From bc5b0254d0b86c4b11637de14dab55e191388dc5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sigrid=20Solveig=20Hafl=C3=ADnud=C3=B3ttir?=
 <ftrvxmtrx@gmail.com>
Date: Mon, 28 Mar 2022 17:23:04 +0000
Subject: [PATCH] pc: do not access out of bounds array element

---
 sys/src/cmd/pc.y | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sys/src/cmd/pc.y b/sys/src/cmd/pc.y
index 5bbea3212..8e0fedf32 100644
--- a/sys/src/cmd/pc.y
+++ b/sys/src/cmd/pc.y
@@ -636,7 +636,7 @@ yylex(void)
 		yylval.sym = getsym(buf, 1);
 		return LSYMB;
 	}
-	if(c < 128 && (kw = optab[c], kw != nil)){
+	if(c >= 0 && c < 128 && (kw = optab[c], kw != nil)){
 		b = Bgetc(in);
 		for(; kw->name[0] == c; kw++)
 			if(kw->name[0] == b)