#vulnerable code 
                             public int run(ItemCollection adocumentContext, ItemCollection adocumentActivity) throws PluginException {
		documentContext = adocumentContext;
		// evaluate new items....
		ItemCollection evalItemCollection = new ItemCollection();
		evalItemCollection=adocumentContext=evaluateWorkflowResult(adocumentActivity,documentContext);
		// copy values
		documentContext.replaceAllItems(evalItemCollection.getAllItems());
		return Plugin.PLUGIN_OK;
	} 
                            #location 7 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                             public int run(ItemCollection adocumentContext, ItemCollection adocumentActivity) throws PluginException {
		documentContext = adocumentContext;
		// evaluate new items....
		ItemCollection evalItemCollection = new ItemCollection();
		evalItemCollection=adocumentContext=evaluateWorkflowResult(adocumentActivity,documentContext);
		// copy values
		if (evalItemCollection!=null) {
			documentContext.replaceAllItems(evalItemCollection.getAllItems());
		}
		return Plugin.PLUGIN_OK;
	}