Why does Liferay inject redirectUrl to /web/guest/home in my website?

Issue

• Opening the HTML source of the home page in a website made with Liferay DXP, customers may notice the following script injected:
  

  Liferay.Session = new Liferay.SessionBase({
   autoExtend: !0,
   redirectOnExpire: !0,
   redirectUrl: "https://www.myproductionwebsite.com/web/guest/home",
   sessionLength: 900,
   warningLength: 0
  });

This may be wrong as, in most of the cases, in a real-life scenario, the path /web/guest/home does not exist and, as an effect, DXP users will be brought to a non-existing page upon session expiration.

Environment

• Liferay DXP 7.0+

Resolution

• You may leverage the /web/guest/home part from the portal's interface: left Product Menu > Control Panel > Configuration > Instance Settings > Configuration > Navigation > Home URL where the tooltip states:

  "This is the home page of the Liferay instance. For example, if you want the home page to be http://localhost:8080/web/guest/home, set this to /web/guest/home."

Additional Information

• The tag is injected by this code: https://github.com/liferay/liferay-portal/blob/7.0.x/portal-web/docroot/html/common/themes/session_timeout.jspf#L34
  

  redirectOnExpire: <%= SSOUtil.isSessionRedirectOnExpire(themeDisplay.getCompanyId()) %>