fix: cae1bbf2536b - expression errors not setting result properly

Rather than setting 'result' in renderContext, I was wrirting the
output directly, but was stil falling through to where result would be
used.

This caused email to be sent to the admin and when test_mailgw was
called the mail-test.log was somehow created and caused the test there
to fail.

Fixed renderContext to use result variable and output contents of
mail-test.log to make debugging easier.

This should fix CI failure.

Author: rouilj

roundup/cgi/client.py

@@ -2233,7 +2233,7 @@ def renderContext(self):
             except ExpressionError as e:
                 self.add_error_message(str(e))
                 self.template = "search"
-                self.write_html(self.renderContext())
+                result = self.renderContext()
 
             if 'Content-Type' not in self.additional_headers:
                 self.additional_headers['Content-Type'] = pt.content_type

test/test_mailgw.py

@@ -539,6 +539,9 @@ def testAlternateAddress(self):
 This is a test submission of a new issue.
 ''')
         userlist = self.db.user.list()
+        if os.path.exists(SENDMAILDEBUG):
+            with open(SENDMAILDEBUG) as f:
+                print(f.read())
         assert not os.path.exists(SENDMAILDEBUG)
         self.assertEqual(userlist, self.db.user.list(),
             "user created when it shouldn't have been")