i am optimizing a jar with proguard, but it crashes after optimization.
here is my proguard task:

```
    <proguard>
        -injars     ${dist}/${jarname}
        -outjars    ${dist}-proguard/${jarname}

        -target 5

        -libraryjars '${java.home}/lib/rt.jar'

        -dontobfuscate            
        -optimizationpasses 4
        -overloadaggressively
        -repackageclasses ''
        -allowaccessmodification

        -keep public class * {
            public static void main(java.lang.String[]);
        }
    </proguard>

```

as soon as i put in the -dontoptimize option, it works.

according to the stack of the exception it crashes when accessing a static public member of a class with a nullpointer. here is the code:

```
public static Texture ring, dust, spikering, thinring, crystal, clouds;

public static void init() {
    Field [] fields = TexturePool.class.getDeclaredFields();

    for (Field field : fields) {
        if(field.getType() == Texture.class) {
            field.set( null, /*imagine new object here*/ );
        }
    }
}

```

thanks!