detailssummary macro throws an error when referring to a non-existant label

If you have a {detailssummary} macro that points to a non-existant label, the page will no longer render and you will get an error like the following in your logs:

2009-07-02 14:17:25,635 ERROR [http-8080-2] [renderer.v2.components.MacroRendererComponent] processMacro Unexpected error formatting macro: detailssummary
– referer: http://10.110.209.44:8080/display/ECMTEAMSPACE/Home | url: /display/ECMTEAMSPACE/Examples | userName: administrator | action: viewpage | page: 2031649
java.lang.NullPointerException
at com.atlassian.confluence.labels.DefaultLabelManager.getCurrentContentForLabelAndSpace(DefaultLabelManager.java:303)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:304)

See the attached log file for a full stack trace.

Steps to reproduce:

1. add the detailssummary macro to a page and refer to a bogus label as in {detailssummary:label=lkjlkjllkj}
2. save the page