avoid taking external array as-is.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@11285 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/util/VariableResolver.java

@@ -60,7 +60,7 @@ public interface VariableResolver<V> {
         private final VariableResolver<? extends V>[] resolvers;
 
         public Union(VariableResolver<? extends V>... resolvers) {
-            this.resolvers = resolvers;
+            this.resolvers = resolvers.clone();
         }
 
         public Union(Collection<? extends VariableResolver<? extends V>> resolvers) {