cocos lua app will crash if lua include paths order is incorrect！！！

[sonyps5201314]

• cocos2d-x version: 3.17.2 git latest
• devices test on:windows 8.1
• developing environments
  • VS version:vs 2017 latest

Steps to Reproduce:

1. create vs client game project,include path is $(EngineRoot)external\lua\lua;$(EngineRoot)external\lua\luajit\include
2. call lua_getstack(L, depth, &entry); next the program will crash with memory error.
   fix solution:fix #define LUA_IDSIZE 512 in frameworks\cocos2d-x\external\lua\lua\luaconf.h as same to frameworks\cocos2d-x\external\lua\luajit\include\luaconf.h

我再用中文说一遍嘛，怕你们不懂，如果用户创建的游戏工程包含路径中$(EngineRoot)external\lua\lua在$(EngineRoot)external\lua\luajit\include前面因为都有luaconf.h这个文件，所以VS的编译器会使用第一个目录下的luaconf.h即frameworks\cocos2d-x\external\lua\lua\luaconf.h，但是这个目录下的LUA_IDSIZE宏的定义和luajit下的是不同的，cocos的patch文件只修改了luajit中的这个宏值为512，所以一旦调用lua_Debug结构体相关的函数如lua_getstack，lua_getinfo等，luajit内部就会写入512个字节到lua_Debug的short_src字段，而这里被定义成了60个大小和luajit内部中的不一致，所以导致了写多了字节进去，进而导致其他变量的缓冲区被覆盖了，进而可能引起崩溃，甚至远程代码执行漏洞。所以请两个地方都同步修改成512就没事了，或者修改回原来的60，即去掉cocos的这个patch。

[minggo]

@sonyps5201314 which patch cause the problem?

[minggo]

Ok, i see the difference between the two luaconf.h, i will track the log to see why they are different.

[minggo]

I track the log, it seems it is modified by luajit itself, no by us. And i think developers should not include lua and luajit at the same time. It is dangerous, and i think there will be many warnings.

[sonyps5201314]

this path is this file: https://github.com/cocos2d/cocos2d-x-3rd-party-libs-src/blob/v3/contrib/src/luajit/luajit-v2.1.0-beta3.patch ,and other two patch files in the same folds.
but the template project file was use the standand lua include files not the luajit includes. so every projects will occur this problem if them call these lua debug functions like above lua_getstack，lua_getinfo.

[minggo]

Yep, i din't notice it before. And i don't know why the patch is needed. I think you are right, we should not use it. And should not include both header files in the template.

[sonyps5201314]

yep，cocos use the standand lua include files，but use luajit import library and dll as default.

[minggo]

@PatriceJiang please update lujit and remove lua library as all platforms uses luajit.

[minggo]

#20277 fix the header file issue. And @PatriceJiang will rebuild luajit without the patch.

[sonyps5201314]

thanks

[minggo]

luajit is updated in #20306.