From 7316cb9d92bd193555d2206a3a0e12edc634020f Mon Sep 17 00:00:00 2001
From: Marek Kotewicz <marek.kotewicz@gmail.com>
Date: Mon, 8 Jan 2018 14:46:29 +0100
Subject: [PATCH] fixed panic when io is not available for export block, closes
 #7486 (#7495)

---
 parity/blockchain.rs | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/parity/blockchain.rs b/parity/blockchain.rs
index b1bf8d4db..84a610ef3 100644
--- a/parity/blockchain.rs
+++ b/parity/blockchain.rs
@@ -591,8 +591,12 @@ fn execute_export(cmd: ExportBlockchain) -> Result<(), String> {
 		}
 		let b = client.block(BlockId::Number(i)).ok_or("Error exporting incomplete chain")?.into_inner();
 		match format {
-			DataFormat::Binary => { out.write(&b).expect("Couldn't write to stream."); }
-			DataFormat::Hex => { out.write_fmt(format_args!("{}", b.pretty())).expect("Couldn't write to stream."); }
+			DataFormat::Binary => {
+				out.write(&b).map_err(|e| format!("Couldn't write to stream. Cause: {}", e))?;
+			}
+			DataFormat::Hex => {
+				out.write_fmt(format_args!("{}", b.pretty())).map_err(|e| format!("Couldn't write to stream. Cause: {}", e))?;
+			}
 		}
 	}