LP #950689: Fix HTTPS detection under mod_wsgi.

doc/CHANGES.rst

@@ -8,6 +8,8 @@ http://docs.zope.org/zope2/releases/.
 2.13.14 (unreleased)
 --------------------
 
+- LP #950689: Fix HTTPS detection under mod_wsgi.
+
 - LP #975039: Don't translate interface names in edit_markers ZMI view.
 
 - LP #838978: Fixed TypeError in cache_detail ZMI view.

src/ZPublisher/HTTPRequest.py

@@ -383,8 +383,8 @@ class HTTPRequest(BaseRequest):
         if server_url is not None:
             other['SERVER_URL'] = server_url = server_url.strip()
         else:
-            if 'HTTPS' in environ and (
-                environ['HTTPS'] == "on" or environ['HTTPS'] == "ON"):
+            https_environ = environ.get('HTTPS', False)
+            if https_environ and https_environ in ('on', 'ON', '1'):
                 protocol = 'https'
             elif ('SERVER_PORT_SECURE' in environ and
                 environ['SERVER_PORT_SECURE'] == "1"):