From 2d60c00fb068178d7cb765133d24241575baff9b Mon Sep 17 00:00:00 2001
From: teor <teor@riseup.net>
Date: Tue, 24 Nov 2020 16:46:02 +1000
Subject: [PATCH] Avoid a panic when downcasting to redjubjub::Error fails
 (#1363)

Instead, format the original error as a string, to provide better
diagnostics.

Temporary fix for #1357, the permanent fix ticket is #1186.
---
 zebra-consensus/src/error.rs | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/zebra-consensus/src/error.rs b/zebra-consensus/src/error.rs
index caa2f2ed..419dc2e8 100644
--- a/zebra-consensus/src/error.rs
+++ b/zebra-consensus/src/error.rs
@@ -67,13 +67,20 @@ pub enum TransactionError {
 
     #[error("bindingSig MUST represent a valid signature under the transaction binding validating key bvk of SigHash")]
     RedJubjub(redjubjub::Error),
+
+    // temporary error type until #1186 is fixed
+    #[error("Downcast from BoxError to redjubjub::Error failed")]
+    InternalDowncastError(String),
 }
 
 impl From<BoxError> for TransactionError {
     fn from(err: BoxError) -> Self {
         match err.downcast::<redjubjub::Error>() {
             Ok(e) => TransactionError::RedJubjub(*e),
-            Err(e) => panic!(e),
+            Err(e) => TransactionError::InternalDowncastError(format!(
+                "downcast to redjubjub::Error failed, original error: {:?}",
+                e
+            )),
         }
     }
 }