Merge bitcoin/bitcoin#34697: descriptor: fix musig() duplicate key checks and doubled PSBT origin paths

### src/script/descriptor.cpp
@@ -33,6 +33,7 @@
 #include <util/vector.h>
 
 #include <algorithm>
+#include <compare>
 #include <iterator>
 #include <map>
 #include <memory>
@@ -187,18 +188,6 @@ struct PubkeyProvider
 
     virtual ~PubkeyProvider() = default;
 
-    /** Compare two public keys represented by this provider.
-     * Used by the Miniscript descriptors to check for duplicate keys in the script.
-     */
-    bool operator<(PubkeyProvider& other) const {
-        FlatSigningProvider dummy;
-
-        std::optional<CPubKey> a = GetPubKey(0, dummy, dummy);
-        std::optional<CPubKey> b = other.GetPubKey(0, dummy, dummy);
-
-        return a < b;
-    }
-
     /** Derive a public key and put it into out.
      *  read_cache is the cache to read keys from (if not nullptr)
      *  write_cache is the cache to write keys to (if not nullptr)
@@ -278,13 +267,21 @@ class OriginPubkeyProvider final : public PubkeyProvider
     OriginPubkeyProvider(uint32_t exp_index, KeyOriginInfo info, std::unique_ptr<PubkeyProvider> provider, bool apostrophe) : PubkeyProvider(exp_index), m_origin(std::move(info)), m_provider(std::move(provider)), m_apostrophe(apostrophe) {}
     std::optional<CPubKey> GetPubKey(int pos, const SigningProvider& arg, FlatSigningProvider& out, const DescriptorCache* read_cache = nullptr, DescriptorCache* write_cache = nullptr) const override
     {
-        std::optional<CPubKey> pub = m_provider->GetPubKey(pos, arg, out, read_cache, write_cache);
+        // Derive into a temporary provider. Another key expression may have already put this
+        // key into out with its origin prefixed, and prefixing that entry would double it up.
+        FlatSigningProvider subprovider;
+        std::optional<CPubKey> pub = m_provider->GetPubKey(pos, arg, subprovider, read_cache, write_cache);
         if (!pub) return std::nullopt;
-        Assert(out.pubkeys.contains(pub->GetID()));
-        auto& [pubkey, suborigin] = out.origins[pub->GetID()];
+        const CKeyID keyid{pub->GetID()};
+        Assert(subprovider.pubkeys.contains(keyid));
+        auto& [pubkey, suborigin] = subprovider.origins[keyid];
         Assert(pubkey == *pub); // m_provider must have a valid origin by this point.
         suborigin.fingerprint = m_origin.fingerprint;
         suborigin.path.insert(suborigin.path.begin(), m_origin.path.begin(), m_origin.path.end());
+        auto origin{subprovider.origins.extract(keyid)};
+        out.Merge(std::move(subprovider));
+        // An explicit origin takes precedence over an implicit one for the same key.
+        out.origins.insert_or_assign(keyid, std::move(origin.mapped()));
         return pub;
     }
     bool IsRange() const override { return m_provider->IsRange(); }
@@ -2251,7 +2248,19 @@ struct KeyParser {
         : m_out(out), m_in(in), m_script_ctx(ctx), m_expr_index(key_exp_index) {}
 
     bool KeyCompare(const Key& a, const Key& b) const {
-        return *m_keys.at(a).at(0) < *m_keys.at(b).at(0);
+        // Deriving a hardened step needs the private key, so use the provider that was filled
+        // while parsing, or the one we are inferring from, rather than an empty one.
+        const SigningProvider& provider{m_out ? *m_out : (m_in ? *m_in : DUMMY_SIGNING_PROVIDER)};
+        const PubkeyProvider& key_a{*m_keys.at(a).at(0)};
+        const PubkeyProvider& key_b{*m_keys.at(b).at(0)};
+        FlatSigningProvider out_a, out_b;
+        const std::optional<CPubKey> pub_a{key_a.GetPubKey(0, provider, out_a)};
+        const std::optional<CPubKey> pub_b{key_b.GetPubKey(0, provider, out_b)};
+        if (pub_a && pub_b) return *pub_a < *pub_b;
+        // Keys that cannot be derived sort before the ones that can, and are compared by their
+        // expression so that two different keys are not taken for duplicates.
