From 82615c67d611bde3d2a7abb4ca4382ba6610e161 Mon Sep 17 00:00:00 2001
From: Tom French <tom@tomfren.ch>
Date: Fri, 19 May 2023 08:53:32 +0100
Subject: [PATCH] feat: allow updating an empty CRS buffer

---
 src/acvm_interop/common_reference_string.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/acvm_interop/common_reference_string.rs b/src/acvm_interop/common_reference_string.rs
index 2122ce00..7841f61a 100644
--- a/src/acvm_interop/common_reference_string.rs
+++ b/src/acvm_interop/common_reference_string.rs
@@ -22,6 +22,12 @@ impl CommonReferenceString for Barretenberg {
         common_reference_string: Vec<u8>,
         circuit: &Circuit,
     ) -> Result<Vec<u8>, Self::Error> {
+        // Treat an empty vector as a request for a fresh CRS.
+        if common_reference_string.is_empty() {
+            return self.generate_common_reference_string(circuit).await;
+        }
+
+        // Otherwise parse CRS and update.
         let mut crs = common_reference_string.try_into()?;
         let constraint_system = &circuit.try_into()?;
         let common_reference_string = self