msvcrt: Added space for nullbyte in size returned by wcstombs_s and mbstowcs_s.

dlls/msvcrt/mbcs.c

@@ -1900,7 +1900,7 @@ int CDECL MSVCRT__mbstowcs_s_l(MSVCRT_size_t *ret, MSVCRT_wchar_t *wcstr,
     if(!wcstr && !size) {
         conv = MSVCRT__mbstowcs_l(NULL, mbstr, 0, locale);
         if(ret)
-            *ret = conv;
+            *ret = conv+1;
         return 0;
     }
 

dlls/msvcrt/tests/string.c

@@ -1337,6 +1337,10 @@ static void test_mbstowcs(void)
     ok(ret == 3, "ret = %d\n", (int)ret);
     ok(!memcmp(wOut, wHiragana, sizeof(wHiragana)), "wOut = %s\n", wine_dbgstr_w(wOut));
 
+    err = pmbstowcs_s(&ret, NULL, 0, mHiragana, 1);
+    ok(err == 0, "err = %d\n", err);
+    ok(ret == 3, "ret = %d\n", (int)ret);
+
     err = pwcstombs_s(&ret, mOut, 6, wSimple, _TRUNCATE);
     ok(err == 0, "err = %d\n", err);
     ok(ret == 5, "ret = %d\n", (int)ret);
@@ -1346,6 +1350,10 @@ static void test_mbstowcs(void)
     ok(err == 0, "err = %d\n", err);
     ok(ret == 5, "ret = %d\n", (int)ret);
     ok(!memcmp(mOut, mHiragana, sizeof(mHiragana)), "mOut = %s\n", mOut);
+
+    err = pwcstombs_s(&ret, NULL, 0, wHiragana, 1);
+    ok(err == 0, "err = %d\n", err);
+    ok(ret == 5, "ret = %d\n", (int)ret);
 }
 
 static void test_gcvt(void)

dlls/msvcrt/wcs.c

@@ -341,7 +341,7 @@ MSVCRT_size_t CDECL MSVCRT__wcstombs_s_l(MSVCRT_size_t *ret, char *mbstr,
     if(!mbstr && !size) {
         conv = MSVCRT__wcstombs_l(NULL, wcstr, 0, locale);
         if(ret)
-            *ret = conv;
+            *ret = conv+1;
         return 0;
     }