JIRA 7.9.0 ignore minimum downgrade version

Summary

JIRA 7.9 ignore the minimum downgrade version shown from the entities.xml file.

grep jira.downgrade.minimum.version entities.xml
     jira.downgrade.minimum.version                : 7.1.2

grep '<OSPropertyString id="14"' entities.xml
    <OSPropertyString id="14" value="7.1.2"/>

Environment

• JIRA 7.9.0 and Postgres database

Steps to Reproduce

1. Install a new JIRA 7.9.0 instance and export an XML backup out
2. Install a new JIRA 7.1.2 instance and import 7.9.0 XML backup
3. Failed with the error message:

   2018-04-27 18:59:16,929 JiraImportTaskExecutionThread-1 INFO admin 1139x181x1 1olypsh 10.60.2.117 /secure/admin/XmlRestore.jspa [c.a.j.bc.dataimport.OfbizImportHandler] Failed to parse value for element UpgradeTaskHistoryAuditLog.
   java.lang.IllegalArgumentException: [GenericDelegator.makeValue] could not find entity for entityName: UpgradeTaskHistoryAuditLog
   ..
   org.ofbiz.core.entity.GenericModelException: Could not find definition for entity name UpgradeTaskHistory
   

or stopped at 20% with the following message in the UI:

and without any error message in logs:

2018-04-25 12:52:09,871 JiraImportTaskExecutionThread-1 INFO d.munjiza 771x3298x1 rv21qs 10.1.112.12 /secure/admin/XmlRestore.jspa [c.a.j.bc.dataimport.DefaultDataImportService] Importing data is 20% complete...

Expected Results

It should to be able to downgrade as per entry from entities.xml file

Actual Results

Failed with errors above.

Workaround

No workaround at the moment.

Notes

This bug doesn't appear when when importing XML backup with lower version (tested with 7.2.6)