feedback: rework rent check and test tx dedupe

Author: buffalojoec

token/client/src/token.rs

@@ -41,8 +41,8 @@ use {
                 ConfidentialTransferFeeConfig,
             },
             cpi_guard, default_account_state, group_pointer, interest_bearing_mint, memo_transfer,
-            metadata_pointer, transfer_fee, transfer_hook, BaseStateWithExtensions, ExtensionType,
-            StateWithExtensions, StateWithExtensionsOwned,
+            metadata_pointer, transfer_fee, transfer_hook, BaseStateWithExtensions, Extension,
+            ExtensionType, StateWithExtensionsOwned,
         },
         instruction, offchain,
         proof::ProofLocation,
@@ -3655,14 +3655,18 @@ where
     ) -> TokenResult<u64> {
         let account = self.get_account(self.pubkey).await?;
         let account_lamports = account.lamports;
-        let mint_state = StateWithExtensions::<Mint>::unpack(&account.data)?;
-        let new_account_len = mint_state.try_get_new_account_len::<V>(size_of::<V>())?;
-        let new_rent_exempt_minimum = self
-            .client
-            .get_minimum_balance_for_rent_exemption(new_account_len)
-            .await
-            .map_err(TokenError::Client)?;
-        Ok(new_rent_exempt_minimum.saturating_sub(account_lamports))
+        let mint_state = self.unpack_mint_info(account)?;
+        if mint_state.get_extension::<V>().is_ok() {
+            Ok(0)
+        } else {
+            let new_account_len = mint_state.try_get_new_account_len::<V>()?;
+            let new_rent_exempt_minimum = self
+                .client
+                .get_minimum_balance_for_rent_exemption(new_account_len)
+                .await
+                .map_err(TokenError::Client)?;
+            Ok(new_rent_exempt_minimum.saturating_sub(account_lamports))
+        }
     }
 
     /// Initialize token-group on a mint

token/program-2022-test/tests/program_test.rs

@@ -146,7 +146,7 @@ impl TestContext {
         let token_unchecked = Token::new_native(Arc::clone(&client), &id(), Arc::new(payer));
         self.token_context = Some(TokenContext {
             decimals: native_mint::DECIMALS,
-            mint_authority: Keypair::new(), /*bogus*/
+            mint_authority: Keypair::new(), /* bogus */
             token,
             token_unchecked,
             alice: Keypair::new(),

token/program-2022-test/tests/token_group_initialize.rs

@@ -131,7 +131,7 @@ async fn success_initialize() {
             &payer_pubkey,
             &token_context.mint_authority.pubkey(),
             &update_authority,
-            max_size,
+            12, // Change so we get a different transaction
             &[&token_context.mint_authority],
         )
         .await
@@ -140,7 +140,7 @@ async fn success_initialize() {
         error,
         TokenClientError::Client(Box::new(TransportError::TransactionError(
             TransactionError::InstructionError(
-                1,
+                0, // No additional rent
                 InstructionError::Custom(TokenError::ExtensionAlreadyInitialized as u32)
             )
         )))

token/program-2022/src/extension/token_group/processor.rs

@@ -5,8 +5,8 @@ use {
         check_program_account,
         error::TokenError,
         extension::{
-            group_pointer::GroupPointer, BaseStateWithExtensions, ExtensionType,
-            StateWithExtensions, StateWithExtensionsMut,
+            alloc_and_serialize, group_pointer::GroupPointer, BaseStateWithExtensions,
+            StateWithExtensions,
         },
         state::Mint,
     },
@@ -25,16 +25,6 @@ use {
     },
 };
 
-fn realloc_mint(mint_info: &AccountInfo, extension: ExtensionType) -> Result<(), ProgramError> {
-    let extension_len = extension.try_get_tlv_len()?;
-    let new_account_len = mint_info
-        .data_len()
-        .checked_add(extension_len)
-        .ok_or::<ProgramError>(TokenError::Overflow.into())?;
-    mint_info.realloc(new_account_len, false)?;
-    Ok(())
-}
-
 /// Processes a [InitializeGroup](enum.TokenGroupInstruction.html) instruction.
 pub fn process_initialize_group(
     _program_id: &Pubkey,
@@ -78,15 +68,10 @@ pub fn process_initialize_group(
         }
     }
 
-    // Reallocate the mint for the new extension
-    realloc_mint(mint_info, ExtensionType::TokenGroup)?;
-
     // Allocate a TLV entry for the space and write it in
     // Assumes that there's enough SOL for the new rent-exemption
-    let mut mint_data = mint_info.try_borrow_mut_data()?;
-    let mut mint = StateWithExtensionsMut::<Mint>::unpack(&mut mint_data)?;
-    let group = mint.init_extension::<TokenGroup>(false)?;
-    *group = TokenGroup::new(mint_info.key, data.update_authority, data.max_size.into());
+    let group = TokenGroup::new(mint_info.key, data.update_authority, data.max_size.into());
+    alloc_and_serialize::<Mint, TokenGroup>(group_info, &group, false)?;
 
     Ok(())
 }