Remove unused fields from ConstructedTransaction
What the developer wrote
Authored by Jeffrey Czyz
Remove unused fields from ConstructedTransaction
The output values are never used so there's no need to persist them.
If needed, they can be re-computed though the shared output's local
and remote amounts would be lost.
What changed, and why it matters
This commit is a simple code cleanup: it removes two bookkeeping fields (local_outputs_value_satoshis and remote_outputs_value_satoshis) from an internal transaction-construction structure because they were never actually used. The change also renumbers the remaining data fields saved to disk. There is no security-relevant behavior change visible in the diff.
No security action needed. Treat as routine refactoring/cleanup.
Security signals we found
No strong security signals were identified.
Evidence from the diff
The patch deletes the local_outputs_value_satoshis and remote_outputs_value_satoshis u64 fields from ConstructedTransaction in lightning/src/ln/interactivetxs.rs, removes their computation from the constructor, drops the corresponding TLV serialization tags, and updates a test fixture. The commit message explicitly states the fields are unused. No logic that validates, signs, or broadcasts transactions is altered.
Changed components
lightning/src/ln/interactivetxs.rsConstructedTransaction structInspect captured patch +7 / −24
diff --git a/lightning/src/ln/interactivetxs.rs b/lightning/src/ln/interactivetxs.rs
index 56800e1..10f3a31 100644
--- a/lightning/src/ln/interactivetxs.rs
+++ b/lightning/src/ln/interactivetxs.rs
@@ -203,10 +203,7 @@ pub(crate) struct ConstructedTransaction {
tx: Transaction,
local_inputs_value_satoshis: u64,
- local_outputs_value_satoshis: u64,
-
remote_inputs_value_satoshis: u64,
- remote_outputs_value_satoshis: u64,
shared_input_index: Option<u32>,
}
@@ -253,10 +250,8 @@ impl_writeable_tlv_based!(ConstructedTransaction, {
(5, output_metadata, required),
(7, tx, required),
(9, local_inputs_value_satoshis, required),
- (11, local_outputs_value_satoshis, required),
- (13, remote_inputs_value_satoshis, required),
- (15, remote_outputs_value_satoshis, required),
- (17, shared_input_index, option),
+ (11, remote_inputs_value_satoshis, required),
+ (13, shared_input_index, option),
});
impl ConstructedTransaction {
@@ -280,14 +275,7 @@ impl ConstructedTransaction {
.inputs
.iter()
.fold(0u64, |value, (_, input)| value.saturating_add(input.local_value()));
-
- let local_outputs_value_satoshis = context
- .outputs
- .iter()
- .fold(0u64, |value, (_, output)| value.saturating_add(output.local_value()));
-
let remote_inputs_value_satoshis = context.remote_inputs_value();
- let remote_outputs_value_satoshis = context.remote_outputs_value();
let satisfaction_weight =
Weight::from_wu(context.inputs.iter().fold(0u64, |value, (_, input)| {
@@ -326,16 +314,13 @@ impl ConstructedTransaction {
Ok(Self {
holder_is_initiator: context.holder_is_initiator,
- local_inputs_value_satoshis,
- local_outputs_value_satoshis,
-
- remote_inputs_value_satoshis,
- remote_outputs_value_satoshis,
-
input_metadata,
output_metadata,
tx,
+ local_inputs_value_satoshis,
+ remote_inputs_value_satoshis,
+
shared_input_index,
})
}
@@ -3321,10 +3306,8 @@ mod tests {
input_metadata,
output_metadata: vec![], // N/A for test
tx: transaction.clone(),
- local_inputs_value_satoshis: 0, // N/A for test
- local_outputs_value_satoshis: 0, // N/A for test
- remote_inputs_value_satoshis: 0, // N/A for test
- remote_outputs_value_satoshis: 0, // N/A for test
+ local_inputs_value_satoshis: 0, // N/A for test
+ remote_inputs_value_satoshis: 0, // N/A for test
shared_input_index: None,
};
Why this scored 15/100
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