From 4a2dd4760b02eebd32ccd564d567aada545812ae Mon Sep 17 00:00:00 2001
From: Gabriel Rodriguez Alsina <gabriel.rodriguez@altoros.com>
Date: Mon, 13 May 2019 20:47:44 -0300
Subject: [PATCH 1/8] (fix) Wrong styles for tokens dropdown

---
 apps/block_scout_web/assets/css/components/_card.scss         | 4 ++--
 apps/block_scout_web/assets/css/components/_dropdown.scss     | 4 ++--
 .../templates/address_token_balance/_token_balances.html.eex  | 4 ++--
 .../templates/address_token_balance/_tokens.html.eex          | 4 ++--
 4 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/apps/block_scout_web/assets/css/components/_card.scss b/apps/block_scout_web/assets/css/components/_card.scss
index 2e2cba08a9..dbaac15664 100644
--- a/apps/block_scout_web/assets/css/components/_card.scss
+++ b/apps/block_scout_web/assets/css/components/_card.scss
@@ -18,8 +18,8 @@ $card-background-1-text-color: #fff !default;
   background-color: $card-background-1;
   color: $card-background-1-text-color;
 
-  a,
-  a:hover {
+  a:not(.dropdown-item),
+  a:not(.dropdown-item):hover {
     color: $card-background-1-text-color;
   }
 }
diff --git a/apps/block_scout_web/assets/css/components/_dropdown.scss b/apps/block_scout_web/assets/css/components/_dropdown.scss
index b603d53fea..c8962c021d 100644
--- a/apps/block_scout_web/assets/css/components/_dropdown.scss
+++ b/apps/block_scout_web/assets/css/components/_dropdown.scss
@@ -60,9 +60,9 @@
 
 .dropdown-search-icon {
   color: $gray-300;
-  left: 0.625rem;
+  left: 8px;
   pointer-events: none;
-  top: 0.5rem;
+  top: 5px;
 }
 
 .dropdown-search-field {
diff --git a/apps/block_scout_web/lib/block_scout_web/templates/address_token_balance/_token_balances.html.eex b/apps/block_scout_web/lib/block_scout_web/templates/address_token_balance/_token_balances.html.eex
index 6f1dc762fd..de0215727c 100644
--- a/apps/block_scout_web/lib/block_scout_web/templates/address_token_balance/_token_balances.html.eex
+++ b/apps/block_scout_web/lib/block_scout_web/templates/address_token_balance/_token_balances.html.eex
@@ -1,6 +1,6 @@
 <%= if Enum.any?(@token_balances) do %>
-  <a href="#"
-      class="text-white text-faded"
+  <a
+      href="#"
       data-dropdown-toggle
       data-toggle="dropdown"
       role="button"
diff --git a/apps/block_scout_web/lib/block_scout_web/templates/address_token_balance/_tokens.html.eex b/apps/block_scout_web/lib/block_scout_web/templates/address_token_balance/_tokens.html.eex
index 1366a83a0a..13a8b56062 100644
--- a/apps/block_scout_web/lib/block_scout_web/templates/address_token_balance/_tokens.html.eex
+++ b/apps/block_scout_web/lib/block_scout_web/templates/address_token_balance/_tokens.html.eex
@@ -15,7 +15,7 @@
             class: "dropdown-item"
           ) do %>
         <div class="row">
-          <p class="mb-0 col-md-6"><%= token_name(token_balance.token) %></p>
+          <p class="mb-0 col-md-6">xxxxxxxxxxxxx<%= token_name(token_balance.token) %></p>
           <%= if token_balance.token.usd_value do %>
             <p class="mb-0 col-md-6 text-right">
               <span data-selector="token-balance-usd" data-usd-value="<%= balance_in_usd(token_balance) %>"></span>
@@ -23,7 +23,7 @@
           <% end %>
         </div>
         <div class="row">
-          <p class="mb-0 col-md-6">
+          <p class="mb-0 col-md-6">xxxxxxxxxxx
             <%= format_according_to_decimals(token_balance.value, token_balance.token.decimals) %> <%= token_balance.token.symbol %>
           </p>
           <%= if token_balance.token.usd_value do %>

From 74f4e5d269500f41c2e7569498e781df8593ba42 Mon Sep 17 00:00:00 2001
From: Gabriel Rodriguez Alsina <gabriel.rodriguez@altoros.com>
Date: Mon, 13 May 2019 20:54:01 -0300
Subject: [PATCH 2/8] (update) changelog

---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9d4771720c..8e097264da 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,7 @@
 
