From 550ccfb58fb5657488f26ecc027f4b3a9a43a91c Mon Sep 17 00:00:00 2001
From: Brian Luk <brian6.dev@gmail.com>
Date: Thu, 18 Dec 2025 13:03:21 -0800
Subject: [PATCH 1/2] Prevent duplicate addresses in platform validators

Add validation to reject duplicate addresses when setting platform
validators. This prevents configuration errors where the same address
could appear multiple times in the list.
---
 x/billing/types/params.go      |  5 ++
 x/billing/types/params_test.go | 85 ++++++++++++++++++++++++++++++++++
 2 files changed, 90 insertions(+)
 create mode 100644 x/billing/types/params_test.go

diff --git a/x/billing/types/params.go b/x/billing/types/params.go
index a35792d..a453963 100644
--- a/x/billing/types/params.go
+++ b/x/billing/types/params.go
@@ -66,11 +66,16 @@ func validatePlatformValidatorsParam(v interface{}) error {
 	if !ok {
 		return fmt.Errorf("could not unmarshal platform-validators parm for validation")
 	}
+	seen := make(map[string]bool)
 	for _, val := range vals {
 		_, err := sdk.AccAddressFromBech32(val)
 		if err != nil {
 			return fmt.Errorf("invalid platform validator address: %s", val)
 		}
+		if seen[val] {
+			return fmt.Errorf("duplicate platform validator address: %s", val)
+		}
+		seen[val] = true
 	}
 	return nil
 }
diff --git a/x/billing/types/params_test.go b/x/billing/types/params_test.go
new file mode 100644
index 0000000..9248e43
--- /dev/null
+++ b/x/billing/types/params_test.go
@@ -0,0 +1,85 @@
+package types
+
+import (
+	"testing"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/stretchr/testify/require"
+)
+
+func init() {
+	config := sdk.GetConfig()
+	config.SetBech32PrefixForAccount("saga", "sagapub")
+	config.SetBech32PrefixForValidator("sagavaloper", "sagavaloperpub")
+	config.SetBech32PrefixForConsensusNode("sagavalcons", "sagavalconspub")
+}
+
+func TestValidatePlatformValidatorsParam(t *testing.T) {
+	addr1 := "saga14grgksm5pe5u4cf8pvcchfsl8mfg8mvj3c95l0"
+	addr2 := "saga1nkm3et2qcqgya0ad8wt6e20l6206xdtccw28c9"
+	addr3 := "saga1zggrvdnjzsfpc7sr7jnw2jl5v9u8vjn263x0s0"
+
+	tests := []struct {
+		name    string
+		input   interface{}
+		wantErr bool
+		errMsg  string
+	}{
+		{
+			name:    "valid empty list",
+			input:   []string{},
+			wantErr: false,
+		},
+		{
+			name:    "valid single address",
+			input:   []string{addr1},
+			wantErr: false,
+		},
+		{
+			name:    "valid multiple addresses",
+			input:   []string{addr1, addr2},
+			wantErr: false,
+		},
+		{
+			name:    "invalid address format",
+			input:   []string{"invalid-address"},
+			wantErr: true,
+			errMsg:  "invalid platform validator address",
+		},
+		{
+			name:    "duplicate addresses",
+			input:   []string{addr1, addr1},
+			wantErr: true,
+			errMsg:  "duplicate platform validator address",
+		},
+		{
+			name:    "duplicate addresses with valid in between",
+			input:   []string{addr1, addr2, addr1},
+			wantErr: true,
+			errMsg:  "duplicate platform validator address",
+		},
+		{
+			name:    "three unique addresses",
+			input:   []string{addr1, addr2, addr3},
+			wantErr: false,
+		},
+		{
+			name:    "wrong type",
+			input:   "not a slice",
+			wantErr: true,
+			errMsg:  "could not unmarshal platform-validators",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := validatePlatformValidatorsParam(tt.input)
+			if tt.wantErr {
+				require.Error(t, err)
+				require.Contains(t, err.Error(), tt.errMsg)
+			} else {
+				require.NoError(t, err)
+			}
+		})
+	}
+}

From 8ee4b11128a40c0bc013f0c30aae0f13a7ce4cce Mon Sep 17 00:00:00 2001
From: Brian Luk <brian6.dev@gmail.com>
Date: Thu, 18 Dec 2025 13:10:54 -0800
Subject: [PATCH 2/2] Add validation to SetPlatformValidators keeper function

Export ValidatePlatformValidators function and call it from the keeper's
SetPlatformValidators method to validate input before storing.
---
 x/billing/keeper/keeper.go | 3 +++
 x/billing/types/params.go  | 6 ++++++
 2 files changed, 9 insertions(+)

diff --git a/x/billing/keeper/keeper.go b/x/billing/keeper/keeper.go
index d637323..e7b188d 100644
--- a/x/billing/keeper/keeper.go
+++ b/x/billing/keeper/keeper.go
@@ -76,6 +76,9 @@ func (k Keeper) GetAuthority() string {
 }
 
 func (k Keeper) SetPlatformValidators(ctx sdk.Context, vals []string) error {
+	if err := types.ValidatePlatformValidators(vals); err != nil {
+		return err
+	}
 	params := k.GetParams(ctx)
 	params.PlatformValidators = vals
 	k.SetParams(ctx, params)
diff --git a/x/billing/types/params.go b/x/billing/types/params.go
index a453963..4fd1304 100644
--- a/x/billing/types/params.go
+++ b/x/billing/types/params.go
@@ -66,6 +66,12 @@ func validatePlatformValidatorsParam(v interface{}) error {
 	if !ok {
 		return fmt.Errorf("could not unmarshal platform-validators parm for validation")
 	}
+	return ValidatePlatformValidators(vals)
+}
+
+// ValidatePlatformValidators validates that all platform validator addresses are valid
+// and that there are no duplicates.
+func ValidatePlatformValidators(vals []string) error {
 	seen := make(map[string]bool)
 	for _, val := range vals {
 		_, err := sdk.AccAddressFromBech32(val)