Submitting a form withing a Display Page redirects to a blank page

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.2.X, Master
• Fix Version/s: 7.2.10 DXP FP5, 7.2.10.2 DXP SP2, 7.2.X, 7.3.1 CE GA2, 7.3.2 CE GA3, 7.3.10 DXP GA1, Master
• Component/s: Page Templates > Display Page Templates
• Labels:
  • ee-ts
  • liferay-dxp-72-sp2
  • liferay-fixpack-dxp-5-7210
  • pt-app-security-review
• Branch Version/s:
  7.2.x
• Backported to Branch:
  Committed
• Fix Priority: 3
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/86012

Steps to reproduce:

1. Add a new simple form.
2. Add a new display page template "dpt": include the form widget on it and select the recently created form to display.
3. Add a new web content, "wc": set as its display page template the one created in 2.
4. Go to http://localhost:8080/web/guest/w/wc
5. Fill and submit the form of "dpt".

Expected result: after submitting the form, it redirects you to the same page in /web/guest/w/wc

Current result: after submitting the form, you are redirected to the display template page, which now looks empty, redirecting to /web/guest/dpt