Next button crashes on search results

Steps to reproduce:

On confluence.atlassian.com, search for something with more than a page of results, then hit next.

[ERROR] Tue Feb 15 00:24:54 CST 2005 [com.opensymphony.xwork.util.CompoundRootAccessor] Caught an Ognl exception while setting property startIndex

Throwable:
ognl.MethodFailedException: Method "setStartIndex" failed for object com.atlassian.confluence.search.actions.SearchSiteAction@90557c [java.lang.NullPointerException]
at ognl.OgnlRuntime.callAppropriateMethod(OgnlRuntime.java:796)
at ognl.OgnlRuntime.setMethodValue(OgnlRuntime.java:937)
at ognl.ObjectPropertyAccessor.setPossibleProperty(ObjectPropertyAccessor.java:76)
at ognl.ObjectPropertyAccessor.setProperty(ObjectPropertyAccessor.java:132)
at ognl.OgnlRuntime.setProperty(OgnlRuntime.java:1629)
at com.opensymphony.xwork.util.CompoundRootAccessor.setProperty(CompoundRootAccessor.java:45)
at ognl.OgnlRuntime.setProperty(OgnlRuntime.java:1629)
at ognl.ASTProperty.setValueBody(ASTProperty.java:105)
at ognl.SimpleNode.evaluateSetValueBody(SimpleNode.java:180)
at ognl.SimpleNode.setValue(SimpleNode.java:230)
at ognl.Ognl.setValue(Ognl.java:476)
at com.opensymphony.xwork.util.OgnlUtil.setValue(OgnlUtil.java:188)
at com.opensymphony.xwork.util.OgnlValueStack.setValue(OgnlValueStack.java:113)
at com.opensymphony.xwork.util.OgnlValueStack.setValue(OgnlValueStack.java:97)
at com.opensymphony.xwork.interceptor.ParametersInterceptor.before(ParametersInterceptor.java:68)
at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:34)
at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:165)
at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:35)
at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:165)