+        if (pub_a.has_value() != pub_b.has_value()) return !pub_a.has_value();
+        return key_a.ToString() < key_b.ToString();
     }
 
     ParseScriptContext ParseContext() const {

### src/test/descriptor_tests.cpp
@@ -1114,6 +1114,10 @@ BOOST_AUTO_TEST_CASE(descriptor_test)
     CheckUnparsable("wsh(or_b(sha256(cdabb7f2dce7bfbd8a0b9570c6fd1e712e5d64045e9d6b517b3d5072251dc204),s:pk(03cdabb7f2dce7bfbd8a0b9570c6fd1e712e5d64045e9d6b517b3d5072251dc204)))", "wsh(or_b(sha256(cdabb7f2dce7bfbd8a0b9570c6fd1e712e5d64045e9d6b517b3d5072251dc204),s:pk(03cdabb7f2dce7bfbd8a0b9570c6fd1e712e5d64045e9d6b517b3d5072251dc204)))", "or_b(sha256(cdabb7f2dce7bfbd8a0b9570c6fd1e712e5d64045e9d6b517b3d5072251dc204),s:pk(03cdabb7f2dce7bfbd8a0b9570c6fd1e712e5d64045e9d6b517b3d5072251dc204)) is not sane: malleable witnesses exist");
     CheckUnparsable("wsh(and_b(and_b(older(1),a:older(100000000)),s:pk(L4gM1FBdyHNpkzsFh9ipnofLhpZRp2mwobpeULy1a6dBTvw8Ywtd)))", "wsh(and_b(and_b(older(1),a:older(100000000)),s:pk(03cdabb7f2dce7bfbd8a0b9570c6fd1e712e5d64045e9d6b517b3d5072251dc204)))", "and_b(older(1),a:older(100000000)) is not sane: contains mixes of timelocks expressed in blocks and seconds");
     CheckUnparsable("wsh(and_b(or_b(pkh(L4gM1FBdyHNpkzsFh9ipnofLhpZRp2mwobpeULy1a6dBTvw8Ywtd),s:pk(Kx9HCDjGiwFcgVNhTrS5z5NeZdD6veeam61eDxLDCkGWujvL4Gnn)),s:pk(L4gM1FBdyHNpkzsFh9ipnofLhpZRp2mwobpeULy1a6dBTvw8Ywtd)))", "wsh(and_b(or_b(pkh(03cdabb7f2dce7bfbd8a0b9570c6fd1e712e5d64045e9d6b517b3d5072251dc204),s:pk(032707170c71d8f75e4ca4e3fce870b9409dcaf12b051d3bcadff74747fa7619c0)),s:pk(03cdabb7f2dce7bfbd8a0b9570c6fd1e712e5d64045e9d6b517b3d5072251dc204)))", "and_b(or_b(pkh(03cdabb7f2dce7bfbd8a0b9570c6fd1e712e5d64045e9d6b517b3d5072251dc204),s:pk(032707170c71d8f75e4ca4e3fce870b9409dcaf12b051d3bcadff74747fa7619c0)),s:pk(03cdabb7f2dce7bfbd8a0b9570c6fd1e712e5d64045e9d6b517b3d5072251dc204)) is not sane: contains duplicate public keys");
+    // Two keys that only differ after a hardened step are not duplicates.
