From 2a7168a46baf14a06c06e3aa8abfad400221b820 Mon Sep 17 00:00:00 2001
From: Eugene Kim <ek@harmony.one>
Date: Mon, 9 Sep 2019 20:49:05 -0700
Subject: [PATCH] Fix nil panic if block is not found in database
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This could occur as a result of database corruption or database update
race, where transaction → (blockHash, blockNum, txIndex) lookup succeeds
but the body for blockHash is not (yet) in the database.
---
 core/rawdb/accessors_indexes.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/core/rawdb/accessors_indexes.go b/core/rawdb/accessors_indexes.go
index 1757e5069..6014aec14 100644
--- a/core/rawdb/accessors_indexes.go
+++ b/core/rawdb/accessors_indexes.go
@@ -71,6 +71,14 @@ func ReadTransaction(db DatabaseReader, hash common.Hash) (*types.Transaction, c
 		return nil, common.Hash{}, 0, 0
 	}
 	body := ReadBody(db, blockHash, blockNumber)
+	if body == nil {
+		utils.Logger().Error().
+			Uint64("number", blockNumber).
+			Str("hash", blockHash.Hex()).
+			Uint64("index", txIndex).
+			Msg("block Body referenced missing")
+		return nil, common.Hash{}, 0, 0
+	}
 	tx := body.TransactionAt(int(txIndex))
 	if tx == nil {
 		utils.Logger().Error().