BPR-4844 's outcome, StagingImpl is using 2 different ways to save layoutBranchId to the DB.
Start a vanilla 6.2 with fresh DB.
Create a new site with 30 pages.
Start Staging on the site with page versioning enabled.
Select 6 pages and publish a new version of them.
Select 2 of those pages and publish a yet again.
Checkpoint: In the DB, portalpreferences table will have multiple xml name-value pairs belonging to com.liferay.portal.kernel.staging.Staging for the current user.
Stop the Portal and Patch it with sp20.
Run the PortalPreferences's verify process
Verify that the DB only has one staging related xml entry with name: com.liferay.portal.kernel.staging.Staging#stagingRecentLayoutIdsMap, value is not empty.
Start the Portal
Publish 2 random pages.
Check the portalpreferences table.
Expected: Portal Preferences only has the JSON object.
Actual: Portal Preferences has both normal xml entries and the JSON object.