Language Selector portlet redirection is not working as expected when using virtual hosts

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.0.X, Master
• Fix Version/s: 6.2.X EE, 7.0.0 DXP FP36, 7.0.0 DXP SP7, 7.0.5 CE GA6, 7.0.X, 7.1.0 M1, 7.1.X, Master
• Component/s: Portal Services > Localization, WCM > Languages Portlet
• Labels:
  • ee-ts
  • liferay-digital-enterprise-70-sp7
  • liferay-fixpack-de-36-7010
  • liferay-fixpack-portal-168-6210
• Branch Version/s:
  7.0.x, 6.2.x
• Backported to Branch:
  Committed
• Story Points: 1
• Fix Priority: 3
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/53733

The Language Selection portlet does not redirect properly when using a virtual host for private pages. This specifically occurs when a Language Selection portlet is being used on a public page and the user is navigating this public page via the virtual host.

Steps to Reproduce

1. Startup DXP
2. Create a new public page for default site with name "Login" and friendly url "/login".
3. Create a new private page with an arbitrary name.
4. Set virtual host for private pages of that site to an arbitrary hostname (From now on let's assume it is "test.dev").
5. Put the language portlet onto the just created page "Login".
6. Open "test.dev:8080". You should automatically get redirected to the login page.
7. Use the language portlet to change the language.

Expected behavior:
The page is shown with the selected language.

Actual behavior:
You get redirected to an error page showing that the current page is not available.