From 994815e36c94b45109e7306bfc6da2d7bfee21b2 Mon Sep 17 00:00:00 2001
From: Daniel Wedul <github@wedul.com>
Date: Fri, 13 Oct 2023 15:44:01 -0600
Subject: [PATCH] [1658]: In IndexedAddrAmts.Add, if the coins to add is zero,
 don't do anything.

---
 x/exchange/fulfillment.go      |  3 ++
 x/exchange/fulfillment_test.go | 69 ++++++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+)

diff --git a/x/exchange/fulfillment.go b/x/exchange/fulfillment.go
index 36a6b2fdd3..3d4ad50f1e 100644
--- a/x/exchange/fulfillment.go
+++ b/x/exchange/fulfillment.go
@@ -103,6 +103,9 @@ func NewIndexedAddrAmts() *IndexedAddrAmts {
 // Add adds the coins to the given address.
 // Panics if a provided coin is invalid.
 func (i *IndexedAddrAmts) Add(addr string, coins ...sdk.Coin) {
+	if sdk.Coins(coins).IsZero() {
+		return
+	}
 	for _, coin := range coins {
 		if err := coin.Validate(); err != nil {
 			panic(fmt.Errorf("cannot index and add invalid coin amount %q", coin))
diff --git a/x/exchange/fulfillment_test.go b/x/exchange/fulfillment_test.go
index 61402f0b0f..23a0777ac4 100644
--- a/x/exchange/fulfillment_test.go
+++ b/x/exchange/fulfillment_test.go
@@ -1046,6 +1046,45 @@ func TestIndexedAddrAmts_Add(t *testing.T) {
 		expected *IndexedAddrAmts
 		expPanic string
 	}{
+		{
+			name:     "empty, add zero coins",
+			receiver: NewIndexedAddrAmts(),
+			addr:     "addr1",
+			coins:    nil,
+			expected: NewIndexedAddrAmts(),
+		},
+		{
+			name:     "empty, add one coin with a zero value",
+			receiver: NewIndexedAddrAmts(),
+			addr:     "addr1",
+			coins:    []sdk.Coin{{Denom: "zero", Amount: sdkmath.ZeroInt()}},
+			expected: NewIndexedAddrAmts(),
+		},
+		{
+			name:     "empty, add two coins with a zero value.",
+			receiver: NewIndexedAddrAmts(),
+			addr:     "addr1",
+			coins: []sdk.Coin{
+				{Denom: "zeroa", Amount: sdkmath.ZeroInt()},
+				{Denom: "zerob", Amount: sdkmath.ZeroInt()},
+			},
+			expected: NewIndexedAddrAmts(),
+		},
+		{
+			name:     "empty, add three coins, only one is not zero",
+			receiver: NewIndexedAddrAmts(),
+			addr:     "addr1",
+			coins: []sdk.Coin{
+				{Denom: "coina", Amount: sdkmath.ZeroInt()},
+				{Denom: "coinb", Amount: sdkmath.OneInt()},
+				{Denom: "coinc", Amount: sdkmath.ZeroInt()},
+			},
+			expected: &IndexedAddrAmts{
+				addrs:   []string{"addr1"},
+				amts:    []sdk.Coins{coins("1coinb")},
+				indexes: map[string]int{"addr1": 0},
+			},
+		},
 		{
 			name:     "empty, add one coin",
 			receiver: NewIndexedAddrAmts(),
@@ -1254,6 +1293,36 @@ func TestIndexedAddrAmts_Add(t *testing.T) {
 			coins:    negCoins,
 			expPanic: "cannot index and add invalid coin amount \"-1neg\"",
 		},
+		{
+			name: "three addrs, add zero to existing",
+			receiver: &IndexedAddrAmts{
+				addrs:   []string{"addr1", "addr2", "addr3"},
+				amts:    []sdk.Coins{coins("1one"), coins("2two"), coins("3three")},
+				indexes: map[string]int{"addr1": 0, "addr2": 1, "addr3": 2},
+			},
+			addr:  "addr2",
+			coins: []sdk.Coin{{Denom: "zero", Amount: sdkmath.ZeroInt()}},
+			expected: &IndexedAddrAmts{
+				addrs:   []string{"addr1", "addr2", "addr3"},
+				amts:    []sdk.Coins{coins("1one"), coins("2two"), coins("3three")},
+				indexes: map[string]int{"addr1": 0, "addr2": 1, "addr3": 2},
+			},
+		},
+		{
+			name: "three addrs, add zero to new",
+			receiver: &IndexedAddrAmts{
+				addrs:   []string{"addr1", "addr2", "addr3"},
+				amts:    []sdk.Coins{coins("1one"), coins("2two"), coins("3three")},
+				indexes: map[string]int{"addr1": 0, "addr2": 1, "addr3": 2},
+			},
+			addr:  "addr4",
+			coins: []sdk.Coin{{Denom: "zero", Amount: sdkmath.ZeroInt()}},
+			expected: &IndexedAddrAmts{
+				addrs:   []string{"addr1", "addr2", "addr3"},
+				amts:    []sdk.Coins{coins("1one"), coins("2two"), coins("3three")},
+				indexes: map[string]int{"addr1": 0, "addr2": 1, "addr3": 2},
+			},
+		},
 	}
 
 	for _, tc := range tests {