output: #fixed code
                                private Node inlineReturnValue(Node callNode, Node fnNode) {
      Node block = fnNode.getLastChild();
      Node callParentNode = callNode.getParent();
  
      // NOTE: As the normalize pass guarantees globals aren't being
      // shadowed and an expression can't introduce new names, there is
      // no need to check for conflicts.
  
      // Create an argName -> expression map, checking for side effects.
      Map<String, Node> argMap =
          FunctionArgumentInjector.getFunctionCallParameterMap(
              fnNode, callNode, this.safeNameIdSupplier);
  
      Node newExpression;
      if (!block.hasChildren()) {
        Node srcLocation = block;
        newExpression = NodeUtil.newUndefinedNode(srcLocation);
      } else {
        Node returnNode = block.getFirstChild();
        Preconditions.checkArgument(returnNode.getType() == Token.RETURN);
  
        // Clone the return node first.
        Node safeReturnNode = returnNode.cloneTree();
        Node inlineResult = FunctionArgumentInjector.inject(
            null, safeReturnNode, null, argMap);
        Preconditions.checkArgument(safeReturnNode == inlineResult);
        newExpression = safeReturnNode.removeFirstChild();
      }
  
      callParentNode.replaceChild(callNode, newExpression);
      return newExpression;
    }
input: #vulnerable code 
                                private Node inlineReturnValue(Node callNode, Node fnNode) {
      Node block = fnNode.getLastChild();
      Node callParentNode = callNode.getParent();
  
      // NOTE: As the normalize pass guarantees globals aren't being
      // shadowed and an expression can't introduce new names, there is
      // no need to check for conflicts.
  
      // Create an argName -> expression map, checking for side effects.
      Map<String, Node> argMap =
          FunctionArgumentInjector.getFunctionCallParameterMap(
              fnNode, callNode, this.safeNameIdSupplier);
  
      Node newExpression;
      if (!block.hasChildren()) {
        Node srcLocation = block;
        newExpression = NodeUtil.newUndefinedNode(srcLocation);
      } else {
        Node returnNode = block.getFirstChild();
        Preconditions.checkArgument(returnNode.getType() == Token.RETURN);
  
        // Clone the return node first.
        Node safeReturnNode = returnNode.cloneTree();
        Node inlineResult = FunctionArgumentInjector.inject(
            safeReturnNode, null, argMap);
        Preconditions.checkArgument(safeReturnNode == inlineResult);
        newExpression = safeReturnNode.removeFirstChild();
      }
  
      callParentNode.replaceChild(callNode, newExpression);
      return newExpression;
    } 
                              #location 30 
                              #vulnerability type NULL_DEREFERENCE