https://github.com/onetrueawk/awk/pull/196

From 75c017ca09a70e14a862f7285cf91bb87ec1f443 Mon Sep 17 00:00:00 2001
From: "Todd C. Miller" <Todd.Miller@sudo.ws>
Date: Mon, 18 Sep 2023 17:34:34 -0600
Subject: [PATCH 1/2] Fix a bad cast to char * that causes incorrect results on
 big endian.

Now that awk stores chars as int we need to cast the Node * to int *.
--- a/b.c
+++ b/b.c
@@ -527,7 +527,7 @@ int first(Node *p)	/* collects initially active leaves of p into setvec */
 			setvec[lp] = 1;
 			setcnt++;
 		}
-		if (type(p) == CCL && (*(char *) right(p)) == '\0')
+		if (type(p) == CCL && (*(int *) right(p)) == 0)
 			return(0);		/* empty CCL */
 		return(1);
 	case PLUS:

From 0048c96e94c732c6fb2ebe50eeb3450c1672fe0f Mon Sep 17 00:00:00 2001
From: "Todd C. Miller" <Todd.Miller@sudo.ws>
Date: Thu, 21 Sep 2023 11:20:16 -0600
Subject: [PATCH 2/2] Use cclenter("") to construct an empty CCL, not
 tostring("").

We need to store a UTF-32 string, not a UTF-8 string, for consistency
with the other CCL code.  Fixes an out-of-bounds read of an empty
CCL.
--- a/b.c
+++ b/b.c
@@ -945,7 +945,7 @@ Node *primary(void)
 		rtok = relex();
 		if (rtok == ')') {	/* special pleading for () */
 			rtok = relex();
-			return unary(op2(CCL, NIL, (Node *) tostring("")));
+			return unary(op2(CCL, NIL, (Node *) cclenter("")));
 		}
 		np = regexp();
 		if (rtok == ')') {
@@ -968,7 +968,7 @@ Node *concat(Node *np)
 		return (concat(op2(CAT, np, primary())));
 	case EMPTYRE:
 		rtok = relex();
-		return (concat(op2(CAT, op2(CCL, NIL, (Node *) tostring("")),
+		return (concat(op2(CAT, op2(CCL, NIL, (Node *) cclenter("")),
 				primary())));
 	}
 	return (np);