From ca1e007a225e1e4c6e8f8da556d1f0e1eef87929 Mon Sep 17 00:00:00 2001
From: guoshichao <guoshichao@xiaomi.com>
Date: Thu, 25 Apr 2024 17:40:43 +0800
Subject: [PATCH] wchar/lib_ungetwc: fix the array access out of bounds error

Signed-off-by: guoshichao <guoshichao@xiaomi.com>
---
 libs/libc/stdio/lib_ungetwc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libs/libc/stdio/lib_ungetwc.c b/libs/libc/stdio/lib_ungetwc.c
index d9f81c6d17e..d3ea7bc53b1 100644
--- a/libs/libc/stdio/lib_ungetwc.c
+++ b/libs/libc/stdio/lib_ungetwc.c
@@ -70,7 +70,7 @@ wint_t ungetwc_unlocked(wint_t wc, FAR FILE *f)
 
   /* Try conversion early so we can fail without locking if invalid */
 
-  if ((l = wctomb(mbc, wc)) < 0)
+  if ((l = wctomb(mbc, wc)) <= 0)
     {
       return WEOF;
     }