Log received data AFTER filtering.

This allows applications to filter out sensitive information, such
as passwords, so that it won't appear in the logs.

It does mean that the debug logs will not show the actual received
data, and there will be no indication of tampering, unless the
filter author explicitly logs and notes that a change was made.

sleekxmpp/xmlstream/xmlstream.py

@@ -1276,8 +1276,6 @@ class XMLStream(object):
         :param xml: The :class:`~sleekxmpp.xmlstream.stanzabase.ElementBase`
                     stanza to analyze.
         """
-        log.debug("RECV: %s", tostring(xml, xmlns=self.default_ns,
-                                            stream=self))
         # Apply any preprocessing filters.
         xml = self.incoming_filter(xml)
 
@@ -1291,6 +1289,9 @@ class XMLStream(object):
         if stanza is None:
             return
 
+        log.debug("RECV: %s", tostring(xml, xmlns=self.default_ns,
+                                            stream=self))
+
         # Match the stanza against registered handlers. Handlers marked
         # to run "in stream" will be executed immediately; the rest will
         # be queued.