fix(PCL): don't update LP profits on withdrawal (#469)

Author: epanchee

contracts/pair_concentrated/src/contract.rs

@@ -41,7 +41,6 @@ use astroport_pcl_common::utils::{
     accumulate_prices, assert_max_spread, before_swap_check, calc_last_prices, check_asset_infos,
     check_cw20_in_pool, compute_swap, get_share_in_assets, mint_liquidity_token_message,
 };
-use astroport_pcl_common::{calc_d, get_xcp};
 
 use crate::error::ContractError;
 use crate::state::{BALANCES, CONFIG, OBSERVATIONS, OWNERSHIP_PROPOSAL};
@@ -559,7 +558,7 @@ fn withdraw_liquidity(
     info: MessageInfo,
     assets: Vec<Asset>,
 ) -> Result<Response, ContractError> {
-    let mut config = CONFIG.load(deps.storage)?;
+    let config = CONFIG.load(deps.storage)?;
 
     let Coin { amount, denom } = one_coin(&info)?;
 
@@ -587,18 +586,6 @@ fn withdraw_liquidity(
         return Err(StdError::generic_err("Imbalanced withdraw is currently disabled").into());
     };
 
-    // decrease XCP
-    let mut xs = pools.iter().map(|a| a.amount).collect_vec();
-
-    xs[0] -= refund_assets[0].amount;
-    xs[1] -= refund_assets[1].amount;
-    xs[1] *= config.pool_state.price_state.price_scale;
-    let amp_gamma = config.pool_state.get_amp_gamma(&env);
-    let d = calc_d(&xs, &amp_gamma)?;
-    config.pool_state.price_state.xcp_profit_real =
-        get_xcp(d, config.pool_state.price_state.price_scale)
-            / (total_share - amount).to_decimal256(LP_TOKEN_PRECISION)?;
-
     let refund_assets = refund_assets
         .into_iter()
         .map(|asset| {
@@ -637,8 +624,6 @@ fn withdraw_liquidity(
         }
     }
 
-    CONFIG.save(deps.storage, &config)?;
-
     Ok(Response::new().add_messages(messages).add_attributes(vec![
         attr("action", "withdraw_liquidity"),
         attr("sender", info.sender),

contracts/pair_concentrated/tests/pair_concentrated_integration.rs

@@ -1713,6 +1713,55 @@ fn check_correct_fee_share() {
     assert!(config.fee_share.is_none());
 }
 
+#[test]
+fn test_lsd_corner_case() {
+    let owner = Addr::unchecked("owner");
+
+    let test_coins = vec![TestCoin::native("uusd"), TestCoin::native("uluna")];
+
+    let params = ConcentratedPoolParams {
+        amp: f64_to_dec(500.0),
+        gamma: f64_to_dec(0.01),
+        mid_fee: f64_to_dec(0.0003),
+        out_fee: f64_to_dec(0.0045),
+        fee_gamma: f64_to_dec(0.3),
+        repeg_profit_threshold: f64_to_dec(0.00000001),
+        min_price_scale_delta: f64_to_dec(0.0000055),
+        price_scale: f64_to_dec(1.5915113196549202),
+        ..common_pcl_params()
+    };
+
+    let mut helper = Helper::new(&owner, test_coins.clone(), params).unwrap();
+
+    helper.app.next_block(61200);
+
+    let assets = vec![
+        helper.assets[&test_coins[0]].with_balance(10000u128),
+        helper.assets[&test_coins[1]].with_balance(10000u128),
+    ];
+    helper.provide_liquidity(&owner, &assets).unwrap();
+
+    helper.app.next_block(240);
+    let assets = vec![
+        helper.assets[&test_coins[0]].with_balance(20000u128),
+        helper.assets[&test_coins[1]].with_balance(20000u128),
+    ];
+    helper.provide_liquidity(&owner, &assets).unwrap();
+
+    helper.app.next_block(6000);
+    helper.withdraw_liquidity(&owner, 19519, vec![]).unwrap();
+
+    assert!(
+        helper
+            .query_config()
+            .unwrap()
+            .pool_state
+            .price_state
+            .xcp_profit_real
+            >= Decimal256::one()
+    );
+}
+
 #[test]
 fn check_small_trades() {
     let owner = Addr::unchecked("owner");

contracts/pair_concentrated_duality/src/execute.rs

@@ -23,7 +23,6 @@ use astroport_pcl_common::utils::{
     accumulate_prices, assert_max_spread, before_swap_check, calc_last_prices, compute_swap,
     get_share_in_assets, mint_liquidity_token_message,
 };
-use astroport_pcl_common::{calc_d, get_xcp};
 
 use crate::error::ContractError;
 use crate::instantiate::LP_TOKEN_PRECISION;
@@ -399,14 +398,6 @@ fn withdraw_liquidity(
     );
     ob_state.save(deps.storage)?;
 
-    // decrease XCP
-    xs[1] *= config.pool_state.price_state.price_scale;
-    let amp_gamma = config.pool_state.get_amp_gamma(&env);
-    let d = calc_d(&xs, &amp_gamma)?;
-    config.pool_state.price_state.xcp_profit_real =
-        get_xcp(d, config.pool_state.price_state.price_scale)
-            / (total_share - amount).to_decimal256(LP_TOKEN_PRECISION)?;
-
     CONFIG.save(deps.storage, &config)?;
 
     Ok(response.add_submessages(submsgs).add_attributes([

contracts/pair_concentrated_sale_tax/src/contract.rs

@@ -42,7 +42,6 @@ use astroport_pcl_common::utils::{
     accumulate_prices, assert_max_spread, before_swap_check, calc_last_prices, check_asset_infos,
     check_cw20_in_pool, get_share_in_assets, mint_liquidity_token_message,
 };
-use astroport_pcl_common::{calc_d, get_xcp};
 
 use crate::error::ContractError;
 use crate::state::{BALANCES, CONFIG, OBSERVATIONS, OWNERSHIP_PROPOSAL, TAX_CONFIG};
@@ -569,7 +568,7 @@ fn withdraw_liquidity(
     info: MessageInfo,
     assets: Vec<Asset>,
 ) -> Result<Response, ContractError> {
-    let mut config = CONFIG.load(deps.storage)?;
+    let config = CONFIG.load(deps.storage)?;
 
     let Coin { amount, denom } = one_coin(&info)?;
 
@@ -597,18 +596,6 @@ fn withdraw_liquidity(
         return Err(StdError::generic_err("Imbalanced withdraw is currently disabled").into());
     };
 
-    // decrease XCP
-    let mut xs = pools.iter().map(|a| a.amount).collect_vec();
-
-    xs[0] -= refund_assets[0].amount;
-    xs[1] -= refund_assets[1].amount;
-    xs[1] *= config.pool_state.price_state.price_scale;
-    let amp_gamma = config.pool_state.get_amp_gamma(&env);
-    let d = calc_d(&xs, &amp_gamma)?;
-    config.pool_state.price_state.xcp_profit_real =
-        get_xcp(d, config.pool_state.price_state.price_scale)
-            / (total_share - amount).to_decimal256(LP_TOKEN_PRECISION)?;
-
     let refund_assets = refund_assets
         .into_iter()
         .map(|asset| {
@@ -647,8 +634,6 @@ fn withdraw_liquidity(
         }
     }
 
-    CONFIG.save(deps.storage, &config)?;
-
     Ok(Response::new().add_messages(messages).add_attributes(vec![
         attr("action", "withdraw_liquidity"),
         attr("sender", info.sender),