msvcrt: Set *end to NULL when strtod is called with NULL pointer string.

dlls/msvcrt/string.c

@@ -317,8 +317,11 @@ static double strtod_helper(const char *str, char **end, MSVCRT__locale_t locale
 
     if(err)
         *err = 0;
-    else
-        if(!MSVCRT_CHECK_PMT(str != NULL)) return 0;
+    else if(!MSVCRT_CHECK_PMT(str != NULL)) {
+        if (end)
+            *end = NULL;
+        return 0;
+    }
 
     if(!locale)
         locinfo = get_locinfo();

dlls/msvcrt/tests/string.c

@@ -1694,7 +1694,7 @@ static void test__strtod(void)
         d = strtod(NULL, &end);
         ok(almost_equal(d, 0.0), "d = %lf\n", d);
         ok(errno == EINVAL, "errno = %x\n", errno);
-        todo_wine ok(!end, "incorrect end ptr %p\n", end);
+        ok(!end, "incorrect end ptr %p\n", end);
 
         errno = EBADF;
         d = p__strtod_l(NULL, NULL, NULL);