From 1bb198a0e3cbca2e1c69e4133c2eced1cdbbf5b1 Mon Sep 17 00:00:00 2001
From: Casey Rodarmor <casey@rodarmor.com>
Date: Wed, 27 Mar 2024 19:53:09 -0700
Subject: [PATCH] Ignore errors in invalid scripts

---
 src/index/updater/rune_updater.rs |  5 +-
 src/runes.rs                      | 35 ++++++++++++++
 src/runes/runestone.rs            | 76 +++++++++++++++++++++++++------
 3 files changed, 101 insertions(+), 15 deletions(-)

diff --git a/src/index/updater/rune_updater.rs b/src/index/updater/rune_updater.rs
index 3cecf9401d..45bdecbda7 100644
--- a/src/index/updater/rune_updater.rs
+++ b/src/index/updater/rune_updater.rs
@@ -362,7 +362,10 @@ impl<'a, 'tx, 'client> RuneUpdater<'a, 'tx, 'client> {
       };
 
       for instruction in tapscript.instructions() {
-        let instruction = instruction?;
+        // ignore errors, since the extracted script may not be valid
+        let Ok(instruction) = instruction else {
+          break;
+        };
 
         let Some(pushbytes) = instruction.push_bytes() else {
           continue;
diff --git a/src/runes.rs b/src/runes.rs
index e9fa662c8d..1c9628d4d5 100644
--- a/src/runes.rs
+++ b/src/runes.rs
@@ -5392,4 +5392,39 @@ mod tests {
 
     context.assert_runes([], []);
   }
+
+  #[test]
+  fn tx_commits_to_rune_ignores_invalid_script() {
+    let context = Context::builder().arg("--index-runes").build();
+
+    context.mine_blocks(1);
+
+    let runestone = Runestone {
+      etching: Some(Etching {
+        rune: Some(Rune(RUNE)),
+        terms: Some(Terms {
+          amount: Some(1000),
+          ..default()
+        }),
+        ..default()
+      }),
+      ..default()
+    };
+
+    let mut witness = Witness::new();
+
+    witness.push([opcodes::all::OP_PUSHDATA4.to_u8()]);
+    witness.push([]);
+
+    context.rpc_server.broadcast_tx(TransactionTemplate {
+      inputs: &[(1, 0, 0, witness)],
+      op_return: Some(runestone.encipher()),
+      outputs: 1,
+      ..default()
+    });
+
+    context.mine_blocks(1);
+
+    context.assert_runes([], []);
+  }
 }
diff --git a/src/runes/runestone.rs b/src/runes/runestone.rs
index 28c2bb1334..4de223e374 100644
--- a/src/runes/runestone.rs
+++ b/src/runes/runestone.rs
@@ -17,6 +17,7 @@ struct Message {
   fields: HashMap<u128, VecDeque<u128>>,
 }
 
+#[derive(Debug, PartialEq)]
 enum Payload {
   Valid(Vec<u8>),
   Invalid,
@@ -264,8 +265,9 @@ impl Runestone {
         continue;
       }
 
-      // followed by the protocol identifier
-      if instructions.next().transpose()? != Some(Instruction::Op(MAGIC_NUMBER)) {
+      // followed by the protocol identifier, ignoring errors, since OP_RETURN
+      // scripts may be invalid
+      if instructions.next().transpose().ok().flatten() != Some(Instruction::Op(MAGIC_NUMBER)) {
         continue;
       }
 
@@ -273,7 +275,7 @@ impl Runestone {
       let mut payload = Vec::new();
 
       for result in instructions {
-        if let Instruction::PushBytes(push) = result? {
+        if let Ok(Instruction::PushBytes(push)) = result {
           payload.extend_from_slice(push.as_bytes());
         } else {
           return Ok(Some(Payload::Invalid));
@@ -433,7 +435,7 @@ mod tests {
   }
 
   #[test]
-  fn deciphering_valid_runestone_with_invalid_script_postfix_returns_script_error() {
+  fn deciphering_valid_runestone_with_invalid_script_postfix_returns_invalid_payload() {
     let mut script_pubkey = script::Builder::new()
       .push_opcode(opcodes::all::OP_RETURN)
       .push_opcode(MAGIC_NUMBER)
@@ -442,16 +444,18 @@ mod tests {
 
     script_pubkey.push(opcodes::all::OP_PUSHBYTES_4.to_u8());
 
-    Runestone::decipher(&Transaction {
-      input: Vec::new(),
-      output: vec![TxOut {
-        script_pubkey: ScriptBuf::from_bytes(script_pubkey),
-        value: 0,
-      }],
-      lock_time: LockTime::ZERO,
-      version: 2,
-    })
-    .unwrap_err();
+    assert_eq!(
+      Runestone::payload(&Transaction {
+        input: Vec::new(),
+        output: vec![TxOut {
+          script_pubkey: ScriptBuf::from_bytes(script_pubkey),
+          value: 0,
+        }],
+        lock_time: LockTime::ZERO,
+        version: 2,
+      }),
+      Ok(Some(Payload::Invalid))
+    );
   }
 
   #[test]
@@ -1955,4 +1959,48 @@ mod tests {
       .cenotaph
     );
   }
+
+  #[test]
+  fn invalid_scripts_in_op_returns_are_ignored() {
+    let transaction = Transaction {
+      version: 2,
+      lock_time: LockTime::ZERO,
+      input: vec![TxIn {
+        previous_output: OutPoint::null(),
+        script_sig: ScriptBuf::new(),
+        sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
+        witness: Witness::new(),
+      }],
+      output: vec![TxOut {
+        script_pubkey: ScriptBuf::from(vec![
+          opcodes::all::OP_RETURN.to_u8(),
+          opcodes::all::OP_PUSHBYTES_4.to_u8(),
+        ]),
+        value: 0,
+      }],
+    };
+
+    Runestone::decipher(&transaction).unwrap();
+
+    let transaction = Transaction {
+      version: 2,
+      lock_time: LockTime::ZERO,
+      input: vec![TxIn {
+        previous_output: OutPoint::null(),
+        script_sig: ScriptBuf::new(),
+        sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
+        witness: Witness::new(),
+      }],
+      output: vec![TxOut {
+        script_pubkey: ScriptBuf::from(vec![
+          opcodes::all::OP_RETURN.to_u8(),
+          MAGIC_NUMBER.to_u8(),
+          opcodes::all::OP_PUSHBYTES_4.to_u8(),
+        ]),
+        value: 0,
+      }],
+    };
+
+    Runestone::decipher(&transaction).unwrap();
+  }
 }