Adjust docstring

CHANGES.rst

@@ -13,7 +13,8 @@ https://github.com/zopefoundation/Zope/blob/4.x/CHANGES.rst
 
 - Update to newest compatible versions of dependencies.
 
-- Use string representation of response data that has no ``__bytes__``
+- Use intermediate ``str`` representation for complex response data (i.e. not
+  ``str`` or ``bytes`` like)
   (`#1006 <https://github.com/zopefoundation/Zope/issues/1006>`_)
 
 

src/ZPublisher/HTTPResponse.py

@@ -498,11 +498,13 @@ def setBody(self, body, title='', is_error=False, lock=None):
         If the body is a 2-element tuple, then it will be treated
         as (title,body)
 
-        If body is unicode, encode it.
+        If body has an 'asHTML' method, replace it by the result of that
+        method.
 
-        If body is not a string or unicode, but has an 'asHTML' method, use
-        the result of that method as the body;  otherwise, use the 'str'
-        of body.
+        If body is unicode, encode it. If it is more complex (no str or bytes
+        and no '__bytes__' method), use its 'str' representation and encode the
+        result. Else, convert it to bytes, falling back to the encoded 'str'
+        representation if this yields an error.
 
         If is_error is true, format the HTML as a Zope error message instead
         of a generic HTML page.