[MYFACES-1708] duplicate id exception with JSTL conditional tag

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Affects Version/s: 1.1.5
• Component/s: General
• Environment: JDK 1.5.0_12-b04/Linux amd64 or JDK 1.5.0_07-87/MacOS X, Tomcat 5.5.17
• Assignee: Unassigned
• Reporter: Kenji Nagahashi
• Created: 15/Aug/07 21:06
• Updated: 28/Aug/15 16:35
• Resolved: 28/Aug/15 16:35

Description

It might have been better to reopen MYFACES-603, but observed behavior is slightly different.

I'm using JSTL's <c:if> to dynamically change view component tree depending on application state. This consistently results in duplicate id exception in JspStateManagerImpl.checkForDuplicateIds(). I have been thinking it's a bad thing to do, but I may have found a problem in MyFaces.

UIComponentTag.removeFormerChildren method removes former children not seen during rendering. It uses UIComponent.findComponent() for looking up children, but the method returns a child of other UIComponent under certain situations - specifically when two UIComponents have the same id due to changed automatically-assigned IDs. So former UIComponent incorrectly remains in the view tree, causing duplicate id exception.