token-2022: merge instruction data for confidential Transfer and TransferWithFee (#3410)

Author: samkim-crypto

token/program-2022/src/extension/confidential_transfer/instruction.rs

@@ -219,7 +219,7 @@ pub enum ConfidentialTransferInstruction {
     ///   6.. `[signer]` Required M signer accounts for the SPL Token Multisig account.
     ///
     /// Data expected by this instruction:
-    ///   `TransferWithFeeInstructionData`
+    ///   `TransferInstructionData`
     ///
     TransferWithFee,
 
@@ -418,7 +418,8 @@ pub struct WithdrawInstructionData {
     pub proof_instruction_offset: i8,
 }
 
-/// Data expected by `ConfidentialTransferInstruction::Transfer`
+/// Data expected by `ConfidentialTransferInstruction::Transfer` and
+/// `ConfidentialTransferInstruction::TransferWithFee`
 #[derive(Clone, Copy, Pod, Zeroable)]
 #[repr(C)]
 pub struct TransferInstructionData {
@@ -429,17 +430,6 @@ pub struct TransferInstructionData {
     pub proof_instruction_offset: i8,
 }
 
-/// Data expected by `ConfidentialTransferInstruction::TransferWithFee`
-#[derive(Clone, Copy, Pod, Zeroable)]
-#[repr(C)]
-pub struct TransferWithFeeInstructionData {
-    /// The new source decryptable balance if the transfer succeeds
-    pub new_source_decryptable_available_balance: DecryptableBalance,
-    /// Relative location of the `ProofInstruction::VerifyTransfer` instruction to the
-    /// `Transfer` instruction in the transaction
-    pub proof_instruction_offset: i8,
-}
-
 /// Data expected by `ConfidentialTransferInstruction::ApplyPendingBalance`
 #[derive(Clone, Copy, Pod, Zeroable)]
 #[repr(C)]
@@ -834,7 +824,7 @@ pub fn inner_transfer_with_fee(
         accounts,
         TokenInstruction::ConfidentialTransferExtension,
         ConfidentialTransferInstruction::TransferWithFee,
-        &TransferWithFeeInstructionData {
+        &TransferInstructionData {
             new_source_decryptable_available_balance,
             proof_instruction_offset,
         },

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

@@ -1236,7 +1236,7 @@ pub(crate) fn process_instruction(
             msg!("ConfidentialTransferInstruction::TransferWithFee");
             #[cfg(feature = "zk-ops")]
             {
-                let data = decode_instruction_data::<TransferWithFeeInstructionData>(input)?;
+                let data = decode_instruction_data::<TransferInstructionData>(input)?;
                 process_transfer(
                     program_id,
                     accounts,