From 1b6513b954100eed61d0fa2febfd81b13690f536 Mon Sep 17 00:00:00 2001
From: Dennis Kobert <dennis@kobert.dev>
Date: Fri, 21 Aug 2026 16:52:23 +0000
Subject: [PATCH] Treat a free side as one lane in the extend split

---
 node-graph/nodes/gcore/src/record.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/node-graph/nodes/gcore/src/record.rs b/node-graph/nodes/gcore/src/record.rs
index d1a2e3ac95..345ff5ced6 100644
--- a/node-graph/nodes/gcore/src/record.rs
+++ b/node-graph/nodes/gcore/src/record.rs
@@ -148,6 +148,8 @@ fn extend<T>(
 ) -> Result<T, Interrupt> {
 	let split = match base.extent(ctx, Level::Total) {
 		GPoll::Final(Extent::Exactly(count)) => count as u64,
+		// A scalar side joins the concat as a single lane, per `Extent::sum`.
+		GPoll::Final(Extent::Free) => 1,
 		GPoll::Pending => return Err(Interrupt::Pending),
 		_ => return Err(GraphError::new("extend over a non-exact base extent").into()),
 	};