[WICKET-6116] Exception 'A child already exists' when backing to a page with some markups in a Border

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 7.2.0
• Fix Version/s: 7.3.0, 8.0.0-M1
• Component/s: wicket
• Environment: MacBook Pro, OS X 10.11.3
• Assignee: Andrea Del Bene
• Reporter: GLEDSON BEZERRA DE OLIVEIRA RABELO
• Created: 10/Mar/16 20:03
• Updated: 19/Mar/16 16:04
• Resolved: 19/Mar/16 16:04

Description

The problem is easy to simulate and I am sending an example.
It occurs when you have a page with border containing an img tag.
Just leave the page and press the back button and the exception is thrown.

java.lang.IllegalArgumentException: A child 'TransparentWebMarkupContainer' with id 'wicket_relative_path_prefix_1' already exists:
[BorderBodyContainer [Component id = myborder_body]]
at org.apache.wicket.MarkupContainer.add(MarkupContainer.java:234)
at org.apache.wicket.markup.html.border.Border.add(Border.java:227)
at org.apache.wicket.markup.html.border.Border.add(Border.java:140)
at org.apache.wicket.MarkupContainer.autoAdd(MarkupContainer.java:312)
at org.apache.wicket.MarkupContainer.renderNext(MarkupContainer.java:1513)
at org.apache.wicket.MarkupContainer.renderAll(MarkupContainer.java:1759)
at org.apache.wicket.MarkupContainer.renderComponentTagBody(MarkupContainer.java:1734)
at org.apache.wicket.MarkupContainer.renderAssociatedMarkup(MarkupContainer.java:797)
at org.apache.wicket.markup.html.panel.AssociatedMarkupSourcingStrategy.renderAssociatedMarkup(AssociatedMarkupSourcingStrategy.java:77)
at org.apache.wicket.markup.html.panel.BorderMarkupSourcingStrategy.onComponentTagBody(BorderMarkupSourcingStrategy.java:46)
at org.apache.wicket.Component.internalRenderComponent(Component.java:2565)
at org.apache.wicket.MarkupContainer.onRender(MarkupContainer.java:1698)
at org.apache.wicket.Component.internalRender(Component.java:2380)
at org.apache.wicket.Component.render(Component.java:2308)
at org.apache.wicket.MarkupContainer.renderNext(MarkupContainer.java:1524)
at org.apache.wicket.MarkupContainer.renderAll(MarkupContainer.java:1759)
at org.apache.wicket.Page.onRender(Page.java:879)
at org.apache.wicket.markup.html.WebPage.onRender(WebPage.java:141)
at org.apache.wicket.Component.internalRender(Component.java:2380)
at org.apache.wicket.Component.render(Component.java:2308)
at org.apache.wicket.Page.renderPage(Page.java:1018)
at org.apache.wicket.request.handler.render.WebPageRenderer.renderPage(WebPageRenderer.java:124)
at org.apache.wicket.request.handler.render.WebPageRenderer.respond(WebPageRenderer.java:195)
at org.apache.wicket.core.request.handler.RenderPageRequestHandler.respond(RenderPageRequestHandler.java:175)
at org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:895)
at org.apache.wicket.request.RequestHandlerStack.execute(RequestHandlerStack.java:64)
at org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:265)
at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:222)
at org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:293)
at org.apache.wicket.protocol.http.WicketFilter.processRequestCycle(WicketFilter.java:261)
at org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:203)
at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:284)