+    Check("wsh(and_v(v:pk(xprv9s21ZrQH143K31xYSDQpPDxsXRTUcvj2iNHm5NUtrGiGG5e2DtALGdso3pGz6ssrdK4PFmM8NSpSBHNqPqm55Qn3LqFtT2emdEXVYsCzC2U/2147483647'/0),pk(xprv9s21ZrQH143K31xYSDQpPDxsXRTUcvj2iNHm5NUtrGiGG5e2DtALGdso3pGz6ssrdK4PFmM8NSpSBHNqPqm55Qn3LqFtT2emdEXVYsCzC2U/2147483647'/1)))", "wsh(and_v(v:pk(xpub661MyMwAqRbcFW31YEwpkMuc5THy2PSt5bDMsktWQcFF8syAmRUapSCGu8ED9W6oDMSgv6Zz8idoc4a6mr8BDzTJY47LJhkJ8UB7WEGuduB/2147483647'/0),pk(xpub661MyMwAqRbcFW31YEwpkMuc5THy2PSt5bDMsktWQcFF8syAmRUapSCGu8ED9W6oDMSgv6Zz8idoc4a6mr8BDzTJY47LJhkJ8UB7WEGuduB/2147483647'/1)))", "wsh(and_v(v:pk([bd16bee5/2147483647h]xpub69H7F5dQzmVd3vPuLKtcXJziMEQByuDidnX3YdwgtNsecY5HRGtAAQC5mXTt4dsv9RzyjgDjAQs9VGVV6ydYCHnprc9vvaA5YtqWyL6hyds/0),pk([bd16bee5/2147483647h]xpub69H7F5dQzmVd3vPuLKtcXJziMEQByuDidnX3YdwgtNsecY5HRGtAAQC5mXTt4dsv9RzyjgDjAQs9VGVV6ydYCHnprc9vvaA5YtqWyL6hyds/1)))", HARDENED, {{"0020cc001315f76b134f2027a7dff589fd9bbdfebc4691a77e0f589fafdadb01f662"}}, OutputType::BECH32, /*op_desc_id=*/std::nullopt, {{0xFFFFFFFFUL, 0}, {0xFFFFFFFFUL, 1}});
+    // But the same key twice is.
+    CheckUnparsable("wsh(and_v(v:pk(xprv9s21ZrQH143K31xYSDQpPDxsXRTUcvj2iNHm5NUtrGiGG5e2DtALGdso3pGz6ssrdK4PFmM8NSpSBHNqPqm55Qn3LqFtT2emdEXVYsCzC2U/2147483647'/0),pk(xprv9s21ZrQH143K31xYSDQpPDxsXRTUcvj2iNHm5NUtrGiGG5e2DtALGdso3pGz6ssrdK4PFmM8NSpSBHNqPqm55Qn3LqFtT2emdEXVYsCzC2U/2147483647'/0)))", "wsh(and_v(v:pk(xpub661MyMwAqRbcFW31YEwpkMuc5THy2PSt5bDMsktWQcFF8syAmRUapSCGu8ED9W6oDMSgv6Zz8idoc4a6mr8BDzTJY47LJhkJ8UB7WEGuduB/2147483647'/0),pk(xpub661MyMwAqRbcFW31YEwpkMuc5THy2PSt5bDMsktWQcFF8syAmRUapSCGu8ED9W6oDMSgv6Zz8idoc4a6mr8BDzTJY47LJhkJ8UB7WEGuduB/2147483647'/0)))", "and_v(v:pk(xpub661MyMwAqRbcFW31YEwpkMuc5THy2PSt5bDMsktWQcFF8syAmRUapSCGu8ED9W6oDMSgv6Zz8idoc4a6mr8BDzTJY47LJhkJ8UB7WEGuduB/2147483647'/0),pk(xpub661MyMwAqRbcFW31YEwpkMuc5THy2PSt5bDMsktWQcFF8syAmRUapSCGu8ED9W6oDMSgv6Zz8idoc4a6mr8BDzTJY47LJhkJ8UB7WEGuduB/2147483647'/0)) is not sane: contains duplicate public keys");
     // Valid with extended keys.
