NullPointerException in Diff

[gloeglm]

The implementation of the Diff has quite a glaring missing null check, which produces the following exception in 1.0.0.M1

Caused by: org.springframework.sync.PatchException: Error performing diff:
        at org.springframework.sync.Diff.diff(Diff.java:54) ~[spring-sync-1.0.0.M1.jar!/:1.0.0.M1]
        at REMOVED
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_45]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_45]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_45]
        at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_45]
        at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221) ~[spring-web-4.1.6.RELEASE.jar!/:4.1.6.RELEASE]
        at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137) ~[spring-web-4.1.6.RELEASE.jar!/:4.1.6.RELEASE]
        at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110) ~[spring-webmvc-4.1.6.RELEASE.jar!/:4.1.6.RELEASE]
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:776) ~[spring-webmvc-4.1.6.RELEASE.jar!/:4.1.6.RELEASE]
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:705) ~[spring-webmvc-4.1.6.RELEASE.jar!/:4.1.6.RELEASE]
        at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) ~[spring-webmvc-4.1.6.RELEASE.jar!/:4.1.6.RELEASE]
        at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959) ~[spring-webmvc-4.1.6.RELEASE.jar!/:4.1.6.RELEASE]
        at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893) ~[spring-webmvc-4.1.6.RELEASE.jar!/:4.1.6.RELEASE]
        at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966) ~[spring-webmvc-4.1.6.RELEASE.jar!/:4.1.6.RELEASE]
        ... 41 common frames omitted
Caused by: java.lang.NullPointerException: null
        at org.springframework.sync.Diff.diffNonList(Diff.java:110) ~[spring-sync-1.0.0.M1.jar!/:1.0.0.M1]
        at org.springframework.sync.Diff.diffNonList(Diff.java:116) ~[spring-sync-1.0.0.M1.jar!/:1.0.0.M1]
        at org.springframework.sync.Diff.diff(Diff.java:49) ~[spring-sync-1.0.0.M1.jar!/:1.0.0.M1]
        ... 55 common frames omitted

In the current HEAD it has migrated down one line to line 111 in Diff.java