GIT_DIR`,
+which git submodule sets to ".git".
 
 So git-annex needs to check if .git is a gitdir: reference, and
-then interpret core.worktree relative to it.
+then interpret core.worktree relative to what it points to.
 
 Or, alternatively, fixupUnusualRepos could learn to tell if the *current*
 command is git-annex init, and go ahead with the fixes. Which would avoid