From fd45567f06b9da7c0199ed026e03da01d3e109e1 Mon Sep 17 00:00:00 2001
From: wwestgarth <william@vega.xyz>
Date: Mon, 2 Sep 2024 17:01:12 +0100
Subject: [PATCH] fix: prevent overflow when calculating tradable volume
 outside of sided range

---
 core/execution/amm/pool.go      |  6 ++++++
 core/execution/amm/pool_test.go | 16 ++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/core/execution/amm/pool.go b/core/execution/amm/pool.go
index e4c89e673e..70a754f684 100644
--- a/core/execution/amm/pool.go
+++ b/core/execution/amm/pool.go
@@ -629,11 +629,17 @@ func (p *Pool) TradableVolumeInRange(side types.Side, price1 *num.Uint, price2 *
 
 	if side == types.SideSell {
 		// want all buy volume so everything below fair price, where the AMM is long
+		if pos > stP {
+			return 0
+		}
 		ndP = num.MaxV(pos, ndP)
 	}
 
 	if side == types.SideBuy {
 		// want all sell volume so everything above fair price, where the AMM is short
+		if pos < ndP {
+			return 0
+		}
 		stP = num.MinV(pos, stP)
 	}
 
diff --git a/core/execution/amm/pool_test.go b/core/execution/amm/pool_test.go
index 0444f469e8..a46d83876d 100644
--- a/core/execution/amm/pool_test.go
+++ b/core/execution/amm/pool_test.go
@@ -113,6 +113,22 @@ func testTradeableVolumeInRange(t *testing.T) {
 			expectedVolume: 1052,
 			position:       -350,
 		},
+		{
+			name:           "AMM is long and price range is fully in short section",
+			price1:         num.NewUint(1900),
+			price2:         num.NewUint(2200),
+			side:           types.SideSell,
+			expectedVolume: 0,
+			position:       700,
+		},
+		{
+			name:           "AMM is short and price range is fully in long section",
+			price1:         num.NewUint(1900),
+			price2:         num.NewUint(2100),
+			side:           types.SideBuy,
+			expectedVolume: 0,
+			position:       -700,
+		},
 	}
 
 	for _, tt := range tests {