remove absNormPathUnix again

Moving toward dropping MissingH dep.

I think I've addressed the problem identified earlier in
09a66f702d. On Windows,
absPathFrom "/tmp/repo/xxx" "y/bar" would be "/tmp/repo/xxx\\y/bar",
which then confuses relPathDirToFile. Fixed by converting to unix (git)
style paths.

Also, relPathDirToFile was splitting only on \\ on windows and not /
which broke the example in 09a66f702d of
relPathDirToFile (absPathFrom "/tmp/repo/xxx" "y/bar") "/tmp/repo/.git/annex/objects/xxx"

Now, on windows, that will yield "..\\..\\..\\.git/annex/objects/xxx"
which once converted to unix style paths is what we want.

Annex/Locations.hs

@@ -172,7 +172,7 @@ gitAnnexLocation' key r config crippled symlinkssupported checker gitdir
 gitAnnexLink :: FilePath -> Key -> Git.Repo -> GitConfig -> IO FilePath
 gitAnnexLink file key r config = do
 	currdir <- getCurrentDirectory
-	let absfile = fromMaybe whoops $ absNormPathUnix currdir file
+	let absfile = absNormPathUnix currdir file
 	let gitdir = getgitdir currdir
 	loc <- gitAnnexLocation' key r config False False (\_ -> return True) gitdir
 	toInternalGitPath <$> relPathDirToFile (parentDir absfile) loc
@@ -182,10 +182,10 @@ gitAnnexLink file key r config = do
 		 - supporting symlinks; generate link target that will
 		 - work portably. -}
 		| not (coreSymlinks config) && needsSubmoduleFixup r =
-			fromMaybe whoops $ absNormPathUnix currdir $
+			absNormPathUnix currdir $ Git.repoPath r </> ".git"
-				Git.repoPath r </> ".git"
 		| otherwise = Git.localGitDir r
-	whoops = error $ "unable to normalize " ++ file
+	absNormPathUnix d p = toInternalGitPath $
+		absPathFrom (toInternalGitPath d) (toInternalGitPath p)
 
 {- Calculates a symlink target as would be used in a typical git
  - repository, with .git in the top of the work tree. -}

Utility/Path.hs

@@ -25,7 +25,6 @@ import System.Posix.Files
 import Utility.Exception
 #endif
 
-import qualified "MissingH" System.Path as MissingH
 import Utility.Monad
 import Utility.UserInfo
 import Utility.Directory
@@ -68,18 +67,6 @@ simplifyPath path = dropTrailingPathSeparator $
 absPathFrom :: FilePath -> FilePath -> FilePath
 absPathFrom dir path = simplifyPath (combine dir path)
 
-{- On Windows, this converts the paths to unix-style, in order to run
- - MissingH's absNormPath on them. -}
-absNormPathUnix :: FilePath -> FilePath -> Maybe FilePath
-#ifndef mingw32_HOST_OS
-absNormPathUnix dir path = MissingH.absNormPath dir path
-#else
-absNormPathUnix dir path = todos <$> MissingH.absNormPath (fromdos dir) (fromdos path)
-  where
-	fromdos = replace "\\" "/"
-	todos = replace "/" "\\"
-#endif
-
 {- takeDirectory "foo/bar/" is "foo/bar". This instead yields "foo" -}
 parentDir :: FilePath -> FilePath
 parentDir = takeDirectory . dropTrailingPathSeparator
@@ -149,13 +136,13 @@ relPathDirToFile from to = relPathDirToFileAbs <$> absPath from <*> absPath to
 relPathDirToFileAbs :: FilePath -> FilePath -> FilePath
 relPathDirToFileAbs from to
 	| takeDrive from /= takeDrive to = to
-	| otherwise = intercalate s $ dotdots ++ uncommon
+	| otherwise = joinPath $ dotdots ++ uncommon
   where
-	s = [pathSeparator]
+	pfrom = sp from
-	pfrom = split s from
+	pto = sp to
-	pto = split s to
+	sp = dropTrailingPathSeparator . splitPath
 	common = map fst $ takeWhile same $ zip pfrom pto
-	same (c,d) = c == d
+	same (c,d) = c = d
 	uncommon = drop numcommon pto
 	dotdots = replicate (length pfrom - numcommon) ".."
 	numcommon = length common