 ### Fixes
 
+- [#1944](https://github.com/poanetwork/blockscout/pull/1944) - fixed styles for token's dropdown.
 - [#1926](https://github.com/poanetwork/blockscout/pull/1926) - status label alignment
 - [#1829](https://github.com/poanetwork/blockscout/pull/1829) - Handle nil quantities in block decoding routine
 - [#1830](https://github.com/poanetwork/blockscout/pull/1830) - Make block size field nullable

From 833cdb384f86962ad50e25f9e0f45d17233d2b4a Mon Sep 17 00:00:00 2001
From: zachdaniel <zachary.s.daniel@gmail.com>
Date: Tue, 14 May 2019 09:59:14 -0400
Subject: [PATCH 3/8] feat: exclude empty contracts by default

---
 CHANGELOG.md                                  |  1 +
 .../api/rpc/contract_controller.ex            |  5 ++
 .../lib/block_scout_web/etherscan.ex          |  2 +-
 .../api/rpc/contract_controller_test.exs      | 57 +++++++++++++++++++
 apps/explorer/lib/explorer/chain.ex           | 15 +++++
 5 files changed, 79 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0eed85aec8..02a2349bf0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,7 @@
 - [#1920](https://github.com/poanetwork/blockscout/pull/1920) - fix: remove source code fields from list endpoint
 - [#1876](https://github.com/poanetwork/blockscout/pull/1876) - async calculate a count of blocks
 - [#1941](https://github.com/poanetwork/blockscout/pull/1941) - feat: add on demand fetching and stale attr to rpc
+- [#1952](https://github.com/poanetwork/blockscout/pull/1952) - feat: exclude empty contracts by default
 
 ### Fixes
 
diff --git a/apps/block_scout_web/lib/block_scout_web/controllers/api/rpc/contract_controller.ex b/apps/block_scout_web/lib/block_scout_web/controllers/api/rpc/contract_controller.ex
index 886bbcd575..23dacd45da 100644
--- a/apps/block_scout_web/lib/block_scout_web/controllers/api/rpc/contract_controller.ex
+++ b/apps/block_scout_web/lib/block_scout_web/controllers/api/rpc/contract_controller.ex
@@ -103,6 +103,9 @@ defmodule BlockScoutWeb.API.RPC.ContractController do
       :not_decompiled ->
         Chain.list_not_decompiled_contracts(page_size, offset)
 
+      :empty ->
+        Chain.list_empty_contracts(page_size, offset)
+
       _ ->
         Chain.list_contracts(page_size, offset)
     end
@@ -140,10 +143,12 @@ defmodule BlockScoutWeb.API.RPC.ContractController do
   defp contracts_filter(2), do: {:ok, :decompiled}
   defp contracts_filter(3), do: {:ok, :unverified}
   defp contracts_filter(4), do: {:ok, :not_decompiled}
+  defp contracts_filter(5), do: {:ok, :empty}
   defp contracts_filter("verified"), do: {:ok, :verified}
   defp contracts_filter("decompiled"), do: {:ok, :decompiled}
   defp contracts_filter("unverified"), do: {:ok, :unverified}
   defp contracts_filter("not_decompiled"), do: {:ok, :not_decompiled}
+  defp contracts_filter("empty"), do: {:ok, :empty}
 
   defp contracts_filter(filter) when is_bitstring(filter) do
     case Integer.parse(filter) do
diff --git a/apps/block_scout_web/lib/block_scout_web/etherscan.ex b/apps/block_scout_web/lib/block_scout_web/etherscan.ex
index 3621a12d10..a657ff8fd2 100644
--- a/apps/block_scout_web/lib/block_scout_web/etherscan.ex
+++ b/apps/block_scout_web/lib/block_scout_web/etherscan.ex
@@ -1795,7 +1795,7 @@ defmodule BlockScoutWeb.Etherscan do
         key: "filter",
         type: "string",
         description:
-          "verified|decompiled|unverified|not_decompiled, or 1|2|3|4 respectively. This requests only contracts with that status."
+          "verified|decompiled|unverified|not_decompiled|empty, or 1|2|3|4|5 respectively. This requests only contracts with that status."
       },
       %{
         key: "not_decompiled_with_version",
diff --git a/apps/block_scout_web/test/block_scout_web/controllers/api/rpc/contract_controller_test.exs b/apps/block_scout_web/test/block_scout_web/controllers/api/rpc/contract_controller_test.exs
index 43169a65d2..399e49bfff 100644
--- a/apps/block_scout_web/test/block_scout_web/controllers/api/rpc/contract_controller_test.exs
+++ b/apps/block_scout_web/test/block_scout_web/controllers/api/rpc/contract_controller_test.exs
@@ -100,6 +100,34 @@ defmodule BlockScoutWeb.API.RPC.ContractControllerTest do
              ]
     end
 