     Check("wsh(and_v(v:ripemd160(095ff41131e5946f3c85f79e44adbcf8e27e080e),multi(1,xprvA1RpRA33e1JQ7ifknakTFpgNXPmW2YvmhqLQYMmrj4xJXXWYpDPS3xz7iAxn8L39njGVyuoseXzU6rcxFLJ8HFsTjSyQbLYnMpCqE2VbFWc,xprv9uPDJpEQgRQfDcW7BkF7eTya6RPxXeJCqCJGHuCJ4GiRVLzkTXBAJMu2qaMWPrS7AANYqdq6vcBcBUdJCVVFceUvJFjaPdGZ2y9WACViL4L/0)))", "wsh(and_v(v:ripemd160(095ff41131e5946f3c85f79e44adbcf8e27e080e),multi(1,xpub6ERApfZwUNrhLCkDtcHTcxd75RbzS1ed54G1LkBUHQVHQKqhMkhgbmJbZRkrgZw4koxb5JaHWkY4ALHY2grBGRjaDMzQLcgJvLJuZZvRcEL,xpub68NZiKmJWnxxS6aaHmn81bvJeTESw724CRDs6HbuccFQN9Ku14VQrADWgqbhhTHBaohPX4CjNLf9fq9MYo6oDaPPLPxSb7gwQN3ih19Zm4Y/0)))", "wsh(and_v(v:ripemd160(095ff41131e5946f3c85f79e44adbcf8e27e080e),multi(1,xpub6ERApfZwUNrhLCkDtcHTcxd75RbzS1ed54G1LkBUHQVHQKqhMkhgbmJbZRkrgZw4koxb5JaHWkY4ALHY2grBGRjaDMzQLcgJvLJuZZvRcEL,xpub68NZiKmJWnxxS6aaHmn81bvJeTESw724CRDs6HbuccFQN9Ku14VQrADWgqbhhTHBaohPX4CjNLf9fq9MYo6oDaPPLPxSb7gwQN3ih19Zm4Y/0)))", DEFAULT, {{"0020acf425291b98a1d7e0d4690139442abc289175be32ef1f75945e339924246d73"}}, OutputType::BECH32, /*op_desc_id=*/uint256{"0634b326edc66f9e2660562564d7a8fcca55f91dc4555ce0a51883cc72e0fa41"}, {{},{0}});
     // Valid under sh(wsh()) and with a mix of xpubs and raw keys.
@@ -1176,6 +1180,14 @@ BOOST_AUTO_TEST_CASE(descriptor_test)
     Check("tr(KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qYjgd9M7rFU74sHUHy8S,pk(musig(xprvA1RpRA33e1JQ7ifknakTFpgNXPmW2YvmhqLQYMmrj4xJXXWYpDPS3xz7iAxn8L39njGVyuoseXzU6rcxFLJ8HFsTjSyQbLYnMpCqE2VbFWc,xpub68NZiKmJWnxxS6aaHmn81bvJeTESw724CRDs6HbuccFQN9Ku14VQrADWgqbhhTHBaohPX4CjNLf9fq9MYo6oDaPPLPxSb7gwQN3ih19Zm4Y)/0/*))","tr(f9308a019258c31049344f85f89d5229b531c845836f99b08601f113bce036f9,pk(musig(xpub6ERApfZwUNrhLCkDtcHTcxd75RbzS1ed54G1LkBUHQVHQKqhMkhgbmJbZRkrgZw4koxb5JaHWkY4ALHY2grBGRjaDMzQLcgJvLJuZZvRcEL,xpub68NZiKmJWnxxS6aaHmn81bvJeTESw724CRDs6HbuccFQN9Ku14VQrADWgqbhhTHBaohPX4CjNLf9fq9MYo6oDaPPLPxSb7gwQN3ih19Zm4Y)/0/*))","tr(f9308a019258c31049344f85f89d5229b531c845836f99b08601f113bce036f9,pk(musig(xpub6ERApfZwUNrhLCkDtcHTcxd75RbzS1ed54G1LkBUHQVHQKqhMkhgbmJbZRkrgZw4koxb5JaHWkY4ALHY2grBGRjaDMzQLcgJvLJuZZvRcEL,xpub68NZiKmJWnxxS6aaHmn81bvJeTESw724CRDs6HbuccFQN9Ku14VQrADWgqbhhTHBaohPX4CjNLf9fq9MYo6oDaPPLPxSb7gwQN3ih19Zm4Y)/0/*))", MISSING_PRIVKEYS | XONLY_KEYS | RANGE | MUSIG | MUSIG_DERIVATION, {{"512068983d461174afc90c26f3b2821d8a9ced9534586a756763b68371a404635cc8"}, {"5120368e2d864115181bdc8bb5dc8684be8d0760d5c33315570d71a21afce4afd43e"}, {"512097a1e6270b33ad85744677418bae5f59ea9136027223bc6e282c47c167b471d5"}}, OutputType::BECH32M, /*op_desc_id=*/std::nullopt, {{}, {0, 0}, {0, 1}, {0, 2}});
