rust client: fix TransactionBuilder append to correctly handle CU (#960)

bin/settler/src/settle.rs

@@ -285,6 +285,7 @@ impl<'a> SettleBatchProcessor<'a> {
             payer: fee_payer.pubkey(),
             signers: vec![fee_payer],
             config: client.config().transaction_builder_config.clone(),
+            additional_cus: vec![],
         }
         .transaction_with_blockhash(self.blockhash)
     }

lib/client/src/client.rs

@@ -395,6 +395,7 @@ impl MangoClient {
             payer: payer.pubkey(),
             signers: vec![owner, payer],
             config: client.config.transaction_builder_config.clone(),
+            additional_cus: vec![],
         }
         .send_and_confirm(&client)
         .await?;
@@ -2395,6 +2396,7 @@ impl MangoClient {
             payer: fee_payer.pubkey(),
             signers: vec![fee_payer],
             config: self.client.config.transaction_builder_config.clone(),
+            additional_cus: vec![],
         })
     }
 
@@ -2409,6 +2411,7 @@ impl MangoClient {
             payer: fee_payer.pubkey(),
             signers: vec![fee_payer],
             config: self.client.config.transaction_builder_config.clone(),
+            additional_cus: vec![],
         }
         .simulate(&self.client)
         .await
@@ -2518,6 +2521,7 @@ pub struct TransactionBuilder {
     pub signers: Vec<Arc<Keypair>>,
     pub payer: Pubkey,
     pub config: TransactionBuilderConfig,
+    pub additional_cus: Vec<u32>,
 }
 
 pub type SimulateTransactionResponse =
@@ -2558,10 +2562,15 @@ impl TransactionBuilder {
 
         let cu_per_ix = self.config.compute_budget_per_instruction.unwrap_or(0);
         if !has_compute_unit_limit && cu_per_ix > 0 {
-            let ix_count: u32 = (ixs.len() - cu_instructions).try_into().unwrap();
+            let ix_count: u32 = (ixs.len() - cu_instructions - self.additional_cus.len())
+                .try_into()
+                .unwrap();
+            let additional_cu_sum: u32 = self.additional_cus.iter().sum();
             ixs.insert(
                 0,
-                ComputeBudgetInstruction::set_compute_unit_limit(cu_per_ix * ix_count),
+                ComputeBudgetInstruction::set_compute_unit_limit(
+                    cu_per_ix * ix_count + additional_cu_sum,
+                ),
             );
         }
 
@@ -2649,8 +2658,10 @@ impl TransactionBuilder {
     }
 
     pub fn append(&mut self, prepared_instructions: PreparedInstructions) {
-        self.instructions
-            .extend(prepared_instructions.to_instructions());
+        // Do NOT use to instruction s it would add a CU limit
+        // That CU limit would overwrite the one computed by the transaction builder
+        self.instructions.extend(prepared_instructions.instructions);
+        self.additional_cus.push(prepared_instructions.cu);
     }
 }
 

lib/client/src/swap/jupiter_v6.rs

@@ -204,6 +204,7 @@ impl<'a> JupiterV6<'a> {
             .send()
             .await
             .context("quote request to jupiter")?;
+
         let quote: QuoteResponse =
             util::http_error_handling(response).await.with_context(|| {
                 format!("error requesting jupiter route between {input_mint} and {output_mint}")
@@ -392,6 +393,7 @@ impl<'a> JupiterV6<'a> {
                 .config()
                 .transaction_builder_config
                 .clone(),
+            additional_cus: vec![],
         })
     }
 

lib/client/src/swap/sanctum.rs

@@ -321,6 +321,7 @@ impl<'a> Sanctum<'a> {
                 .config()
                 .transaction_builder_config
                 .clone(),
+            additional_cus: vec![],
         })
     }
 

lib/client/src/util.rs

@@ -3,6 +3,7 @@ use solana_sdk::instruction::Instruction;
 
 use anchor_lang::prelude::{AccountMeta, Pubkey};
 use anyhow::Context;
+use tracing::warn;
 
 /// Some Result<> types don't convert to anyhow::Result nicely. Force them through stringification.
 pub trait AnyhowWrap {
@@ -80,8 +81,15 @@ pub async fn http_error_handling<T: serde::de::DeserializeOwned>(
     if !status.is_success() {
         anyhow::bail!("http request failed, status: {status}, body: {response_text}");
     }
-    serde_json::from_str::<T>(&response_text)
-        .with_context(|| format!("response has unexpected format, body: {response_text}"))
+    let object = serde_json::from_str::<T>(&response_text);
+
+    match object {
+        Ok(o) => Ok(o),
+        Err(e) => {
+            warn!("{}", e);
+            anyhow::bail!("response has unexpected format, body: {response_text}")
+        }
+    }
 }
 
 pub fn to_readonly_account_meta(pubkey: Pubkey) -> AccountMeta {