+    test "filtering for only unverified contracts does not show self destructed contracts", %{
+      params: params,
+      conn: conn
+    } do
+      address = insert(:contract_address)
+      insert(:smart_contract)
+      insert(:contract_address, contract_code: "0x")
+
+      response =
+        conn
+        |> get("/api", Map.put(params, "filter", "unverified"))
+        |> json_response(200)
+
+      assert response["message"] == "OK"
+      assert response["status"] == "1"
+
+      assert response["result"] == [
+               %{
+                 "ABI" => "Contract source code not verified",
+                 "Address" => to_string(address.hash),
+                 "CompilerVersion" => "",
+                 "ContractName" => "",
+                 "DecompilerVersion" => "",
+                 "OptimizationUsed" => ""
+               }
+             ]
+    end
+
     test "filtering for only verified contracts shows only verified contracts", %{params: params, conn: conn} do
       insert(:contract_address)
       contract = insert(:smart_contract)
@@ -222,6 +250,35 @@ defmodule BlockScoutWeb.API.RPC.ContractControllerTest do
                }
              ]
     end
+
+    test "filtering for only not_decompiled (and by extension not verified contracts) does not show empty contracts", %{
+      params: params,
+      conn: conn
+    } do
+      insert(:decompiled_smart_contract)
+      insert(:smart_contract)
+      insert(:contract_address, contract_code: "0x")
+      contract_address = insert(:contract_address)
+
+      response =
+        conn
+        |> get("/api", Map.put(params, "filter", "not_decompiled"))
+        |> json_response(200)
+
+      assert response["message"] == "OK"
+      assert response["status"] == "1"
+
+      assert response["result"] == [
+               %{
+                 "ABI" => "Contract source code not verified",
+                 "Address" => to_string(contract_address.hash),
+                 "CompilerVersion" => "",
+                 "ContractName" => "",
+                 "DecompilerVersion" => "",
+                 "OptimizationUsed" => ""
+               }
+             ]
+    end
   end
 
   describe "getabi" do
diff --git a/apps/explorer/lib/explorer/chain.ex b/apps/explorer/lib/explorer/chain.ex
index 713d449d72..adb9759638 100644
--- a/apps/explorer/lib/explorer/chain.ex
+++ b/apps/explorer/lib/explorer/chain.ex
@@ -2802,6 +2802,7 @@ defmodule Explorer.Chain do
         on: smart_contract.address_hash == address.hash,
         where: not is_nil(address.contract_code),
         where: is_nil(smart_contract.address_hash),
+        where: address.contract_code != <<>>,
         preload: [{:smart_contract, smart_contract}, :decompiled_smart_contracts],
         order_by: [asc: address.inserted_at],
         limit: ^limit,
@@ -2811,6 +2812,19 @@ defmodule Explorer.Chain do
     Repo.all(query)
   end
 
+  def list_empty_contracts(limit, offset) do
+    query =
+      from(address in Address,
+        where: address.contract_code == <<>>,
+        preload: [:smart_contract, :decompiled_smart_contracts],
+        order_by: [asc: address.inserted_at],
+        limit: ^limit,
+        offset: ^offset
+      )
+
+    Repo.all(query)
+  end
+
   def list_not_decompiled_contracts(limit, offset) do
     query =
       from(
@@ -2820,6 +2834,7 @@ defmodule Explorer.Chain do
             "NOT EXISTS (SELECT 1 FROM decompiled_smart_contracts WHERE decompiled_smart_contracts.address_hash = ?)",
             address.hash
           ),
+        where: address.contract_code != <<>>,
         left_join: smart_contract in SmartContract,
         on: smart_contract.address_hash == address.hash,
         left_join: decompiled_smart_contract in DecompiledSmartContract,

From d727ab9728372f15ab51eb5861034153f807a30f Mon Sep 17 00:00:00 2001
From: pasqu4le <pasqu4le@gmail.com>
Date: Thu, 9 May 2019 12:32:02 +0200
Subject: [PATCH 4/8] Test block refetch after transactions overwritten by race
 condition

