I have setup a project to test the capability of CodeQL，to test taint tracking ablitity

here is my project
```
https://github.com/hatface/codeql_cap_evalution
```

here is the test result
```
https://github.com/hatface/codeql_cap_evalution/blob/main/CodeQL_Capacibility_Test_Result.md
```

here is the CodeQL Query
```cpp
https://github.com/hatface/codeql_cap_evalution/blob/main/taint_cap_test.ql
```

and the case5 is failed

QUESTION：
how to fix the situation using ```isAdditionalTaintStep```

从链接的 CodeQL_Capacibility_Test_Result.md 开始，将失败的 case5 与 taint_cap_test.ql 中的查询进行比较。跟踪报告的 taint 路径，并检查 isAdditionalTaintStep 在何处生效。完成的标准是 case5 有记录在案的解决方案，并且查询产生预期结果。

由索引模型根据 Issue 内容生成。