OpenBSD wcwidth() is sensible and complete so if it returns -1 it means

that a character is not printable, so return to ignoring such
characters.

utf8.c

@@ -119,14 +119,6 @@ utf8_width(wchar_t wc)
 	width = wcwidth(wc);
 	if (width < 0 || width > 0xff) {
 		log_debug("Unicode %04x, wcwidth() %d", wc, width);
-
-		/*
-		 * Many platforms have no width for relatively common
-		 * characters (wcwidth() returns -1); assume width 1 in this
-		 * case and hope for the best.
-		 */
-		if (width < 0)
-			return (1);
 		return (-1);
 	}
 	return (width);