Regression test for the race condition described in issue #1911
---
 .../chain/import/runner/blocks_test.exs       | 47 ++++++++++++++++++-
 1 file changed, 46 insertions(+), 1 deletion(-)

diff --git a/apps/explorer/test/explorer/chain/import/runner/blocks_test.exs b/apps/explorer/test/explorer/chain/import/runner/blocks_test.exs
index ecf1d71dfb..63110cba40 100644
--- a/apps/explorer/test/explorer/chain/import/runner/blocks_test.exs
+++ b/apps/explorer/test/explorer/chain/import/runner/blocks_test.exs
@@ -6,7 +6,7 @@ defmodule Explorer.Chain.Import.Runner.BlocksTest do
   import Explorer.Chain.Import.RunnerCase, only: [insert_address_with_token_balances: 1, update_holder_count!: 2]
 
   alias Ecto.Multi
-  alias Explorer.Chain.Import.Runner.{Blocks, Transaction}
+  alias Explorer.Chain.Import.Runner.{Blocks, Transactions}
   alias Explorer.Chain.{Address, Block, Transaction}
   alias Explorer.Chain
   alias Explorer.Repo
@@ -283,6 +283,29 @@ defmodule Explorer.Chain.Import.Runner.BlocksTest do
       insert_block(new_block1, options)
       assert Chain.missing_block_number_ranges(range) == []
     end
+
+    # Regression test for https://github.com/poanetwork/blockscout/issues/1911
+    test "forces block refetch if transaction is re-collated in a different block",
+         %{consensus_block: %Block{number: block_number, hash: block_hash, miner_hash: miner_hash}, options: options} do
+      new_block1 = params_for(:block, miner_hash: miner_hash, parent_hash: block_hash, number: block_number + 1)
+      new_block2 = params_for(:block, miner_hash: miner_hash, parent_hash: new_block1.hash, number: block_number + 2)
+
+      range = block_number..(block_number + 2)
+
+      insert_block(new_block1, options)
+      insert_block(new_block2, options)
+      assert Chain.missing_block_number_ranges(range) == []
+
+      trans_hash = transaction_hash()
+
+      transaction1 = transaction_params_with_block([hash: trans_hash], new_block1)
+      insert_transaction(transaction1, options)
+      assert Chain.missing_block_number_ranges(range) == []
+
+      transaction2 = transaction_params_with_block([hash: trans_hash], new_block2)
+      insert_transaction(transaction2, options)
+      assert Chain.missing_block_number_ranges(range) == [(block_number + 1)..(block_number + 1)]
+    end
   end
 
   defp insert_block(block_params, options) do
@@ -293,6 +316,28 @@ defmodule Explorer.Chain.Import.Runner.BlocksTest do
     |> Repo.transaction()
   end
 
+  defp transaction_params_with_block(transaction_params, block_params) do
+    params_for(:transaction, transaction_params)
+    |> Map.merge(%{
+      block_hash: block_params.hash,
+      block_number: block_params.number,
+      cumulative_gas_used: 50_000,
+      error: nil,
+      gas_used: 50_000,
+      index: 0,
+      from_address_hash: insert(:address).hash
+    })
+  end
+
+  defp insert_transaction(transaction_params, options) do
+    %Ecto.Changeset{valid?: true, changes: transaction_changes} =
+      Transaction.changeset(%Transaction{}, transaction_params)
+
+    Multi.new()
+    |> Transactions.run([transaction_changes], options)
+    |> Repo.transaction()
+  end
+
   defp count(schema) do
     Repo.one!(select(schema, fragment("COUNT(*)")))
   end

From e73b7276285b8b6fb9e39786e3e839a351336ad6 Mon Sep 17 00:00:00 2001
From: goodsoft <goodsoft@goodsoft.lv>
Date: Wed, 8 May 2019 18:43:53 +0300
Subject: [PATCH 5/8] Fix potential race condition while dropping replaced
 transactions

Don't discard a transaction if it was eventually collated in the period
between replaced transaction worker initialization and actual dropping.
---
 apps/explorer/lib/explorer/chain.ex | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/apps/explorer/lib/explorer/chain.ex b/apps/explorer/lib/explorer/chain.ex
index adb9759638..59258a90d1 100644
--- a/apps/explorer/lib/explorer/chain.ex
+++ b/apps/explorer/lib/explorer/chain.ex
@@ -2565,7 +2565,7 @@ defmodule Explorer.Chain do
         join: duplicate in subquery(query),
         on: duplicate.nonce == pending.nonce,
         on: duplicate.from_address_hash == pending.from_address_hash,
-        where: pending.hash in ^hashes
+        where: pending.hash in ^hashes and is_nil(pending.block_hash)
       )
 
     Repo.update_all(transactions_to_update, [set: [error: "dropped/replaced", status: :error]], timeout: timeout)

From b9cc8a417fdf22eb6e3d35643fd2eb2aa4237fb9 Mon Sep 17 00:00:00 2001
From: goodsoft <goodsoft@goodsoft.lv>
Date: Wed, 8 May 2019 18:48:09 +0300
Subject: [PATCH 6/8] Force block refetch if transaction is recollated in a
 different block

Due to race conditions described in #1911 transactions from a consensus
block might get overwritten by the same transactions from a non-consensus
block.

