FIx equal verify bugs

And other bugs

Author: sanket1729

src/miniscript/astelem.rs

@@ -701,8 +701,8 @@ impl<Pk: MiniscriptKey, Ctx: ScriptContext> Terminal<Pk, Ctx> {
                 .push_opcode(opcodes::all::OP_EQUAL),
             Terminal::True => builder.push_opcode(opcodes::OP_TRUE),
             Terminal::False => builder.push_opcode(opcodes::OP_FALSE),
-            Terminal::Version(n) => builder.check_item_eq(11, &serialize(&n)),
-            Terminal::OutputsPref(ref pref) => builder.check_item_pref(3, pref),
+            Terminal::Version(n) => builder.check_item_eq(1, &serialize(&n)),
+            Terminal::OutputsPref(ref pref) => builder.check_item_pref(9, pref),
             Terminal::Alt(ref sub) => builder
                 .push_opcode(opcodes::all::OP_TOALTSTACK)
                 .push_astelem(sub)

src/miniscript/decode.rs

@@ -282,6 +282,31 @@ pub fn parse<Ctx: ScriptContext>(
                                     ))?
                                 },
                             ),
+                            Tk::Push4(ver), Tk::Pick, Tk::Sub, Tk::Depth => match_token!(
+                                tokens,
+                                Tk::Num(2) => {
+                                    non_term.push(NonTerm::Verify);
+                                    term.reduce0(Terminal::Version(ver))?
+                                },
+                            ),
+                            Tk::Pick, Tk::Sub, Tk::Depth => match_token!(
+                                tokens,
+                                Tk::Num(10) => match_token!(
+                                    tokens,
+                                    Tk::Hash256, Tk::Cat, Tk::Swap, Tk::Push(bytes), Tk::Cat, Tk::Cat, Tk::Cat, Tk::Cat, Tk::Cat =>
+                                        {
+                                            non_term.push(NonTerm::Verify);
+                                            term.reduce0(Terminal::OutputsPref(bytes))?
+                                        },
+                                ),
+                            ),
+                            Tk::Num(k) => {
+                                non_term.push(NonTerm::Verify);
+                                non_term.push(NonTerm::ThreshW {
+                                    k: k as usize,
+                                    n: 0
+                                });
+                            },
                         ),
                         x => {
                             tokens.un_next(x);
@@ -337,13 +362,13 @@ pub fn parse<Ctx: ScriptContext>(
                         ),
                         Tk::Push4(ver), Tk::Pick, Tk::Sub, Tk::Depth => match_token!(
                             tokens,
-                            Tk::Num(12) => term.reduce0(Terminal::Version(ver))?,
+                            Tk::Num(2) => term.reduce0(Terminal::Version(ver))?,
                         ),
                         Tk::Pick, Tk::Sub, Tk::Depth => match_token!(
                             tokens,
-                            Tk::Num(3) => match_token!(
+                            Tk::Num(10) => match_token!(
                                 tokens,
-                                Tk::Hash256, Tk::Cat, Tk::Swap, Tk::PushPrefCat(bytes), Tk::Cat, Tk::Cat, Tk::Cat, Tk::Cat, Tk::Cat =>
+                                Tk::Hash256, Tk::Cat, Tk::Swap, Tk::Push(bytes), Tk::Cat, Tk::Cat, Tk::Cat, Tk::Cat, Tk::Cat =>
                                     term.reduce0(Terminal::OutputsPref(bytes))?,
                             ),
                         ),

src/miniscript/lex.rs

@@ -66,7 +66,7 @@ pub enum Token {
     Hash32([u8; 32]),
     Pubkey(PublicKey),
     Push4(u32),
-    PushPrefCat(Vec<u8>), // <pref> <swap> <cat> /* prefix is catted */
+    Push(Vec<u8>), // <pref> <swap> <cat> /* prefix is catted */
 }
 
 impl fmt::Display for Token {
@@ -253,12 +253,15 @@ pub fn lex(script: &script::Script) -> Result<Vec<Token>, Error> {
                 ret.push(Token::Hash256);
             }
             script::Instruction::PushBytes(bytes) => {
-                // Check for PushPrefCat
+                // Check for Push
                 let ret_len = ret.len();
-                if ret.last() == Some(&Token::Swap) && ret.get(ret_len - 2) == Some(&Token::Cat) {
-                    ret.pop().unwrap();
-                    ret.pop().unwrap();
-                    ret.push(Token::PushPrefCat(bytes.to_owned()));
+                // See that last five elements are CAT
+                // Checking only two here
+                if ret_len >= 5
+                    && ret.last() == Some(&Token::Cat)
+                    && ret.get(ret_len - 2) == Some(&Token::Cat)
+                {
+                    ret.push(Token::Push(bytes.to_owned()));
                 }
                 // Special handling of tokens for Covenants
                 // To determine whether some Token is actually

src/miniscript/mod.rs

@@ -653,6 +653,10 @@ mod tests {
             &ms_str!("tv:1"),
             "Script(OP_PUSHNUM_1 OP_VERIFY OP_PUSHNUM_1)",
         );
+        roundtrip(
+            &ms_str!("tv:thresh(1,pk(02d7924d4f7d43ea965a465ae3095ff41131e5946f3c85f79e44adbcf8e27e080e))", ),
+            "Script(OP_PUSHBYTES_33 02d7924d4f7d43ea965a465ae3095ff41131e5946f3c85f79e44adbcf8e27e080e OP_CHECKSIG OP_PUSHNUM_1 OP_EQUALVERIFY OP_PUSHNUM_1)",
+        );
         roundtrip(&ms_str!("0"), "Script(OP_0)");
         roundtrip(
             &ms_str!("andor(0,1,0)"),
@@ -867,6 +871,12 @@ mod tests {
              OP_PUSHNUM_1\
              )"
         );
+
+        // Thresh bug with equal verify roundtrip
+        roundtrip(
+            &ms_str!("tv:thresh(1,pk(02d7924d4f7d43ea965a465ae3095ff41131e5946f3c85f79e44adbcf8e27e080e))", ),
+               "Script(OP_PUSHBYTES_33 02d7924d4f7d43ea965a465ae3095ff41131e5946f3c85f79e44adbcf8e27e080e OP_CHECKSIG OP_PUSHNUM_1 OP_EQUALVERIFY OP_PUSHNUM_1)",
+        );
     }
 
     #[test]
@@ -896,7 +906,7 @@ mod tests {
     fn cov_script_rtt() {
         roundtrip(
             &ms_str!("ver_eq(4)"),
-            "Script(OP_PUSHNUM_12 OP_DEPTH OP_SUB OP_PICK OP_PUSHBYTES_4 04000000 OP_EQUAL)",
+            "Script(OP_PUSHNUM_2 OP_DEPTH OP_SUB OP_PICK OP_PUSHBYTES_4 04000000 OP_EQUAL)",
         );
     }
 }