after rebase

miden-lib/asm/kernels/transaction/api.masm

@@ -525,7 +525,7 @@ end
 #! tag is the tag to be included in the note.
 #! note_type is the note storage type
 #! RECIPIENT is the recipient of the note.
-#! note_idx is the index of the the note.
+#! note_idx is the index of the crated note.
 export.create_note
     # authenticate that the procedure invocation originates from the account context
     exec.authenticate_account_origin
@@ -543,8 +543,7 @@ export.create_note
     # => [note_idx, 0, 0, 0, 0, 0]
 end
 
-#! Adds an ASSET to the specified note and returns the index of the note
-#! to which the asset is added.
+#! Adds the ASSET to the note specified by the index.
 #!
 #! Inputs: [note_idx, ASSET]
 #! Outputs: [note_idx, 0, 0, 0, 0]

miden-lib/asm/miden/kernels/tx/tx.masm

@@ -251,14 +251,14 @@ proc.add_fungible_asset_to_note
     # => [note_ptr, note_idx]
 end
 
-#! Creates a new note and returns the index of the created note.
+#! Creates a new note and returns the index of the note.
 #!
 #! Inputs: [tag, note_type, RECIPIENT]
 #! Outputs: [note_idx]
 #!
 #! - tag is the tag to be included in the note.
 #! - RECIPIENT defines spend conditions for the note.
-#! - note_idx is the index of the the note.
+#! - note_idx is the index of the crated note.
 #!
 #! Panics if:
 #! - the note_type is not valid.
@@ -312,13 +312,12 @@ export.create_note
     # => [note_idx]
 end
 
-#! Adds an ASSET to the specified note and returns the index of the note
-#! to which the asset is added.
+#! Adds the ASSET to the note specified by the index.
 #!
 #! Inputs: [note_idx, ASSET]
 #! Outputs: [note_idx]
 #!
-#! note_idx is the index of the the note to which the asset is added.
+#! - note_idx is the index of the the note to which the asset is added.
 #! - ASSET can be a fungible or non-fungible asset.
 #!
 #! Panics if:

miden-lib/asm/miden/tx.masm

@@ -61,7 +61,7 @@ end
 #! tag is the tag to be included in the note.
 #! note_type is the storage type of the note
 #! RECIPIENT is the recipient of the note.
-#! note_idx is the index of the the note to which the asset is added.
+#! note_idx is the index of the crated note.
 export.create_note
     syscall.create_note
     # => [note_idx, ZERO, 0]
@@ -71,13 +71,12 @@ export.create_note
     # => [note_idx]
 end
 
-#! Adds an ASSET to the specified note and returns the index of the note
-#! to which the asset is added.
+#! Adds the ASSET to the note specified by the index.
 #!
 #! Inputs: [note_idx, ASSET]
 #! Outputs: [note_idx]
 #!
-#! note_idx is the index of the the note to which the asset is added.
+#! note_idx is the index of the note to which the asset is added.
 #! ASSET can be a fungible or non-fungible asset.
 export.add_asset_to_note
     syscall.add_asset_to_note

miden-lib/src/transaction/errors.rs

@@ -23,7 +23,6 @@ pub enum TransactionKernelError {
     MalformedAssetOnAccountVaultUpdate(AssetError),
     MalformedNoteInputs(NoteError),
     MalformedNoteMetadata(NoteError),
-    MalformedNoteIndex(u64),
     MalformedNoteScript(Vec<Felt>),
     MalformedNoteType(NoteError),
     MalformedRecipientData(Vec<Felt>),
@@ -68,9 +67,6 @@ impl fmt::Display for TransactionKernelError {
             TransactionKernelError::MalformedNoteMetadata(err) => {
                 write!(f, "Note metadata created by the event handler is not well formed {err}")
             },
-            TransactionKernelError::MalformedNoteIndex(err) => {
-                write!(f, "Note index is malformed {err}")
-            },
             TransactionKernelError::MalformedNoteScript(data) => {
                 write!( f, "Note script data extracted from the advice map by the event handler is not well formed {data:?}")
             },

miden-tx/src/host/mod.rs

@@ -1,8 +1,7 @@
 use alloc::{collections::BTreeMap, rc::Rc, string::ToString, vec::Vec};
 
 use miden_lib::transaction::{
-    memory::{ACCT_STORAGE_ROOT_PTR, CURRENT_CONSUMED_NOTE_PTR},
-    TransactionEvent, TransactionKernelError, TransactionTrace,
+    memory::CURRENT_CONSUMED_NOTE_PTR, TransactionEvent, TransactionKernelError, TransactionTrace,
 };
 use miden_objects::{
     accounts::{AccountDelta, AccountId, AccountStorage, AccountStub},
@@ -118,6 +117,8 @@ impl<A: AdviceProvider, T: TransactionAuthenticator> TransactionHost<A, T> {
 
         let note_idx: usize = stack[9].as_int() as usize;
 
+        assert_eq!(note_idx, self.output_notes.len(), "note index mismatch");
+
         let note_builder = OutputNoteBuilder::new(stack, &self.adv_provider)?;
 
         self.output_notes.insert(note_idx, note_builder);
@@ -135,21 +136,16 @@ impl<A: AdviceProvider, T: TransactionAuthenticator> TransactionHost<A, T> {
         let stack = process.get_stack_state();
         //# => [ASSET, note_ptr, num_of_assets, note_idx]
 
-        // this is a safe conversion because the note index (in theory) is always a u64
-        // in theory, the user can provide any note index. However, we already check in
-        // the kernel that the note index < MAX_OUTPUT_NOTES_PER_TX
-        let note_idx_u64 = stack[6].as_int();
-        if note_idx_u64 >= usize::MAX as u64 {
-            return Err(TransactionKernelError::MalformedNoteIndex(note_idx_u64));
-        }
-        let note_idx = note_idx_u64 as usize;
+        let note_idx = stack[6].as_int();
+        assert!(note_idx < self.output_notes.len() as u64);
+        let node_idx = note_idx as usize;
 
         let asset = Asset::try_from(process.get_stack_word(0))
             .map_err(TransactionKernelError::MalformedAsset)?;
 
         let note_builder = self
             .output_notes
-            .get_mut(&note_idx)
+            .get_mut(&node_idx)
             .ok_or_else(|| TransactionKernelError::MissingNote(format!("{:?}", &note_idx)))?;
 
         note_builder.add_asset(asset)?;