From d60154d893218d4da9560beab0f2be6fbc902647 Mon Sep 17 00:00:00 2001
From: Igor Artamonov <igor@artamonov.ru>
Date: Tue, 16 Feb 2021 17:15:00 -0500
Subject: [PATCH] problem: nullpointer stacktrace if json is just "null"

---
 .../dshackle/upstream/ethereum/CacheRequested.kt    |  3 ++-
 .../upstream/ethereum/CacheRequestedSpec.groovy     | 13 +++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/CacheRequested.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/CacheRequested.kt
index e824f808..da386049 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/CacheRequested.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/CacheRequested.kt
@@ -46,7 +46,8 @@ class CacheRequested(
         if (params.size != 1) {
             return
         }
-        val parsed = Global.objectMapper.readValue(json, TransactionReceiptJson::class.java)
+        // note: json could be a `null` value
+        val parsed = Global.objectMapper.readValue(json, TransactionReceiptJson::class.java) ?: return
         val value = DefaultContainer<TransactionReceiptJson>(
                 TxId.from(parsed.transactionHash),
                 BlockId.from(parsed.blockHash),
diff --git a/src/test/groovy/io/emeraldpay/dshackle/upstream/ethereum/CacheRequestedSpec.groovy b/src/test/groovy/io/emeraldpay/dshackle/upstream/ethereum/CacheRequestedSpec.groovy
index 9a97b5d5..2b93c5dc 100644
--- a/src/test/groovy/io/emeraldpay/dshackle/upstream/ethereum/CacheRequestedSpec.groovy
+++ b/src/test/groovy/io/emeraldpay/dshackle/upstream/ethereum/CacheRequestedSpec.groovy
@@ -42,4 +42,17 @@ class CacheRequestedSpec extends Specification {
         })
     }
 
+    def "Ignore null"() {
+        setup:
+        def caches = Mock(Caches)
+        CacheRequested instance = new CacheRequested(caches)
+        def json = 'null'.bytes
+
+        when:
+        instance.cacheTxReceipt(["0x5929b36be4586c57bd87dfb7ea6be3b985c1f527fa3d69d221604b424aeb4197"], json)
+
+        then:
+        0 * caches.cacheReceipt(_, _)
+    }
+
 }