From 7df9ebd316e7175683861667b787519d450c40a6 Mon Sep 17 00:00:00 2001
From: "mergify[bot]" <37929162+mergify[bot]@users.noreply.github.com>
Date: Tue, 8 Oct 2024 11:02:36 +0200
Subject: [PATCH] fix: avoid invalid identifier error when validate genesis
 (backport #7397) (#7403)
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* fix: avoid invalid identifier error when validate genesis (#7397)

* fix: avoid invalid identifier error when validate genesis

that contains localhost client

* Apply suggestions from code review

* skip

(cherry picked from commit ff2b668cfd270dc15ab698667ca1442fc590eab4)

# Conflicts:
#	CHANGELOG.md
#	modules/core/03-connection/types/genesis.go
#	modules/core/03-connection/types/genesis_test.go

* chore: changelog cleanup

* chore: fix imports

---------

Co-authored-by: mmsqe <mavis@crypto.com>
Co-authored-by: Colin Axnér <25233464+colin-axner@users.noreply.github.com>
---
 CHANGELOG.md                                     |  2 ++
 modules/core/03-connection/types/genesis.go      | 16 +++++++++-------
 modules/core/03-connection/types/genesis_test.go | 15 +++++++++++++++
 3 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 200cd0fbb55..e2518d7e85d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -48,6 +48,8 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Bug Fixes
 
+* (core/03-connection) [\#7397](https://github.com/cosmos/ibc-go/pull/7397) Skip the genesis validation connectionID for localhost client.
+
 ## [v8.5.1](https://github.com/cosmos/ibc-go/releases/tag/v8.5.1) - 2024-09-13
 
 ### Bug Fixes
diff --git a/modules/core/03-connection/types/genesis.go b/modules/core/03-connection/types/genesis.go
index c273f82e363..8536c08ea19 100644
--- a/modules/core/03-connection/types/genesis.go
+++ b/modules/core/03-connection/types/genesis.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 
 	host "github.com/cosmos/ibc-go/v8/modules/core/24-host"
+	"github.com/cosmos/ibc-go/v8/modules/core/exported"
 )
 
 // NewConnectionPaths creates a ConnectionPaths instance.
@@ -45,13 +46,14 @@ func (gs GenesisState) Validate() error {
 	var maxSequence uint64
 
 	for i, conn := range gs.Connections {
-		sequence, err := ParseConnectionSequence(conn.Id)
-		if err != nil {
-			return err
-		}
-
-		if sequence > maxSequence {
-			maxSequence = sequence
+		if conn.Id != exported.LocalhostConnectionID {
+			sequence, err := ParseConnectionSequence(conn.Id)
+			if err != nil {
+				return err
+			}
+			if sequence > maxSequence {
+				maxSequence = sequence
+			}
 		}
 
 		if err := conn.ValidateBasic(); err != nil {
diff --git a/modules/core/03-connection/types/genesis_test.go b/modules/core/03-connection/types/genesis_test.go
index 6e5a0ce1170..b61dc97f892 100644
--- a/modules/core/03-connection/types/genesis_test.go
+++ b/modules/core/03-connection/types/genesis_test.go
@@ -7,6 +7,7 @@ import (
 
 	"github.com/cosmos/ibc-go/v8/modules/core/03-connection/types"
 	commitmenttypes "github.com/cosmos/ibc-go/v8/modules/core/23-commitment/types"
+	"github.com/cosmos/ibc-go/v8/modules/core/exported"
 	ibctesting "github.com/cosmos/ibc-go/v8/testing"
 )
 
@@ -91,6 +92,20 @@ func TestValidateGenesis(t *testing.T) {
 			),
 			expPass: false,
 		},
+		{
+			name: "localhost connection identifier",
+			genState: types.NewGenesisState(
+				[]types.IdentifiedConnection{
+					types.NewIdentifiedConnection(exported.LocalhostConnectionID, types.NewConnectionEnd(types.INIT, clientID, types.Counterparty{clientID2, connectionID2, commitmenttypes.NewMerklePrefix([]byte("prefix"))}, []*types.Version{ibctesting.ConnectionVersion}, 500)),
+				},
+				[]types.ConnectionPaths{
+					{clientID, []string{connectionID}},
+				},
+				0,
+				types.DefaultParams(),
+			),
+			expPass: true,
+		},
 		{
 			name: "next connection sequence is not greater than maximum connection identifier sequence provided",
 			genState: types.NewGenesisState(