msvcrt: Use mbtowc/wctomb for string conversion in printf.

dlls/msvcrt/msvcrt.h

@@ -1103,6 +1103,7 @@ int            __cdecl _ismbblead_l(unsigned int, MSVCRT__locale_t);
 int            __cdecl _ismbclegal(unsigned int c);
 int            __cdecl _ismbstrail(const unsigned char* start, const unsigned char* str);
 int            __cdecl MSVCRT_mbtowc(MSVCRT_wchar_t*,const char*,MSVCRT_size_t);
+int            __cdecl MSVCRT_mbtowc_l(MSVCRT_wchar_t*,const char*,MSVCRT_size_t,MSVCRT__locale_t);
 MSVCRT_size_t  __cdecl MSVCRT_mbstowcs(MSVCRT_wchar_t*,const char*,MSVCRT_size_t);
 MSVCRT_size_t  __cdecl MSVCRT__mbstowcs_l(MSVCRT_wchar_t*, const char*, MSVCRT_size_t, MSVCRT__locale_t);
 MSVCRT_size_t  __cdecl MSVCRT_wcstombs(char*,const MSVCRT_wchar_t*,MSVCRT_size_t);
@@ -1128,6 +1129,7 @@ MSVCRT_size_t __cdecl MSVCRT_strnlen(const char *,MSVCRT_size_t);
 MSVCRT_size_t __cdecl MSVCRT_wcsnlen(const MSVCRT_wchar_t*,MSVCRT_size_t);
 MSVCRT_wchar_t*** __cdecl MSVCRT___p__wenviron(void);
 INT     __cdecl MSVCRT_wctomb(char*,MSVCRT_wchar_t);
+int     __cdecl MSVCRT__wctomb_l(char*, MSVCRT_wchar_t, MSVCRT__locale_t);
 char*   __cdecl MSVCRT__strdate(char* date);
 char*   __cdecl MSVCRT__strtime(char* date);
 int     __cdecl _setmbcp(int);

dlls/msvcrt/tests/printf.c

@@ -106,6 +106,7 @@ static void test_sprintf( void )
     double pnumber=789456123;
     int x, r;
     WCHAR wide[] = { 'w','i','d','e',0};
+    WCHAR buf_w[2];
 
     format = "%+#23.15e";
     r = sprintf(buffer,format,pnumber);
@@ -786,6 +787,17 @@ static void test_sprintf( void )
     ok(r==0, "r = %d\n", r);
     ok(!strcmp(buffer, ""), "failed: \"%s\"\n", buffer);
 
+    format = "a%Cb";
+    r = sprintf(buffer, format, 0x3042);
+    ok(r==2, "r = %d\n", r);
+    ok(!strcmp(buffer, "ab"), "failed: \"%s\"\n", buffer);
+
+    format = "%S";
+    buf_w[0] = 0x3042;
+    buf_w[1] = 0;
+    r = sprintf(buffer, format, buf_w);
+    ok(r==-1 || broken(!r), "r = %d\n", r);
+
     if(!setlocale(LC_ALL, "Japanese_Japan.932")) {
         win_skip("Japanese_Japan.932 locale not available\n");
         return;