From e927afc3838b0e82afe5d1fe791a2931bd73001f Mon Sep 17 00:00:00 2001
From: Sina Mahmoodi <1591639+s1na@users.noreply.github.com>
Date: Wed, 1 Aug 2018 21:56:33 +0200
Subject: [PATCH 1/2] Fix error propagation in iterator

This fixes a minor issue where the iterator, after calling the `run` function, doesn't pass along its error to the callback.
---
 index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/index.js b/index.js
index 5273453..28be3c5 100644
--- a/index.js
+++ b/index.js
@@ -830,7 +830,7 @@ Blockchain.prototype._iterator = function (name, func, cb) {
     async.whilst(
       () => blockNumber,
       run,
-      () => self._saveHeads(cb)
+      (err) => self._saveHeads(() => cb(err))
     )
   })
 

From fcc98b1f9b42efda00000c0c986583227b2caa23 Mon Sep 17 00:00:00 2001
From: Sina Mahmoodi <itz.s1na@gmail.com>
Date: Thu, 2 Aug 2018 11:49:06 +0200
Subject: [PATCH 2/2] Fix _saveHeads cb, add test case

Signed-off-by: Sina Mahmoodi <itz.s1na@gmail.com>
---
 index.js      |  2 +-
 test/index.js | 11 ++++++++++-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/index.js b/index.js
index 28be3c5..191475b 100644
--- a/index.js
+++ b/index.js
@@ -830,7 +830,7 @@ Blockchain.prototype._iterator = function (name, func, cb) {
     async.whilst(
       () => blockNumber,
       run,
-      (err) => self._saveHeads(() => cb(err))
+      (err) => err ? cb(err) : self._saveHeads(cb)
     )
   })
 
diff --git a/test/index.js b/test/index.js
index ced9fa9..b15f8d3 100644
--- a/test/index.js
+++ b/test/index.js
@@ -11,7 +11,7 @@ const testData = require('./testdata.json')
 const BN = require('bn.js')
 
 test('blockchain test', function (t) {
-  t.plan(59)
+  t.plan(61)
   var blockchain = new Blockchain()
   var genesisBlock
   var blocks = []
@@ -220,6 +220,15 @@ test('blockchain test', function (t) {
         done()
       })
     },
+    function iterateError (done) {
+      blockchain.iterator('error', function (block, reorg, cb) {
+        cb(new Error('iterator func error'))
+      }, function (err) {
+        t.ok(err, 'should catch iterator func error')
+        t.equal(err.message, 'iterator func error', 'should return correct error')
+        done()
+      })
+    },
     function iterateEmpty (done) {
       var blockchain = new Blockchain()
       blockchain.validate = false