Validate local collection symlink targets

Author: OskarEichler

lib/rbs/collection/config/lockfile.rb

@@ -82,7 +82,9 @@ def check_rbs_availability!
               raise CollectionNotAvailable unless meta_path.exist?
               raise CollectionNotAvailable unless library_data(gem) == YAML.load(meta_path.read)
             when Sources::Local
-              raise CollectionNotAvailable unless fullpath.join(gem[:name], gem[:version]).symlink?
+              installed_path = fullpath.join(gem[:name], gem[:version])
+              source_path = source.full_path.join(gem[:name], gem[:version])
+              raise CollectionNotAvailable unless installed_path.symlink? && File.identical?(installed_path, source_path)
             end
           end
         end