fix(revive): handle transaction hash conflicts during re-org (paritytech#10950)

## Summary

Fixes a UNIQUE constraint violation when processing blocks after a
re-org:
```
UNIQUE constraint failed: transaction_hashes.transaction_hash
```

## Problem

When a blockchain re-org occurs:
1. Block A contains transaction TX1 → stored in `transaction_hashes`
2. Server restarts (clearing the in-memory `block_number_to_hashes` map)
3. Re-org happens, Block B (different hash) now contains the same TX1
4. INSERT fails because TX1 already exists with old block_hash

---------

Co-authored-by: cmd[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: pgherveou

prdoc/pr_10950.prdoc

@@ -0,0 +1,13 @@
+title: 'fix(revive): handle transaction hash conflicts during re-org'
+doc:
+- audience: Runtime Dev
+  description: "## Summary\n\nFixes a UNIQUE constraint violation when processing\
+    \ blocks after a re-org:\n```\nUNIQUE constraint failed: transaction_hashes.transaction_hash\n\
+    ```\n\n## Problem\n\nWhen a blockchain re-org occurs:\n1. Block A contains transaction\
+    \ TX1 \u2192 stored in `transaction_hashes`\n2. Server restarts (clearing the\
+    \ in-memory `block_number_to_hashes` map)\n3. Re-org happens, Block B (different\
+    \ hash) now contains the same TX1\n4. INSERT fails because TX1 already exists\
+    \ with old block_hash"
+crates:
+- name: pallet-revive-eth-rpc
+  bump: patch

substrate/frame/revive/rpc/.sqlx/query-5c0ea8efbd2591e3ede3833acfcadf2d552140a20d84edbf90583da4619bcf2a.json

@@ -334,7 +334,7 @@ impl<B: BlockInfoProvider> ReceiptProvider<B> {
 
 				query!(
 					r#"
-					INSERT INTO transaction_hashes (transaction_hash, block_hash, transaction_index)
+					INSERT OR REPLACE INTO transaction_hashes (transaction_hash, block_hash, transaction_index)
 					VALUES ($1, $2, $3)
 					"#,
 					transaction_hash,
@@ -765,6 +765,56 @@ mod tests {
 		return Ok(());
 	}
 
+	#[sqlx::test]
+	async fn test_reorg_same_transaction_hash(pool: SqlitePool) -> anyhow::Result<()> {
+		let provider = setup_sqlite_provider(pool).await;
+
+		// Build two blocks at the same height with the same transaction hash
+		let tx_hash = H256::from([42u8; 32]);
+
+		// Block A at height 1
+		let block_a = MockBlockInfo { hash: H256::from([1u8; 32]), number: 1 };
+		let ethereum_hash_a = H256::from([2u8; 32]);
+		let receipts_a = vec![(
+			TransactionSigned::default(),
+			ReceiptInfo {
+				transaction_hash: tx_hash,
+				transaction_index: U256::from(0),
+				..Default::default()
+			},
+		)];
+
+		provider.insert(&block_a, &receipts_a, &ethereum_hash_a).await?;
+
+		// Verify transaction points to block A
+		let (found_hash, _) = provider.find_transaction(&tx_hash).await.unwrap();
+		assert_eq!(found_hash, block_a.hash);
+
+		// Clear the in-memory map to simulate server restart
+		provider.block_number_to_hashes.lock().await.clear();
+
+		// Block B at same height 1 (re-org) with SAME transaction
+		let block_b = MockBlockInfo { hash: H256::from([3u8; 32]), number: 1 };
+		let ethereum_hash_b = H256::from([4u8; 32]);
+		let receipts_b = vec![(
+			TransactionSigned::default(),
+			ReceiptInfo {
+				transaction_hash: tx_hash, // Same tx hash!
+				transaction_index: U256::from(0),
+				..Default::default()
+			},
+		)];
+
+		// This should NOT fail with UNIQUE constraint violation
+		provider.insert(&block_b, &receipts_b, &ethereum_hash_b).await?;
+
+		// Transaction should now point to block B
+		let (found_hash, _) = provider.find_transaction(&tx_hash).await.unwrap();
+		assert_eq!(found_hash, block_b.hash);
+
+		Ok(())
+	}
+
 	#[sqlx::test]
 	async fn test_receipts_count_per_block(pool: SqlitePool) -> anyhow::Result<()> {
 		let provider = setup_sqlite_provider(pool).await;