To prevent this we force a block refetch (by marking it as non-consensus),
if a transaction belonging to it gets overwritten by the same transaction
from a different block.
---
 .../chain/import/runner/transactions.ex       | 50 +++++++++++++++++--
 .../lib/explorer/chain/transaction.ex         |  5 ++
 ...22_add_old_block_hash_for_transactions.exs | 12 +++++
 3 files changed, 64 insertions(+), 3 deletions(-)
 create mode 100644 apps/explorer/priv/repo/migrations/20190508152922_add_old_block_hash_for_transactions.exs

diff --git a/apps/explorer/lib/explorer/chain/import/runner/transactions.ex b/apps/explorer/lib/explorer/chain/import/runner/transactions.ex
index 4f1d2d6fe5..1a9fcc497d 100644
--- a/apps/explorer/lib/explorer/chain/import/runner/transactions.ex
+++ b/apps/explorer/lib/explorer/chain/import/runner/transactions.ex
@@ -8,7 +8,7 @@ defmodule Explorer.Chain.Import.Runner.Transactions do
   import Ecto.Query, only: [from: 2]
 
   alias Ecto.{Multi, Repo}
-  alias Explorer.Chain.{Data, Hash, Import, Transaction}
+  alias Explorer.Chain.{Block, Data, Hash, Import, Transaction}
   alias Explorer.Chain.Import.Runner.TokenTransfers
 
   @behaviour Import.Runner
@@ -42,9 +42,13 @@ defmodule Explorer.Chain.Import.Runner.Transactions do
       |> Map.put(:timestamps, timestamps)
       |> Map.put(:token_transfer_transaction_hash_set, token_transfer_transaction_hash_set(options))
 
-    Multi.run(multi, :transactions, fn repo, _ ->
+    multi
+    |> Multi.run(:transactions, fn repo, _ ->
       insert(repo, changes_list, insert_options)
     end)
+    |> Multi.run(:recollated_transactions, fn repo, %{transactions: transactions} ->
+      discard_blocks_for_recollated_transactions(repo, transactions, insert_options)
+    end)
   end
 
   @impl Import.Runner
@@ -87,7 +91,7 @@ defmodule Explorer.Chain.Import.Runner.Transactions do
       on_conflict: on_conflict,
       for: Transaction,
       returning:
-        ~w(block_number index hash internal_transactions_indexed_at block_hash nonce from_address_hash created_contract_address_hash)a,
+        ~w(block_number index hash internal_transactions_indexed_at block_hash old_block_hash nonce from_address_hash created_contract_address_hash)a,
       timeout: timeout,
       timestamps: timestamps
     )
@@ -99,6 +103,7 @@ defmodule Explorer.Chain.Import.Runner.Transactions do
       update: [
         set: [
           block_hash: fragment("EXCLUDED.block_hash"),
+          old_block_hash: transaction.block_hash,
           block_number: fragment("EXCLUDED.block_number"),
           created_contract_address_hash: fragment("EXCLUDED.created_contract_address_hash"),
           cumulative_gas_used: fragment("EXCLUDED.cumulative_gas_used"),
@@ -179,4 +184,43 @@ defmodule Explorer.Chain.Import.Runner.Transactions do
   end
 
   defp put_internal_transactions_indexed_at?(_, _), do: false
+
+  defp discard_blocks_for_recollated_transactions(repo, transactions, %{
+         timeout: timeout,
+         timestamps: %{updated_at: updated_at}
+       })
+       when is_list(transactions) do
+    ordered_block_hashes =
+      transactions
+      |> Enum.filter(fn %{block_hash: block_hash, old_block_hash: old_block_hash} ->
+        not is_nil(old_block_hash) and block_hash != old_block_hash
+      end)
+      |> MapSet.new(& &1.old_block_hash)
+      |> Enum.sort()
+
+    if Enum.empty?(ordered_block_hashes) do
+      {:ok, []}
+    else
+      query =
+        from(
+          block in Block,
+          where: block.hash in ^ordered_block_hashes,
+          update: [
+            set: [
+              consensus: false,
+              updated_at: ^updated_at
+            ]
+          ]
+        )
+
+      try do
+        {_, result} = repo.update_all(query, [], timeout: timeout)
+
+        {:ok, result}
+      rescue
+        postgrex_error in Postgrex.Error ->
+          {:error, %{exception: postgrex_error, block_hashes: ordered_block_hashes}}
+      end
+    end
+  end
 end
diff --git a/apps/explorer/lib/explorer/chain/transaction.ex b/apps/explorer/lib/explorer/chain/transaction.ex
index 1cf9c8f116..de99198181 100644
--- a/apps/explorer/lib/explorer/chain/transaction.ex
+++ b/apps/explorer/lib/explorer/chain/transaction.ex
@@ -205,6 +205,11 @@ defmodule Explorer.Chain.Transaction do
     field(:v, :decimal)
     field(:value, Wei)
 
