[UCRT] Import Microsoft.Windows.SDK.CRTSource version 10.0.22621.3

Imported from https://www.nuget.org/packages/Microsoft.Windows.SDK.CRTSource/10.0.22621.3
License: MIT

sdk/lib/ucrt/mbstring/mbsnbcpy.cpp

@@ -0,0 +1,103 @@
+/***
+*mbsnbcpy.c - Copy one string to another, n bytes only (MBCS)
+*
+*       Copyright (c) Microsoft Corporation.  All rights reserved.
+*
+*Purpose:
+*       Copy one string to another, n bytes only (MBCS)
+*
+*******************************************************************************/
+#ifndef _MBCS
+    #error This file should only be compiled with _MBCS defined
+#endif
+
+#include <corecrt_internal_mbstring.h>
+#include <locale.h>
+#include <string.h>
+
+#pragma warning(disable:__WARNING_POTENTIAL_BUFFER_OVERFLOW_NULLTERMINATED) // 26018
+
+/***
+* _mbsnbcpy - Copy one string to another, n bytes only (MBCS)
+*
+*Purpose:
+*       Copies exactly cnt bytes from src to dst.  If strlen(src) < cnt, the
+*       remaining character are padded with null bytes.  If strlen >= cnt, no
+*       terminating null byte is added.  2-byte MBCS characters are handled
+*       correctly.
+*
+*Entry:
+*       unsigned char *dst = destination for copy
+*       unsigned char *src = source for copy
+*       int cnt = number of bytes to copy
+*
+*Exit:
+*       returns dst = destination of copy
+*
+*Exceptions:
+*       Input parameters are validated. Refer to the validation section of the function.
+*
+*******************************************************************************/
+
+#pragma warning(suppress:6101) // Returning uninitialized memory '*dst'.  A successful path through the function does not set the named _Out_ parameter.
+unsigned char * __cdecl _mbsnbcpy_l(
+        unsigned char *dst,
+        const unsigned char *src,
+        size_t cnt,
+        _locale_t plocinfo
+        )
+{
+
+        unsigned char *start = dst;
+        _LocaleUpdate _loc_update(plocinfo);
+
+        /* validation section */
+        _VALIDATE_RETURN(dst != nullptr || cnt == 0, EINVAL, nullptr);
+        _VALIDATE_RETURN(src != nullptr || cnt == 0, EINVAL, nullptr);
+
+        _BEGIN_SECURE_CRT_DEPRECATION_DISABLE
+        if (_loc_update.GetLocaleT()->mbcinfo->ismbcodepage == 0)
+#pragma warning(suppress:__WARNING_BANNED_API_USAGE)
+            return (unsigned char *)strncpy((char *)dst, (const char *)src, cnt);
+        _END_SECURE_CRT_DEPRECATION_DISABLE
+
+        while (cnt) {
+
+            cnt--;
+            if ( _ismbblead_l(*src, _loc_update.GetLocaleT()) ) {
+                *dst++ = *src++;
+                if (!cnt) {
+                    dst[-1] = '\0';
+                    break;
+                }
+                cnt--;
+                if ((*dst++ = *src++) == '\0') {
+                    dst[-2] = '\0';
+                    break;
+                }
+            }
+
+            else
+                if ((*dst++ = *src++) == '\0')
+                    break;
+
+        }
+
+        /* pad with nulls as needed */
+
+        while (cnt--)
+            *dst++ = '\0';
+
+#pragma warning(suppress:__WARNING_POSTCONDITION_NULLTERMINATION_VIOLATION) // 26036
+        return start;
+}
+unsigned char * (__cdecl _mbsnbcpy)(
+        unsigned char *dst,
+        const unsigned char *src,
+        size_t cnt
+        )
+{
+    _BEGIN_SECURE_CRT_DEPRECATION_DISABLE
+    return _mbsnbcpy_l(dst, src, cnt, nullptr);
+    _END_SECURE_CRT_DEPRECATION_DISABLE
+}