Re: [PATCH v2 0/1] MR6644: Draft: msvcrt: Initialize locale data in new threads.

[Piotr Caban (＠piotr)]

Piotr Caban (@piotr) commented about dlls/msvcrt/thread.c:
> #if _MSVCR_VER >= 140
>          ptr->module = NULL;
>  #endif
> -
>    _setmbcp(_MB_CP_ANSI);

You can't call _setmbcp() here - it might modify other thread mbcp when global (non per-thread) settings are used. The bug is caused by using uninitialized locale cache. The simplest solution is to set:
```c
ptr->cached_locale[0] = 'C';
ptr->cached_locale[1] = 0;
```