     Check("tr(musig(xprvA1RpRA33e1JQ7ifknakTFpgNXPmW2YvmhqLQYMmrj4xJXXWYpDPS3xz7iAxn8L39njGVyuoseXzU6rcxFLJ8HFsTjSyQbLYnMpCqE2VbFWc/1,xprvA1RpRA33e1JQ7ifknakTFpgNXPmW2YvmhqLQYMmrj4xJXXWYpDPS3xz7iAxn8L39njGVyuoseXzU6rcxFLJ8HFsTjSyQbLYnMpCqE2VbFWc/1)/2)", "tr(musig(xpub6ERApfZwUNrhLCkDtcHTcxd75RbzS1ed54G1LkBUHQVHQKqhMkhgbmJbZRkrgZw4koxb5JaHWkY4ALHY2grBGRjaDMzQLcgJvLJuZZvRcEL/1,xpub6ERApfZwUNrhLCkDtcHTcxd75RbzS1ed54G1LkBUHQVHQKqhMkhgbmJbZRkrgZw4koxb5JaHWkY4ALHY2grBGRjaDMzQLcgJvLJuZZvRcEL/1)/2)", "tr(musig(xpub6ERApfZwUNrhLCkDtcHTcxd75RbzS1ed54G1LkBUHQVHQKqhMkhgbmJbZRkrgZw4koxb5JaHWkY4ALHY2grBGRjaDMzQLcgJvLJuZZvRcEL/1,xpub6ERApfZwUNrhLCkDtcHTcxd75RbzS1ed54G1LkBUHQVHQKqhMkhgbmJbZRkrgZw4koxb5JaHWkY4ALHY2grBGRjaDMzQLcgJvLJuZZvRcEL/1)/2)", XONLY_KEYS | MUSIG | MUSIG_DERIVATION | UNIQUE_XPUBS, {{"5120a17ceacd6422bd5ffd9f165807b254b7d68ad39f179cc4f11545a6835227e97c"}}, OutputType::BECH32M, /*op_desc_id=*/std::nullopt, {{1}, {2}});
     Check("rawtr(musig(xprv9s21ZrQH143K31xYSDQpPDxsXRTUcvj2iNHm5NUtrGiGG5e2DtALGdso3pGz6ssrdK4PFmM8NSpSBHNqPqm55Qn3LqFtT2emdEXVYsCzC2U/2147483647'/0,xpub68NZiKmJWnxxS6aaHmn81bvJeTESw724CRDs6HbuccFQN9Ku14VQrADWgqbhhTHBaohPX4CjNLf9fq9MYo6oDaPPLPxSb7gwQN3ih19Zm4Y)/1)","rawtr(musig(xpub661MyMwAqRbcFW31YEwpkMuc5THy2PSt5bDMsktWQcFF8syAmRUapSCGu8ED9W6oDMSgv6Zz8idoc4a6mr8BDzTJY47LJhkJ8UB7WEGuduB/2147483647'/0,xpub68NZiKmJWnxxS6aaHmn81bvJeTESw724CRDs6HbuccFQN9Ku14VQrADWgqbhhTHBaohPX4CjNLf9fq9MYo6oDaPPLPxSb7gwQN3ih19Zm4Y)/1)","rawtr(musig([bd16bee5/2147483647h]xpub69H7F5dQzmVd3vPuLKtcXJziMEQByuDidnX3YdwgtNsecY5HRGtAAQC5mXTt4dsv9RzyjgDjAQs9VGVV6ydYCHnprc9vvaA5YtqWyL6hyds/0,xpub68NZiKmJWnxxS6aaHmn81bvJeTESw724CRDs6HbuccFQN9Ku14VQrADWgqbhhTHBaohPX4CjNLf9fq9MYo6oDaPPLPxSb7gwQN3ih19Zm4Y)/1)", MISSING_PRIVKEYS | HARDENED | XONLY_KEYS | MUSIG | MUSIG_DERIVATION, {{"5120ebf2bcce516ef6567a9001ce6e5dc43a02bb62d37b51d86d773fa96dcd3a8d4c"}}, OutputType::BECH32M, /*op_desc_id=*/std::nullopt, {{}, {0xFFFFFFFFUL,0}, {1}});
+    // A musig() with a hardened participant and a key on a hardened path are not duplicates
+    // just because neither of them can be derived without the private keys.
