From a08710ed0cb5ae8850f2f184c3cf25959d3008b6 Mon Sep 17 00:00:00 2001
From: "Arnold D. Robbins" <arnold@skeeve.com>
Date: Tue, 18 Aug 2026 17:45:22 +0300
Subject: [PATCH] Small parsing speed improvement.

---
 parse.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/parse.c b/parse.c
index 14608be..1d59d1f 100644
--- a/parse.c
+++ b/parse.c
@@ -217,6 +217,7 @@ Node *pa2stat(Node *a, Node *b, Node *c)	/* pat, pat {...} */
 Node *linkum(Node *a, Node *b)
 {
 	Node *c;
+	static Node *prev_head, *prev_tail;	/* auto-init to NULL */
 
 	if (errorflag)	/* don't link things that are wrong */
 		return a;
@@ -224,9 +225,17 @@ Node *linkum(Node *a, Node *b)
 		return(b);
 	else if (b == NULL)
 		return(a);
-	for (c = a; c->nnext != NULL; c = c->nnext)
-		;
-	c->nnext = b;
+
+	if (prev_head == a) {
+		prev_tail->nnext = b;
+		prev_tail = b;
+	} else {
+		for (c = a; c->nnext != NULL; c = c->nnext)
+			;
+		c->nnext = b;
+		prev_head = a;
+		prev_tail = b;
+	}
 	return(a);
 }