msvcrt: __mb_cur_max is not updated in _setmbcp (with testcase) and should not…

dlls/msvcrt/mbcs.c

@@ -911,7 +911,7 @@ int CDECL _ismbckata(unsigned int c)
 int CDECL _ismbblead(unsigned int c)
 {
   /* FIXME: should reference MSVCRT_mbctype */
-  return MSVCRT___mb_cur_max > 1 && MSVCRT_isleadbyte(c);
+  return MSVCRT_isleadbyte(c);
 }
 
 

dlls/msvcrt/tests/string.c

@@ -78,8 +78,10 @@ static void test_swab( void ) {
 static void test_ismbblead(void)
 {
     unsigned int s = '\354';
+    int mb_orig_max = __mb_cur_max;
 
     _setmbcp(936);
+    ok(__mb_cur_max == mb_orig_max, "__mb_cur_max shouldn't be updated (is %d != %d)\n", __mb_cur_max, mb_orig_max);
     todo_wine ok(_ismbblead(s), "got result %d\n", _ismbblead(s));
     _setmbcp(1252);
 }