From daff63113a180b4c31cfeb5a8ea07ee31896be36 Mon Sep 17 00:00:00 2001
From: NicolasCantu <nicolas.cantu@pm.me>
Date: Tue, 8 Apr 2025 15:59:49 +0200
Subject: [PATCH] Don't only look last output for commitments

---
 src/process.rs | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/src/process.rs b/src/process.rs
index 9a5c138..9748c80 100644
--- a/src/process.rs
+++ b/src/process.rs
@@ -546,18 +546,19 @@ pub fn check_tx_for_process_updates(tx: &Transaction) -> anyhow::Result<OutPoint
         let process_tip = if let Ok(tip) = process.get_process_tip() { tip } else { continue };
         for input in &tx.input {
             if process_tip == input.previous_output {
-                log::debug!("Find a match for process tip {}", process_tip);
+                log::debug!("Found a match for process tip {}", process_tip);
                 // This transaction commits a new state
-                let last_output = &tx.output.get(tx.output.len()-1).unwrap().script_pubkey;
-                let mut state_id = [0u8; 32];
-                if last_output.is_op_return() {
-                    if last_output.as_bytes().len() != 34 {
-                        return Err(anyhow::Error::msg("commited data is not 32B long"));
-                    }
-                    state_id.clone_from_slice(&last_output.as_bytes()[2..]);
-                } else {
-                    return Err(anyhow::Error::msg("last output must be op_return"));
+                // Look for the op_return
+                let op_return_outputs: Vec<_> = tx.output.iter().filter(|o| o.script_pubkey.is_op_return()).collect();
+                if op_return_outputs.len() != 1 {
+                    return Err(anyhow::Error::msg("Transaction must contain exactly one op_return output"));
                 }
+                let mut state_id = [0u8; 32];
+                let data = &op_return_outputs.into_iter().next().unwrap().script_pubkey.as_bytes()[2..];
+                if data.len() != 32 {
+                    return Err(anyhow::Error::msg("commited data is not 32B long"));
+                }
+                state_id.clone_from_slice(data);
                 // Check if we know about the commited state
                 let new_state: ProcessState;
                 if let Ok(commited_state) = process.get_state_for_id(&state_id) {