+    # A transient field for deriving old block hash during transaction upserts.
+    # Used to force refetch of a block in case a transaction is re-collated
+    # in a different block. See: https://github.com/poanetwork/blockscout/issues/1911
+    field(:old_block_hash, Hash.Full)
+
     timestamps()
 
     belongs_to(:block, Block, foreign_key: :block_hash, references: :hash, type: Hash.Full)
diff --git a/apps/explorer/priv/repo/migrations/20190508152922_add_old_block_hash_for_transactions.exs b/apps/explorer/priv/repo/migrations/20190508152922_add_old_block_hash_for_transactions.exs
new file mode 100644
index 0000000000..daf04c22f3
--- /dev/null
+++ b/apps/explorer/priv/repo/migrations/20190508152922_add_old_block_hash_for_transactions.exs
@@ -0,0 +1,12 @@
+defmodule Explorer.Repo.Migrations.AddOldBlockHashForTransactions do
+  use Ecto.Migration
+
+  def change do
+    alter table(:transactions) do
+      # A transient field for deriving old block hash during transaction upserts.
+      # Used to force refetch of a block in case a transaction is re-collated
+      # in a different block. See: https://github.com/poanetwork/blockscout/issues/1911
+      add(:old_block_hash, :bytea, null: true)
+    end
+  end
+end

From 64acef7b7106ab008355fe649ef348211e4c9231 Mon Sep 17 00:00:00 2001
From: pasqu4le <pasqu4le@gmail.com>
Date: Fri, 10 May 2019 19:52:22 +0200
Subject: [PATCH 7/8] Add temporary indexer worker to remove consensus on
 blocks with mismatching transactions

After the solution for #1991 it is necessary to remove consensus from blocks whose number of transactions mismatch compared to a node, so that these blocks are refetched.
---
 CHANGELOG.md                                  |   1 +
 apps/explorer/lib/explorer/chain/block.ex     |   6 +-
 ...0513134025_add_refetch_needed_to_block.exs |  11 ++
 apps/indexer/README.md                        |   1 +
 apps/indexer/lib/indexer/supervisor.ex        |   3 +
 .../temporary/blocks_transactions_mismatch.ex | 115 ++++++++++++++++++
 6 files changed, 135 insertions(+), 2 deletions(-)
 create mode 100644 apps/explorer/priv/repo/migrations/20190513134025_add_refetch_needed_to_block.exs
 create mode 100644 apps/indexer/lib/indexer/temporary/blocks_transactions_mismatch.ex

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0a7159ec7d..22cca8a536 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -43,6 +43,7 @@
 - [#1898](https://github.com/poanetwork/blockscout/pull/1898) - check if the constructor has arguments before verifying constructor arguments
 - [#1915](https://github.com/poanetwork/blockscout/pull/1915) - fallback to 2 latest evm versions
 - [#1937](https://github.com/poanetwork/blockscout/pull/1937) - Check the presence of overlap[i] object before retrieving properties from it
+- [#1917](https://github.com/poanetwork/blockscout/pull/1917) - Force block refetch if transaction is re-collated in a different block
 
 ### Chore
 
diff --git a/apps/explorer/lib/explorer/chain/block.ex b/apps/explorer/lib/explorer/chain/block.ex
index 58d187d9d8..9cf86b570b 100644
--- a/apps/explorer/lib/explorer/chain/block.ex
+++ b/apps/explorer/lib/explorer/chain/block.ex
@@ -10,7 +10,7 @@ defmodule Explorer.Chain.Block do
   alias Explorer.Chain.{Address, Gas, Hash, Transaction}
   alias Explorer.Chain.Block.{Reward, SecondDegreeRelation}
 
-  @optional_attrs ~w(internal_transactions_indexed_at size)a
+  @optional_attrs ~w(internal_transactions_indexed_at size refetch_needed)a
 
   @required_attrs ~w(consensus difficulty gas_limit gas_used hash miner_hash nonce number parent_hash timestamp total_difficulty)a
 
@@ -63,7 +63,8 @@ defmodule Explorer.Chain.Block do
           timestamp: DateTime.t(),
           total_difficulty: difficulty(),
           transactions: %Ecto.Association.NotLoaded{} | [Transaction.t()],
-          internal_transactions_indexed_at: DateTime.t()
+          internal_transactions_indexed_at: DateTime.t(),
+          refetch_needed: boolean()
         }
 
