code: def search_image(name=None, path=['.']):
      
      name = strutils.decode(name)
      for image_dir in path:
          if not os.path.isdir(image_dir):
              continue
          image_dir = strutils.decode(image_dir)
          image_path = os.path.join(image_dir, name)
          if os.path.isfile(image_path):
              return strutils.encode(image_path)
  
          for image_path in list_all_image(image_dir):
              if not image_name_match(name, image_path):
                  continue
              return strutils.encode(image_path)
      return None
docs: look for the image real path, if name is None, then return all images under path.
  
      @return system encoded path string
      FIXME(ssx): this code is just looking wired.