Save Tier Price Entries two time give an error

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: Centaurus
• Fix Version/s: None
• Component/s: Digital Merchandise Management → Price Lists
• Labels: None
• Git Pull Request: https://github.com/marco-leo/liferay-portal-ee/pull/1001
• Application Servers:
  Apache Tomcat 9.0.x
• Browsers:
  Chrome (latest)
• Databases:
  MySQL 5.7
• Device Type:
  Desktop
• Search:
  Elasticsearch 6.x
• Portal Version/s:
  7.1.x
• Sprint: FlexSprint9

Steps to Reproduce

• Go to Control Panel → Commerce → Price List.
• Click the  button.
• Create a new price list.
• Click the "Publish" button.
• Go into the Entries tab.
• Click the  button.
• Add one product eg. Bearings.
• Click the "Add" button.
• Edit the new entry in this case Bearings.
• Go into Tier Price Entries.
• Click the  button.
• Click on the "Save" button.
• Edit the new Tier Price Entry.
• Click on the "Save" button.
• Retry to edit again.

Expected Result

 Everything works.

Actual Result

 You can't open the entry.

With this log error:

ERROR [http-nio-8080-exec-2][render_portlet_jsp:131] nullERROR [http-nio-8080-exec-2][render_portlet_jsp:131] nulljava.lang.NullPointerException at com.liferay.commerce.currency.model.impl.CommerceCurrencyImpl.round(CommerceCurrencyImpl.java:39) at org.apache.jsp.edit_005ftier_005fprice_005fentry_jsp._jspService(edit_005ftier_005fprice_005fentry_jsp.java:529) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:111) at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:411) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:473) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:377) at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) at com.liferay.portal.osgi.web.servlet.jsp.compiler.internal.JspServlet.service(JspServlet.java:369) at com.liferay.portal.osgi.web.servlet.jsp.compiler.internal.JspServlet.service(JspServlet.java:380) at org.eclipse.equinox.http.servlet.internal.registration.EndpointRegistration.service(EndpointRegistration.java:153) at org.eclipse.equinox.http.servlet.internal.servlet.ResponseStateHandler.processRequest(ResponseStateHandler.java:62) at org.eclipse.equinox.http.servlet.internal.context.DispatchTargets.doDispatch(DispatchTargets.java:120) at org.eclipse.equinox.http.servlet.internal.servlet.RequestDispatcherAdaptor.include(RequestDispatcherAdaptor.java:48) at com.liferay.portlet.internal.PortletRequestDispatcherImpl.dispatch(PortletRequestDispatcherImpl.java:319) at com.liferay.portlet.internal.PortletRequestDispatcherImpl.include(PortletRequestDispatcherImpl.java:128) at com.liferay.portal.kernel.portlet.bridges.mvc.MVCPortlet.include(MVCPortlet.java:592) at com.liferay.portal.kernel.portlet.bridges.mvc.MVCPortlet.include(MVCPortlet.java:608) at com.liferay.portal.kernel.portlet.bridges.mvc.MVCPortlet.doDispatch(MVCPortlet.java:489) at javax.portlet.GenericPortlet.render(GenericPortlet.java:291)