X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/be3ed0da8343bdbd68665bef9a9bb096865bea04..d9e0300f903aa7cfb85a94480ad544082a7a6c35:/terminal.c

diff --git a/terminal.c b/terminal.c
index 19d5a750..4f0d8225 100644
--- 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;