commit e73651f12a406629778f02d8e5acbe2caec0dfc2
from: Hiltjo Posthuma <hiltjo@codemadness.org>
date: Sat Mar 26 16:58:47 2022 UTC

fix UB with the function iscntrl()

From commit 6818e07291f3b2913e687c8ec3d3fe4711724050 by NRK, thanks

commit - 31fa07b9849b0ffbf4b7efb55943f466b3ff160f
commit + e73651f12a406629778f02d8e5acbe2caec0dfc2
blob - 085dc292631e72778c05c31f4c4840d9ab0b0856
blob + 839f6ccd935f2755afa81afc7549ea95bc7b93aa
--- dmenu.c
+++ dmenu.c
@@ -415,7 +415,7 @@ keypress(XKeyEvent *ev)
 	switch(ksym) {
 	default:
 insert:
-		if (!iscntrl(*buf))
+		if (!iscntrl((unsigned char)*buf))
 			insert(buf, len);
 		break;
 	case XK_Delete: