fix broken 'import_file' when using t/ or test/ directory

bin/cmdtest.rb

@@ -282,8 +282,8 @@ module Cmdtest
       @orig_env_path.dup
     end
 
-    def test_files_dir
-      @project_dir.test_files_dir
+    def test_files_top
+      @project_dir.test_files_top
     end
 
     def run(clog)
@@ -341,6 +341,10 @@ module Cmdtest
       File.expand_path(File.dirname(test_filenames[0]), ORIG_CWD)
     end
 
+    def test_files_top
+      ORIG_CWD
+    end
+
     private
 
     def _fs_test_filenames

lib/cmdtest/testcase.rb

@@ -103,7 +103,7 @@ module Cmdtest
     # the current directory at the time of the call.
 
     def import_file(src, tgt)
-      src_path = File.expand_path(src, @_runner.test_files_dir)
+      src_path = File.expand_path(src, @_runner.test_files_top)
       tgt_path = _cwd_path(tgt)
       FileUtils.mkdir_p(File.dirname(tgt_path))
       FileUtils.cp(src_path, tgt_path)