Arguments to ctype functions are required to be either EOF or representable

[u/mdw/putty] / terminal.c

diff --git a/terminal.c b/terminal.c
index 19d5a75..4f0d822 100644 (file)
--- a/terminal.c
+++ b/terminal.c
@@ -5942,7 +5942,7 @@ void term_key(Terminal *term, Key_Sym keysym, wchar_t *text, size_t tlen,
                if (modifiers & PKM_CONTROL)
                    c &= 0x1f;
                else if (modifiers & PKM_SHIFT)
-                   c = toupper(c);
+                       c = toupper((unsigned char)c);
            }
            *p++ = c;
            goto done;