From d4b6c0e1a2084335b89f0e16baabfba829eecf8c Mon Sep 17 00:00:00 2001
From: Jim Posen <jim.posen@gmail.com>
Date: Mon, 19 Aug 2019 14:04:41 +0200
Subject: [PATCH] Use expect to remove unreachable break.

---
 zcash_proofs/src/circuit/pedersen_hash.rs | 40 ++++++++++-------------
 1 file changed, 18 insertions(+), 22 deletions(-)

diff --git a/zcash_proofs/src/circuit/pedersen_hash.rs b/zcash_proofs/src/circuit/pedersen_hash.rs
index 3cd9367..9558acc 100644
--- a/zcash_proofs/src/circuit/pedersen_hash.rs
+++ b/zcash_proofs/src/circuit/pedersen_hash.rs
@@ -72,32 +72,28 @@ where
             window_i += 1;
         }
 
-        match segment_result {
-            Some(segment_result) => {
-                // Convert this segment into twisted Edwards form.
-                let segment_result = segment_result.into_edwards(
-                    cs.namespace(|| format!("conversion of segment {} into edwards", segment_i)),
+        let segment_result = segment_result.expect(
+            "bits is not exhausted due to while condition;
+                    thus there must be a segment window;
+                    thus there must be a segment result",
+        );
+
+        // Convert this segment into twisted Edwards form.
+        let segment_result = segment_result.into_edwards(
+            cs.namespace(|| format!("conversion of segment {} into edwards", segment_i)),
+            params,
+        )?;
+
+        match edwards_result {
+            Some(ref mut edwards_result) => {
+                *edwards_result = segment_result.add(
+                    cs.namespace(|| format!("addition of segment {} to accumulator", segment_i)),
+                    edwards_result,
                     params,
                 )?;
-
-                match edwards_result {
-                    Some(ref mut edwards_result) => {
-                        *edwards_result = segment_result.add(
-                            cs.namespace(|| {
-                                format!("addition of segment {} to accumulator", segment_i)
-                            }),
-                            edwards_result,
-                            params,
-                        )?;
-                    }
-                    None => {
-                        edwards_result = Some(segment_result);
-                    }
-                }
             }
             None => {
-                // We didn't process any new bits.
-                break;
+                edwards_result = Some(segment_result);
             }
         }