Merge pull request #4993 from blockscout/vb-fix-address_to_gas_usage_count

address_to_gas_usage_count function fix for nil incoming transactions gas usage count

CHANGELOG.md

@@ -5,7 +5,7 @@
 - [#4931](https://github.com/blockscout/blockscout/pull/4931) - Web3 modal with Wallet Connect for Write contract page and Staking Dapp
 
 ### Fixes
-- [#4979](https://github.com/blockscout/blockscout/pull/4979) - Store total gas_used in addresses table
+- [#4979](https://github.com/blockscout/blockscout/pull/4979), [#4993](https://github.com/blockscout/blockscout/pull/4993) - Store total gas_used in addresses table
 - [#4977](https://github.com/blockscout/blockscout/pull/4977) - Export token transfers on address: include transfers on contract itself
 - [#4976](https://github.com/blockscout/blockscout/pull/4976) - Handle :econnrefused in pending transactions fetcher
 - [#4965](https://github.com/blockscout/blockscout/pull/4965) - Fix search field appearance on medium size screens

apps/explorer/lib/explorer/chain.ex

@@ -2548,10 +2548,15 @@ defmodule Explorer.Chain do
     if contract?(address) do
       incoming_transaction_gas_usage = address_to_incoming_transaction_gas_usage(address.hash)
 
-      if Decimal.cmp(incoming_transaction_gas_usage, 0) == :eq do
-        address_to_outcoming_transaction_gas_usage(address.hash)
-      else
-        incoming_transaction_gas_usage
+      cond do
+        !incoming_transaction_gas_usage ->
+          address_to_outcoming_transaction_gas_usage(address.hash)
+
+        Decimal.cmp(incoming_transaction_gas_usage, 0) == :eq ->
+          address_to_outcoming_transaction_gas_usage(address.hash)
+
+        true ->
+          incoming_transaction_gas_usage
       end
     else
       address_to_outcoming_transaction_gas_usage(address.hash)