Reindexing com.liferay.portal.kernel.model.Layout does not properly reindex all layouts

• Type: Regression Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.1.X
• Fix Version/s: 7.1.10 DXP FP20, 7.1.10.5 SP5, 7.1.X
• Component/s: Fragment Administration
• Labels:
  • ee-ts
  • liferay-dxp-71-sp5
  • liferay-fixpack-dxp-20-7110
• Branch Version/s:
  7.1.x
• Fix Priority: 3
• Last Working Version:
  7.1.10 DXP FP16
• Git Pull Request: https://github.com/dacousalr/liferay-portal-ee/pull/179

Steps to Reproduce

1. Start Liferay 71x (FP17 or higher)
2. Navigate to Control Panel -> Configuration -> Server Administration -> Log Level
   • Add Category
     • Logger Name: com.liferay.portal.search.internal.IndexWriterHelperImpl
     • Log Level : DEBUG
3. Create a Widget page
   • Notice the logs show an entry being added to the index:

     2020-09-16 05:12:03.494 DEBUG [http-nio-8080-exec-10][IndexWriterHelperImpl:570] Document{entryClassPK=[35129], entryClassName=[com.liferay.portal.kernel.model.Layout], groupId=[20127], defaultLanguageId=[en_US], createDate_sortable=[1600233123435], userName=[test test], privateLayout=[false], type=[portlet], userId=[20140], stagingGroup=[false], uid=[com.liferay.portal.kernel.model.Layout_PORTLET_35129], companyId=[20099], assetCategoryIds=[], scopeGroupId=[20127], name=null, modified=[20200916051203], modified_sortable=[1600233123435], title_en_US=[Widget Page 1], createDate=[20200916051203]} 

4. Navigate to Control Panel -> Configuration -> Search
5. Execute Reindex for: com.liferay.portal.kernel.model.Layout

Expected Result
During the reindex, an entry is created for the widget page

Actual Result
No entry is created for the widget page

Note: A lot of entries are actually missing, if we follow the same steps using FP16 and compare the results