===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/less/filename.c,v
retrieving revision 1.26
retrieving revision 1.27
diff -u -r1.26 -r1.27
--- src/usr.bin/less/filename.c	2017/10/29 17:10:55	1.26
+++ src/usr.bin/less/filename.c	2019/02/26 11:01:54	1.27
@@ -348,7 +348,7 @@
 	pend = &data[n];
 	for (p = data; p < pend; ) {
 		LWCHAR c = step_char(&p, +1, pend);
-		if (ctldisp == OPT_ONPLUS && IS_CSI_START(c)) {
+		if (ctldisp == OPT_ONPLUS && c == ESC) {
 			do {
 				c = step_char(&p, +1, pend);
 			} while (p < pend && is_ansi_middle(c));