[PATCH] mbrtowc: Avoid compare with the result pointer add

[YunQiang Su]

  inbuf = (const unsigned char *) s;
  endbuf = inbuf + n;
  if (__glibc_unlikely (endbuf < inbuf))  // <--- here
    {
      endbuf = (const unsigned char *) ~(uintptr_t) 0;
      if (endbuf == inbuf)
        goto ilseq;
    }

Some compilers (such as clang 20), may treat that the endbuf
greater than inbuf always, as n is a `size_t`, aka `unsigned long`.

Let's use
   if (__glibc_unlikely ((ssize_t)n < 0))
instead.
---
 wcsmbs/mbrtowc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/wcsmbs/mbrtowc.c b/wcsmbs/mbrtowc.c
index 47068ed0e0..124f4b6f0a 100644
--- a/wcsmbs/mbrtowc.c
+++ b/wcsmbs/mbrtowc.c
@@ -71,7 +71,7 @@ __mbrtowc (wchar_t *pwc, const char *s, size_t n, mbstate_t *ps)
   /* Do a normal conversion.  */
   inbuf = (const unsigned char *) s;
   endbuf = inbuf + n;
-  if (__glibc_unlikely (endbuf < inbuf))
+  if (__glibc_unlikely ((ssize_t)n < 0))
     {
       endbuf = (const unsigned char *) ~(uintptr_t) 0;
       if (endbuf == inbuf)
-- 
2.39.5 (Apple Git-154)