program: use saturating_sub for number_of_users (#1616)

0xbigz · web-flow · commit ede19b8319be · 2025-05-15T13:59:16.000-04:00
* program: use saturating_sub for number_of_users

* update CHANGELOG.md
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -13,6 +13,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixes
 
+- program: safely use saturating sub number_of_users fields per market ([#1616](https://github.com/drift-labs/protocol-v2/pull/1616))
+
 ### Breaking
 
 ## [2.120.0] - 2025-04-29
diff --git a/programs/drift/src/controller/position.rs b/programs/drift/src/controller/position.rs
@@ -192,10 +192,10 @@ pub fn update_position_and_market(
         market.number_of_users_with_base = market.number_of_users_with_base.safe_add(1)?;
     } else if let PositionUpdateType::Close = update_type {
         if new_base_asset_amount == 0 && new_quote_asset_amount == 0 {
-            market.number_of_users = market.number_of_users.safe_sub(1)?;
+            market.number_of_users = market.number_of_users.saturating_sub(1);
         }
 
-        market.number_of_users_with_base = market.number_of_users_with_base.safe_sub(1)?;
+        market.number_of_users_with_base = market.number_of_users_with_base.saturating_sub(1);
     }
 
     market.amm.quote_asset_amount = market

Original file line number	Diff line number	Diff line change
`@@ -192,10 +192,10 @@ pub fn update_position_and_market(`
`192`	`192`	`market.number_of_users_with_base = market.number_of_users_with_base.safe_add(1)?;`
`193`	`193`	`} else if let PositionUpdateType::Close = update_type {`
`194`	`194`	`if new_base_asset_amount == 0 && new_quote_asset_amount == 0 {`
`195`		`- market.number_of_users = market.number_of_users.safe_sub(1)?;`
	`195`	`+ market.number_of_users = market.number_of_users.saturating_sub(1);`
`196`	`196`	`}`
`197`	`197`
`198`		`- market.number_of_users_with_base = market.number_of_users_with_base.safe_sub(1)?;`
	`198`	`+ market.number_of_users_with_base = market.number_of_users_with_base.saturating_sub(1);`
`199`	`199`	`}`
`200`	`200`
`201`	`201`	`market.amm.quote_asset_amount = market`