[GROOVY-4458] NPE in org.codehaus.groovy.runtime.dgmimpl.NumberNumberPlus$DoubleInteger

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.7.5
• Fix Version/s: 1.8.9, 2.0.7, 2.1.1
• Environment: Windows XP SP3, JDK 1.6.0
• Assignee: Jochen Theodorou
• Reporter: Uwe Kirsch
• Created: 05/Oct/10 06:54
• Updated: 16/Feb/13 00:47
• Resolved: 28/Jan/13 14:21

Description

We enhance the NullObject to have a more graceful null handling.

def emc = new ExpandoMetaClass( org.codehaus.groovy.runtime.NullObject.getNullObject().getClass())
emc.plus = {b -> b}
emc.initialize()
org.codehaus.groovy.runtime.NullObject.getNullObject().setMetaClass(emc)

It works fine except for some variants of array access:
Double[][] a = new Double[10][10]
for (def i = 0; i <= 9; i++ ) {
    for (def j = 0; j <= 9; j++ ) {
        println("i=$i j=$j a[0][i]=$a[0][i]")
        a[0][i] = a[0][i] + 1
    }
}

We get a NPE:

java.lang.NullPointerException
    at org.codehaus.groovy.runtime.dgmimpl.NumberNumberPlus$DoubleInteger.call(NumberNumberPlus.java:170)
    at ConsoleScript6.run(ConsoleScript6:10)
    at groovy.lang.GroovyShell.runScriptOrMainOrTestOrRunnable(GroovyShell.java:264)
    at groovy.lang.GroovyShell.run(GroovyShell.java:513)
    at groovy.lang.GroovyShell.run(GroovyShell.java:170)
    at groovy.lang.GroovyShell$run$0.call(Unknown Source)
    at groovy.ui.Console$_runScriptImpl_closure16.doCall(Console.groovy:890)
    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.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:88)
    at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:233)
    at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:273)
    at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:886)
    at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.callCurrent(PogoMetaClassSite.java:66)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:149)
    at groovy.ui.Console$_runScriptImpl_closure16.doCall(Console.groovy)
    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.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:88)
    at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:233)
    at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:273)
    at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:886)
    at groovy.lang.Closure.call(Closure.java:276)
    at groovy.lang.Closure.call(Closure.java:271)
    at groovy.lang.Closure.run(Closure.java:354)
    at java.lang.Thread.run(Thread.java:619) 

A script to reproduce this in the GroovyConsole is attached.