   @primary_key {:hash, Hash.Full, autogenerate: false}
@@ -78,6 +79,7 @@ defmodule Explorer.Chain.Block do
     field(:timestamp, :utc_datetime_usec)
     field(:total_difficulty, :decimal)
     field(:internal_transactions_indexed_at, :utc_datetime_usec)
+    field(:refetch_needed, :boolean)
 
     timestamps()
 
diff --git a/apps/explorer/priv/repo/migrations/20190513134025_add_refetch_needed_to_block.exs b/apps/explorer/priv/repo/migrations/20190513134025_add_refetch_needed_to_block.exs
new file mode 100644
index 0000000000..70ddac3e03
--- /dev/null
+++ b/apps/explorer/priv/repo/migrations/20190513134025_add_refetch_needed_to_block.exs
@@ -0,0 +1,11 @@
+defmodule Explorer.Repo.Migrations.AddRefetchNeededToBlock do
+  use Ecto.Migration
+
+  def change do
+    alter table(:blocks) do
+      add(:refetch_needed, :boolean, default: false)
+    end
+
+    execute("UPDATE blocks SET refetch_needed = TRUE;", "")
+  end
+end
diff --git a/apps/indexer/README.md b/apps/indexer/README.md
index 34fb6e6ef3..173df0c6ab 100644
--- a/apps/indexer/README.md
+++ b/apps/indexer/README.md
@@ -92,6 +92,7 @@ After all deployed instances get all needed data, these fetchers should be depre
 
 - `uncataloged_token_transfers`: extracts token transfers from logs, which previously weren't parsed due to unknown format
 - `uncles_without_index`: adds previously unfetched `index` field for unfetched blocks in `block_second_degree_relations`
+- `blocks_transactions_mismatch`: refetches each block once and revokes consensus to those whose transaction number mismatches with the number currently stored. This is meant to force the correction of a race condition that caused successfully fetched transactions to be overwritten by a following non-consensus block: [#1911](https://github.com/poanetwork/blockscout/issues/1911).
 
 ## Memory Usage
 
diff --git a/apps/indexer/lib/indexer/supervisor.ex b/apps/indexer/lib/indexer/supervisor.ex
index 21dc3637ec..b2c3d19664 100644
--- a/apps/indexer/lib/indexer/supervisor.ex
+++ b/apps/indexer/lib/indexer/supervisor.ex
@@ -24,6 +24,7 @@ defmodule Indexer.Supervisor do
   }
 
