allow configuration settings to specify a session cookie name. This is to...

allow configuration settings to specify a session cookie name. This is to avoid problems we are experiencing between simultaneous login sessions between edx.org and edge.edx.org on certain browsers (i.e. Firefox)

cms/envs/aws.py

@@ -91,6 +91,12 @@ CACHES = ENV_TOKENS['CACHES']
 
 SESSION_COOKIE_DOMAIN = ENV_TOKENS.get('SESSION_COOKIE_DOMAIN')
 
+# allow for environments to specify what cookie name our login subsystem should use
+# this is to fix a bug regarding simultaneous loging between edx.org and edge.edx.org which can
+# happen with some browsers (e.g. Firefox)
+if ENV_TOKENS.get('SESSION_COOKIE_NAME', None):
+    SESSION_COOKIE_NAME = ENV_TOKENS.get('SESSION_COOKIE_NAME')
+
 #Email overrides
 DEFAULT_FROM_EMAIL = ENV_TOKENS.get('DEFAULT_FROM_EMAIL', DEFAULT_FROM_EMAIL)
 DEFAULT_FEEDBACK_EMAIL = ENV_TOKENS.get('DEFAULT_FEEDBACK_EMAIL', DEFAULT_FEEDBACK_EMAIL)