Duplication entries check bug in an application created by Application Within Minutes

Any attempt to make duplication entry gives an error described below. No correct duplication check is done.
How to reproduce:

• make any application
• make an entry
• try to make another entry with the same name.
• follow the error code:

Error number 0 in 11: Uncaught exception
Wrapped Exception: null
com.xpn.xwiki.XWikiException: Error number 0 in 11: Uncaught exception
Wrapped Exception: null
at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:252)
at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:116)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:538)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1352)
at com.xpn.xwiki.web.ActionFilter.doFilter(ActionFilter.java:128)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1323)
at org.xwiki.wysiwyg.server.filter.ConversionFilter.doFilter(ConversionFilter.java:144)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1323)
at com.xpn.xwiki.plugin.webdav.XWikiDavFilter.doFilter(XWikiDavFilter.java:68)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1323)
at org.xwiki.container.servlet.filters.internal.SavedRequestRestorerFilter.doFilter(SavedRequestRestorerFilter.java:217)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1323)
at org.xwiki.container.servlet.filters.internal.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:109)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1323)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:476)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:119)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:517)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:225)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:937)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:406)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:183)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:871)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:117)
at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:247)
at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:149)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:110)
at org.eclipse.jetty.server.Server.handle(Server.java:346)
at org.eclipse.jetty.server.HttpConnection.handleRequest(HttpConnection.java:589)
at org.eclipse.jetty.server.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:1048)
at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:601)
at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:214)
at org.eclipse.jetty.server.HttpConnection.handle(HttpConnection.java:411)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:535)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:40)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:529)
at java.lang.Thread.run(Unknown Source)

Wrapped Exception:

java.util.ConcurrentModificationException
at java.util.AbstractList$Itr.checkForComodification(Unknown Source)
at java.util.AbstractList$Itr.next(Unknown Source)
at com.xpn.xwiki.doc.XWikiDocument.setXObjects(XWikiDocument.java:2089)
at com.xpn.xwiki.doc.XWikiDocument.mergeXObjects(XWikiDocument.java:2437)
at com.xpn.xwiki.doc.XWikiDocument.readFromTemplate(XWikiDocument.java:3271)
at com.xpn.xwiki.doc.XWikiDocument.readFromTemplate(XWikiDocument.java:3289)
at com.xpn.xwiki.doc.XWikiDocument.readFromTemplate(XWikiDocument.java:3224)
at com.xpn.xwiki.web.EditAction.render(EditAction.java:117)
at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:229)
at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:116)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:538)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1352)
at com.xpn.xwiki.web.ActionFilter.doFilter(ActionFilter.java:128)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1323)
at org.xwiki.wysiwyg.server.filter.ConversionFilter.doFilter(ConversionFilter.java:144)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1323)
at com.xpn.xwiki.plugin.webdav.XWikiDavFilter.doFilter(XWikiDavFilter.java:68)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1323)
at org.xwiki.container.servlet.filters.internal.SavedRequestRestorerFilter.doFilter(SavedRequestRestorerFilter.java:217)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1323)
at org.xwiki.container.servlet.filters.internal.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:109)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1323)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:476)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:119)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:517)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:225)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:937)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:406)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:183)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:871)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:117)
at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:247)
at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:149)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:110)
at org.eclipse.jetty.server.Server.handle(Server.java:346)
at org.eclipse.jetty.server.HttpConnection.handleRequest(HttpConnection.java:589)
at org.eclipse.jetty.server.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:1048)
at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:601)
at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:214)
at org.eclipse.jetty.server.HttpConnection.handle(HttpConnection.java:411)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:535)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:40)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:529)
at java.lang.Thread.run(Unknown Source)