[TAP5-636] Using Element.forceAttribute() with a null value can cause a later NPE during rendering under some circumstances

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 5.1.0.3
• Fix Version/s: 5.1.0.3
• Component/s: tapestry-core
• Assignee: Howard Lewis Ship
• Reporter: Howard Lewis Ship
• Created: 08/Apr/09 16:41
• Updated: 08/Apr/09 18:02
• Resolved: 08/Apr/09 18:02

Description

An unexpected application exception has occurred.

• java.lang.NullPointerException
• org.apache.tapestry5.dom.AbstractMarkupModel.encodeQuoted(AbstractMarkupModel.java:94)
• org.apache.tapestry5.dom.Attribute.render(Attribute.java:69)
• org.apache.tapestry5.dom.Element.toMarkup(Element.java:313)
• org.apache.tapestry5.dom.Element.writeChildMarkup(Element.java:835)
• org.apache.tapestry5.dom.Element.toMarkup(Element.java:351)
• org.apache.tapestry5.dom.Element.writeChildMarkup(Element.java:835)
• org.apache.tapestry5.dom.Element.toMarkup(Element.java:351)
• org.apache.tapestry5.dom.Element.writeChildMarkup(Element.java:835)
• org.apache.tapestry5.dom.Element.toMarkup(Element.java:351)
• org.apache.tapestry5.dom.Element.writeChildMarkup(Element.java:835)
• org.apache.tapestry5.dom.Element.toMarkup(Element.java:351)
• org.apache.tapestry5.dom.Element.writeChildMarkup(Element.java:835)
• org.apache.tapestry5.dom.Element.toMarkup(Element.java:351)
• org.apache.tapestry5.dom.Element.writeChildMarkup(Element.java:835)
• org.apache.tapestry5.dom.Element.toMarkup(Element.java:351)
• org.apache.tapestry5.dom.Element.writeChildMarkup(Element.java:835)
• org.apache.tapestry5.dom.Element.toMarkup(Element.java:351)
• org.apache.tapestry5.dom.Element.writeChildMarkup(Element.java:835)
• org.apache.tapestry5.dom.Element.toMarkup(Element.java:351)
• org.apache.tapestry5.dom.Element.writeChildMarkup(Element.java:835)
• org.apache.tapestry5.dom.Element.toMarkup(Element.java:351)
• org.apache.tapestry5.dom.Element.writeChildMarkup(Element.java:835)
• org.apache.tapestry5.dom.Element.toMarkup(Element.java:351)
• org.apache.tapestry5.dom.Element.writeChildMarkup(Element.java:835)
• org.apache.tapestry5.dom.Element.toMarkup(Element.java:351)
• org.apache.tapestry5.dom.Element.writeChildMarkup(Element.java:835)
• org.apache.tapestry5.dom.Element.toMarkup(Element.java:351)
• org.apache.tapestry5.dom.Element.writeChildMarkup(Element.java:835)
• org.apache.tapestry5.dom.Element.toMarkup(Element.java:351)
• org.apache.tapestry5.dom.Document.toMarkup(Document.java:163)
• org.apache.tapestry5.dom.Node.toMarkup(Node.java:80)
• org.apache.tapestry5.internal.services.MarkupWriterImpl.toMarkup(MarkupWriterImpl.java:57)
• org.apache.tapestry5.internal.services.PageResponseRendererImpl.renderPageResponse(PageResponseRendererImpl.java:67)
• $PageResponseRenderer_12085541484.renderPageResponse($PageResponseRenderer_12085541484.java)

The real question is: how can the value ever be null? Adding an attribute that's null, or overriding an attribute to null, should remove it from the list.