[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/mbsnbcat.cpp

@@ -0,0 +1,116 @@
+/***
+*mbsnbcat.c - concatenate string2 onto string1, max length n bytes
+*
+*       Copyright (c) Microsoft Corporation.  All rights reserved.
+*
+*Purpose:
+*       defines mbsnbcat() - concatenate maximum of n bytes
+*
+*******************************************************************************/
+#ifndef _MBCS
+    #error This file should only be compiled with _MBCS defined
+#endif
+
+#include <corecrt_internal.h>
+#include <corecrt_internal_mbstring.h>
+#include <locale.h>
+#include <string.h>
+
+
+/***
+* _mbsnbcat - concatenate max cnt bytes onto dst
+*
+*Purpose:
+*       Concatenates src onto dst, with a maximum of cnt bytes copied.
+*       Handles 2-byte MBCS characters correctly.
+*
+*Entry:
+*       unsigned char *dst - string to concatenate onto
+*       unsigned char *src - string to concatenate from
+*       int cnt - number of bytes to copy
+*
+*Exit:
+*       returns dst, with src (at least part) concatenated on
+*
+*Exceptions:
+*       Input parameters are validated. Refer to the validation section of the function.
+*
+*******************************************************************************/
+
+extern "C" unsigned char * __cdecl _mbsnbcat_l(
+        unsigned char *dst,
+        const unsigned char *src,
+        size_t cnt,
+        _locale_t plocinfo
+        )
+{
+        unsigned char *start;
+
+        if (!cnt)
+                return(dst);
+
+        /* validation section */
+        _VALIDATE_RETURN(dst != nullptr, EINVAL, nullptr);
+        _VALIDATE_RETURN(src != nullptr, EINVAL, nullptr);
+
+        _LocaleUpdate _loc_update(plocinfo);
+
+        _BEGIN_SECURE_CRT_DEPRECATION_DISABLE
+        if (_loc_update.GetLocaleT()->mbcinfo->ismbcodepage == 0)
+            return (unsigned char *)strncat((char *)dst, (const char *)src, cnt);
+        _END_SECURE_CRT_DEPRECATION_DISABLE
+
+        start = dst;
+        while (*dst++)
+                ;
+        --dst;          // dst now points to end of dst string
+
+        /* if last char in string is a lead byte, back up pointer */
+        if ( dst!=start && _mbsbtype_l(start, (int) ((dst - start) - 1), _loc_update.GetLocaleT()) == _MBC_LEAD )
+        {
+            --dst;
+        }
+
+        /* copy over the characters */
+
+        while (cnt--) {
+
+            if ( _ismbblead_l(*src, _loc_update.GetLocaleT()) ) {
+                *dst++ = *src++;
+                if (cnt == 0) {   /* write null if cnt exhausted */
+                    dst[-1] = '\0';
+                    break;
+                }
+                cnt--;
+                if ((*dst++ = *src++)=='\0') { /* or if no trail byte */
+                    dst[-2] = '\0';
+                    break;
+                }
+            }
+            else if ((*dst++ = *src++) == '\0')
+                break;
+
+        }
+
+        if ( dst!=start && _mbsbtype_l(start, (int) ((dst - start) - 1), _loc_update.GetLocaleT()) == _MBC_LEAD )
+        {
+            dst[-1] = '\0';
+        }
+        else
+        {
+            *dst = '\0';
+        }
+
+        return(start);
+}
+
+extern "C" unsigned char * (__cdecl _mbsnbcat)(
+        unsigned char *dst,
+        const unsigned char *src,
+        size_t cnt
+        )
+{
+    _BEGIN_SECURE_CRT_DEPRECATION_DISABLE
+    return _mbsnbcat_l(dst, src, cnt, nullptr);
+    _END_SECURE_CRT_DEPRECATION_DISABLE
+}