CPM updated

cpm/src/CPM/PackageCopy.curry

@@ -176,16 +176,20 @@ getLocalPackageSpec dir =
 
 --- Tries to find a package specification in the current directory or one of its
 --- ancestors. Returns `Nothing` if there is not package specifiction.
+--- In order to avoid infinite loops due to cyclic file structures,
+--- the search is limited to 10 ancestor hierarchies.
 searchLocalPackageSpec :: String -> IO (ErrorLogger (Maybe String))
-searchLocalPackageSpec dir = do
+searchLocalPackageSpec = searchLocalSpec 10
+ where
+  searchLocalSpec m dir = do
     existsLocal <- doesFileExist $ dir </> "package.json"
     if existsLocal
       then succeedIO (Just dir)
       else log Debug ("No package.json in " ++ show dir ++ ", trying " ++
                       show (dir </> "..")) |> do
            parentExists <- doesDirectoryExist $ dir </> ".."
-      if parentExists
-        then searchLocalPackageSpec $ dir </> ".."
+           if m>0 && parentExists
+             then searchLocalSpec (m-1) $ dir </> ".."
              else succeedIO Nothing
 
 --- Resolves the dependencies for a package copy and fills the package caches.