Dashboard portlets not deleted when project is deleted

When a project is deleted, its associated filters are also deleted (at least in 2.5), but portlets that depend on the project (eg. stats portlet) are not deleted.

While this is not a critical problem (the dashboard doesn't break), one gets errors in the log:

[ERROR] ServletValueStack - -METHOD: "hasProjectPermission", exception: <java.lang.NullPointerException>java.lang.NullPointerException
at webwork.util.ValueStack.findMethod(ValueStack.java:743)
at webwork.util.ValueStack.findValue(ValueStack.java:382)
at webwork.expr.Parser.findValue(Parser.java:332)
at webwork.expr.Parser.comparative_expression(Parser.java:224)
at webwork.expr.Parser.logical_and_expression(Parser.java:173)
at webwork.expr.Parser.test(Parser.java:143)
at webwork.util.ValueStack.test(ValueStack.java:131)
at webwork.view.taglib.IfTag.doStartTag(IfTag.java:38)
at org.apache.jsp.projectstats_jsp._jspx_meth_webwork_if_0(projectstats_jsp.java:137)
at org.apache.jsp.projectstats_jsp._jspx_meth_webwork_property_0(projectstats_jsp.java:111)
at org.apache.jsp.projectstats_jsp._jspService(projectstats_jsp.java:79)