   alias Indexer.Temporary.{
+    BlocksTransactionsMismatch,
     UncatalogedTokenTransfers,
     UnclesWithoutIndex
   }
@@ -124,6 +125,8 @@ defmodule Indexer.Supervisor do
         # Temporary workers
         {UncatalogedTokenTransfers.Supervisor, [[]]},
         {UnclesWithoutIndex.Supervisor,
+         [[json_rpc_named_arguments: json_rpc_named_arguments, memory_monitor: memory_monitor]]},
+        {BlocksTransactionsMismatch.Supervisor,
          [[json_rpc_named_arguments: json_rpc_named_arguments, memory_monitor: memory_monitor]]}
       ],
       strategy: :one_for_one
diff --git a/apps/indexer/lib/indexer/temporary/blocks_transactions_mismatch.ex b/apps/indexer/lib/indexer/temporary/blocks_transactions_mismatch.ex
new file mode 100644
index 0000000000..76f4322379
--- /dev/null
+++ b/apps/indexer/lib/indexer/temporary/blocks_transactions_mismatch.ex
@@ -0,0 +1,115 @@
+defmodule Indexer.Temporary.BlocksTransactionsMismatch do
+  @moduledoc """
+  Fetches `consensus` `t:Explorer.Chain.Block.t/0` and compares their transaction
+  number against a node, to revoke `consensus` on mismatch.
+
+  This is meant to fix incorrectly strored transactions that happened as a result
+  of a race condition due to the asynchronicity of indexer's components.
+  """
+
+  use Indexer.Fetcher
+
+  require Logger
+
+  import Ecto.Query
+
+  alias Ecto.Multi
+  alias EthereumJSONRPC.Blocks
+  alias Explorer.Chain.Block
+  alias Explorer.Repo
+  alias Indexer.BufferedTask
+
+  @behaviour BufferedTask
+
+  @defaults [
+    flush_interval: :timer.seconds(3),
+    max_batch_size: 10,
+    max_concurrency: 4,
+    task_supervisor: Indexer.Temporary.BlocksTransactionsMismatch.TaskSupervisor,
+    metadata: [fetcher: :blocks_transactions_mismatch]
+  ]
+
+  @doc false
+  def child_spec([init_options, gen_server_options]) when is_list(init_options) do
+    {state, mergeable_init_options} = Keyword.pop(init_options, :json_rpc_named_arguments)
+
+    unless state do
+      raise ArgumentError,
+            ":json_rpc_named_arguments must be provided to `#{__MODULE__}.child_spec " <>
+              "to allow for json_rpc calls when running."
+    end
+
+    merged_init_options =
+      @defaults
+      |> Keyword.merge(mergeable_init_options)
+      |> Keyword.put(:state, state)
+
+    Supervisor.child_spec({BufferedTask, [{__MODULE__, merged_init_options}, gen_server_options]}, id: __MODULE__)
+  end
+
+  @impl BufferedTask
+  def init(initial, reducer, _) do
+    query =
+      from(block in Block,
+        join: transactions in assoc(block, :transactions),
+        where: block.consensus and block.refetch_needed,
+        group_by: block.hash,
+        select: {block, count(transactions.hash)}
+      )
+
+    {:ok, final} = Repo.stream_reduce(query, initial, &reducer.(&1, &2))
+
+    final
+  end
+
+  @impl BufferedTask
+  def run(blocks_data, json_rpc_named_arguments) do
+    hashes = Enum.map(blocks_data, fn {block, _trans_num} -> block.hash end)
+
+    Logger.debug("fetching")
+
+    case EthereumJSONRPC.fetch_blocks_by_hash(hashes, json_rpc_named_arguments) do
+      {:ok, blocks} ->
+        run_blocks(blocks, blocks_data)
+
+      {:error, reason} ->
+        Logger.error(fn -> ["failed to fetch: ", inspect(reason)] end)
+        {:retry, blocks_data}
+    end
+  end
+
+  defp run_blocks(%Blocks{blocks_params: []}, blocks_data), do: {:retry, blocks_data}
+
+  defp run_blocks(
+         %Blocks{transactions_params: transactions_params},
+         blocks_data
+       ) do
+    found_blocks_map =
+      transactions_params
+      |> Enum.group_by(&Map.fetch!(&1, :block_hash))
+      |> Map.new(fn {block_hash, trans_lst} -> {block_hash, Enum.count(trans_lst)} end)
+
+    {found_blocks_data, missing_blocks_data} =
+      Enum.split_with(blocks_data, fn {block, _trans_num} ->
+        Map.has_key?(found_blocks_map, to_string(block.hash))
+      end)
+
+    {:ok, _} =
+      found_blocks_data
+      |> Enum.reduce(Multi.new(), fn {block, trans_num}, multi ->
+        changes = %{
+          refetch_needed: false,
+          consensus: found_blocks_map[to_string(block.hash)] == trans_num
+        }
+
+        Multi.update(multi, block.hash, Block.changeset(block, changes))
+      end)
+      |> Repo.transaction()
+
+    if Enum.empty?(missing_blocks_data) do
+      :ok
+    else
+      {:retry, missing_blocks_data}
+    end
+  end
+end

From 750a665fe6ef35ac44e35e90d61c3ce353f6776b Mon Sep 17 00:00:00 2001
From: Gabriel Rodriguez Alsina <gabriel.rodriguez@altoros.com>
Date: Wed, 15 May 2019 12:10:28 -0300
Subject: [PATCH 8/8] (fix) remove text

---
 .../templates/address_token_balance/_tokens.html.eex          | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/apps/block_scout_web/lib/block_scout_web/templates/address_token_balance/_tokens.html.eex b/apps/block_scout_web/lib/block_scout_web/templates/address_token_balance/_tokens.html.eex
index 13a8b56062..1366a83a0a 100644
--- a/apps/block_scout_web/lib/block_scout_web/templates/address_token_balance/_tokens.html.eex
+++ b/apps/block_scout_web/lib/block_scout_web/templates/address_token_balance/_tokens.html.eex
@@ -15,7 +15,7 @@
             class: "dropdown-item"
           ) do %>
         <div class="row">
-          <p class="mb-0 col-md-6">xxxxxxxxxxxxx<%= token_name(token_balance.token) %></p>
+          <p class="mb-0 col-md-6"><%= token_name(token_balance.token) %></p>
           <%= if token_balance.token.usd_value do %>
             <p class="mb-0 col-md-6 text-right">
               <span data-selector="token-balance-usd" data-usd-value="<%= balance_in_usd(token_balance) %>"></span>
@@ -23,7 +23,7 @@
           <% end %>
         </div>
         <div class="row">
-          <p class="mb-0 col-md-6">xxxxxxxxxxx
+          <p class="mb-0 col-md-6">
             <%= format_according_to_decimals(token_balance.value, token_balance.token.decimals) %> <%= token_balance.token.symbol %>
           </p>
           <%= if token_balance.token.usd_value do %>