Simplifications:

- Handle the base "newcert" cases at the top, rather than with a very long if
   statement
 - Avoid having a state-tracking "question variable"

letsencrypt/cli.py

@@ -240,12 +240,14 @@ def _treat_as_renewal(config, domains):
     # related to an existing certificate.  (config.duplicate, which
     # is set with --duplicate, skips all of this logic and forces any
     # kind of certificate to be obtained with renewal = False.)
-    if not config.duplicate:
-        ident_names_cert, subset_names_cert = _find_duplicative_certs(
-            config, domains)
+    if config.duplicate:
+        return "newcert", None
+    ident_names_cert, subset_names_cert = _find_duplicative_certs(config, domains)
     # I am not sure whether that correctly reads the systemwide
     # configuration file.
-        question = None
+    if not (ident_names_cert or subset_names_cert):
+        return "newcert", None
+
     if ident_names_cert is not None:
         return _handle_identical_cert_request(ident_names_cert)
     elif subset_names_cert is not None:
@@ -259,11 +261,7 @@ def _treat_as_renewal(config, domains):
                  ", ".join(subset_names_cert.names()),
                  ", ".join(domains),
                  br=os.linesep)
-        if question is None:
-            # We aren't in a duplicative-names situation at all, so we don't
-            # have to tell or ask the user anything about this.
-            pass
-        elif config.renew_by_default or zope.component.getUtility(
+        if config.renew_by_default or zope.component.getUtility(
                 interfaces.IDisplay).yesno(question, "Replace", "Cancel"):
             return "renew", subset_names_cert
         else:
@@ -282,8 +280,6 @@ def _treat_as_renewal(config, domains):
                 "User did not use proper CLI and would like "
                 "to reinvoke the client.")
 
-    return "newcert", None
-
 def _handle_identical_cert_request(cert):
     """Figure out what to do if a cert has the same names as a perviously obtained one