  
      def get_value(self, dictionary):
          # We override the default field access in order to support
          # lists in HTML forms.
          if html.is_html_input(dictionary):
              val = dictionary.getlist(self.field_name, [])
              if len(val) > 0:
 
</s> remove             ret = dictionary.getlist(self.field_name)
            if getattr(self.root, 'partial', False) and not ret:
                ret = empty
            return ret

 </s> add             return dictionary.getlist(self.field_name)
        if self.field_name not in dictionary:
            if getattr(self.root, 'partial', False):
                return empty
  
      def get_value(self, dictionary):
        if self.field_name not in dictionary:
            if getattr(self.root, 'partial', False):
                return empty
          # We override the default field access in order to support
          # lists in HTML forms.
          if html.is_html_input(dictionary):
              val = dictionary.getlist(self.field_name, [])
              if len(val) > 0:
keep add keep keep keep keep keep
 Fixed #2761 - ListField truncation on HTTP PATCH

- Checked ``partial`` state when getting value in appropriate field
  classes; return ``empty`` immediately if key not submitted. 
rest_framework/fields.py