From a64330710821cf5735d7013111b29a8e53618eed Mon Sep 17 00:00:00 2001
From: Uma Roy <uma.roy.us@gmail.com>
Date: Thu, 7 Sep 2023 17:41:52 -0700
Subject: [PATCH] Fixes

---
 plonky2/src/plonk/circuit_builder.rs | 11 ++++++-----
 plonky2/src/plonk/circuit_data.rs    |  2 +-
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/plonky2/src/plonk/circuit_builder.rs b/plonky2/src/plonk/circuit_builder.rs
index 5a9eb3b2..bd436f2c 100644
--- a/plonky2/src/plonk/circuit_builder.rs
+++ b/plonky2/src/plonk/circuit_builder.rs
@@ -1026,18 +1026,19 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         let max_fft_points = 1 << (degree_bits + max(rate_bits, log2_ceil(quotient_degree_factor)));
         let fft_root_table = fft_root_table(max_fft_points);
 
-        let mut constants_sigmas_commitment = PolynomialBatch::<F, C, D>::default();
-        if commit_to_sigma {
+        let constants_sigmas_commitment = if commit_to_sigma {
             let constants_sigmas_vecs = [constant_vecs, sigma_vecs.clone()].concat();
-            constants_sigmas_commitment = PolynomialBatch::<F, C, D>::from_values(
+            PolynomialBatch::<F, C, D>::from_values(
                 constants_sigmas_vecs,
                 rate_bits,
                 PlonkOracle::CONSTANTS_SIGMAS.blinding,
                 cap_height,
                 &mut timing,
                 Some(&fft_root_table),
-            );
-        }
+            )
+        } else {
+            PolynomialBatch::<F, C, D>::default()
+        };
 
         // Map between gates where not all generators are used and the gate's number of used generators.
         let incomplete_gates = self
diff --git a/plonky2/src/plonk/circuit_data.rs b/plonky2/src/plonk/circuit_data.rs
index 0b96c527..26094679 100644
--- a/plonky2/src/plonk/circuit_data.rs
+++ b/plonky2/src/plonk/circuit_data.rs
@@ -111,7 +111,7 @@ impl CircuitConfig {
     }
 }
 
-/// Circuit data required by the prover or the verifier.
+/// Mock circuit data to only do witness generation without generating a proof.
 #[derive(Eq, PartialEq, Debug)]
 pub struct MockCircuitData<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
 {