OOME when web content display widget's configuration is opened

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.2.X, 7.3.X, Master
• Fix Version/s: 7.2.10 DXP FP13, 7.2.X, 7.3.7 CE GA8, 7.3.10 DXP FP2, 7.3.X, 7.4.0 CE GA1, 7.4.13 DXP GA1, Master
• Component/s: Content Display Widgets > Web Content Display widget
• Labels:
  • ee-ts
  • liferay-fixpack-dxp-13-7210
  • liferay-fixpack-dxp-2-7310
• Branch Version/s:
  7.3.x, 7.2.x
• Backported to Branch:
  Committed
• Fix Priority: 4
• Git Pull Request: https://github.com/liferay-echo/liferay-portal/pull/4151

Reproductions steps:

1. Create a new Web Content Structure with any type of field
2. Add a Web Content Template to it with the following snippet:
   <@liferay_portlet["runtime"]
   portletName="com_liferay_journal_content_web_portlet_JournalContentPortlet"
   instanceId="randomString"
   />
3. Create a Web Content based on the new structure
4. Place the Web Content on a page
5. Open the (outer) Web Content Display's configuration
6. Check Related Assets under Content Metadata
7. Save the configuration

Expected behaviour: Save is successful
Actual behaviour: Saving processes endlessly until an OutOfMemoryError is displayed in the logs