From 899569f653c33e8e934a4bfc194f205d5f80de6c Mon Sep 17 00:00:00 2001
From: Serhiy Storchaka <storchaka@gmail.com>
Date: Tue, 15 Sep 2026 13:31:21 +0300
Subject: [PATCH] Fix PDC_wcstombs() for an output that exactly fills the
 buffer

wcstombs() returns n when the converted string fills all n bytes;
that is not an error.  Also compare the result with (size_t)-1
instead of casting it to int.  Fixes #390.
---
 pdcurses/util.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pdcurses/util.c b/pdcurses/util.c
index bd00fb50..8c3105e5 100644
--- a/pdcurses/util.c
+++ b/pdcurses/util.c
@@ -499,8 +499,8 @@ size_t PDC_wcstombs(char *dest, const wchar_t *src, size_t n)
 # else
     size_t i = wcstombs(dest, src, n);
 # endif
-    assert( -1 != (int)i && i < n);
-    if( (int)i < 0 || i >= n)        /* invalid sequence or insufficient space */
+    assert( i == (size_t)-1 || i <= n);
+    if( i == (size_t)-1)             /* invalid sequence */
         *dest = '\0';
     else
         dest[i] = '\0';