storage: fix get_txid for pre-RCT outputs (#504)

* apply

* apply

* apply

* apply

* revert

* apply

* reduce diffs

* apply

* apply

* fix

Author: hinto-janai

storage/blockchain/src/ops/output.rs

@@ -2,17 +2,23 @@
 
 //---------------------------------------------------------------------------------------------------- Import
 use curve25519_dalek::edwards::CompressedEdwardsY;
-use monero_serai::transaction::{Timelock, Transaction};
+use monero_serai::transaction::Timelock;
 
 use cuprate_database::{
     DbResult, RuntimeError, {DatabaseRo, DatabaseRw},
 };
-use cuprate_helper::{cast::u32_to_usize, crypto::compute_zero_commitment};
-use cuprate_helper::{cast::u64_to_usize, map::u64_to_timelock};
+use cuprate_helper::{
+    cast::{u32_to_usize, u64_to_usize},
+    crypto::compute_zero_commitment,
+    map::u64_to_timelock,
+};
 use cuprate_types::OutputOnChain;
 
 use crate::{
-    ops::macros::{doc_add_block_inner_invariant, doc_error},
+    ops::{
+        macros::{doc_add_block_inner_invariant, doc_error},
+        tx::get_tx_from_id,
+    },
     tables::{
         BlockInfos, BlockTxsHashes, Outputs, RctOutputs, Tables, TablesMut, TxBlobs, TxUnlockTime,
     },
@@ -175,14 +181,16 @@ pub fn output_to_output_on_chain(
 
     let txid = if get_txid {
         let height = u32_to_usize(output.height);
-        let tx_idx = u64_to_usize(output.tx_idx);
-        let txid = if let Some(hash) = table_block_txs_hashes.get(&height)?.get(tx_idx) {
-            *hash
+
+        let miner_tx_id = table_block_infos.get(&height)?.mining_tx_index;
+
+        let txid = if miner_tx_id == output.tx_idx {
+            get_tx_from_id(&miner_tx_id, table_tx_blobs)?.hash()
         } else {
-            let miner_tx_id = table_block_infos.get(&height)?.mining_tx_index;
-            let tx_blob = table_tx_blobs.get(&miner_tx_id)?;
-            Transaction::read(&mut tx_blob.0.as_slice())?.hash()
+            let idx = u64_to_usize(output.tx_idx - miner_tx_id - 1);
+            table_block_txs_hashes.get(&height)?[idx]
         };
+
         Some(txid)
     } else {
         None
@@ -234,8 +242,7 @@ pub fn rct_output_to_output_on_chain(
         let miner_tx_id = table_block_infos.get(&height)?.mining_tx_index;
 
         let txid = if miner_tx_id == rct_output.tx_idx {
-            let tx_blob = table_tx_blobs.get(&miner_tx_id)?;
-            Transaction::read(&mut tx_blob.0.as_slice())?.hash()
+            get_tx_from_id(&miner_tx_id, table_tx_blobs)?.hash()
         } else {
             let idx = u64_to_usize(rct_output.tx_idx - miner_tx_id - 1);
             table_block_txs_hashes.get(&height)?[idx]