+    Check("tr(KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qYjgd9M7rFU74sHUHy8S,and_v(v:pk(musig(xprv9s21ZrQH143K31xYSDQpPDxsXRTUcvj2iNHm5NUtrGiGG5e2DtALGdso3pGz6ssrdK4PFmM8NSpSBHNqPqm55Qn3LqFtT2emdEXVYsCzC2U/2147483647',xpub68NZiKmJWnxxS6aaHmn81bvJeTESw724CRDs6HbuccFQN9Ku14VQrADWgqbhhTHBaohPX4CjNLf9fq9MYo6oDaPPLPxSb7gwQN3ih19Zm4Y)/0/*),pk(xprvA1RpRA33e1JQ7ifknakTFpgNXPmW2YvmhqLQYMmrj4xJXXWYpDPS3xz7iAxn8L39njGVyuoseXzU6rcxFLJ8HFsTjSyQbLYnMpCqE2VbFWc/2147483647'/*)))", "tr(f9308a019258c31049344f85f89d5229b531c845836f99b08601f113bce036f9,and_v(v:pk(musig(xpub661MyMwAqRbcFW31YEwpkMuc5THy2PSt5bDMsktWQcFF8syAmRUapSCGu8ED9W6oDMSgv6Zz8idoc4a6mr8BDzTJY47LJhkJ8UB7WEGuduB/2147483647',xpub68NZiKmJWnxxS6aaHmn81bvJeTESw724CRDs6HbuccFQN9Ku14VQrADWgqbhhTHBaohPX4CjNLf9fq9MYo6oDaPPLPxSb7gwQN3ih19Zm4Y)/0/*),pk(xpub6ERApfZwUNrhLCkDtcHTcxd75RbzS1ed54G1LkBUHQVHQKqhMkhgbmJbZRkrgZw4koxb5JaHWkY4ALHY2grBGRjaDMzQLcgJvLJuZZvRcEL/2147483647'/*)))", "tr(f9308a019258c31049344f85f89d5229b531c845836f99b08601f113bce036f9,and_v(v:pk(musig([bd16bee5/2147483647h]xpub69H7F5dQzmVd3vPuLKtcXJziMEQByuDidnX3YdwgtNsecY5HRGtAAQC5mXTt4dsv9RzyjgDjAQs9VGVV6ydYCHnprc9vvaA5YtqWyL6hyds,xpub68NZiKmJWnxxS6aaHmn81bvJeTESw724CRDs6HbuccFQN9Ku14VQrADWgqbhhTHBaohPX4CjNLf9fq9MYo6oDaPPLPxSb7gwQN3ih19Zm4Y)/0/*),pk([31a507b8/2147483647h]xpub6FnCn6njftEsJk8fVPgMd9wrx9V8kbev3sQd1aQKHhUqY5es9yhtRWZBTb6YxtxVCZZYBoFWSEGDDD9m6hFCSZEyzr1e7NGixS6iTZ4jTJq/*)))", MISSING_PRIVKEYS | HARDENED | XONLY_KEYS | RANGE | MUSIG | MUSIG_DERIVATION | MIXED_MUSIG, {{"51209e6f89f5d818d823b2d6f5369da1622e9c5886733e496ae1f8dedbd7cb7e75f8"}, {"5120a9cd4ed7371eda00f4e9a7f72ba9b7eacac03e4bae45799eaa443dba0e2a23cb"}, {"5120a0b097ec0957a48ad2cc6fb214abdb63c35674abed9b6d10349721ffd004578f"}}, OutputType::BECH32M, /*op_desc_id=*/std::nullopt, {{}, {0xFFFFFFFFUL}, {0, 0}, {0, 1}, {0, 2}, {0xFFFFFFFFUL, 0}, {0xFFFFFFFFUL, 1}, {0xFFFFFFFFUL, 2}});
+    // The origin of a participant that is expanded more than once only gets prepended once.
+    Check("tr(musig([0f056943/86h/1h/0h]xprvA1RpRA33e1JQ7ifknakTFpgNXPmW2YvmhqLQYMmrj4xJXXWYpDPS3xz7iAxn8L39njGVyuoseXzU6rcxFLJ8HFsTjSyQbLYnMpCqE2VbFWc/1,[0f056943/86h/1h/0h]xprvA1RpRA33e1JQ7ifknakTFpgNXPmW2YvmhqLQYMmrj4xJXXWYpDPS3xz7iAxn8L39njGVyuoseXzU6rcxFLJ8HFsTjSyQbLYnMpCqE2VbFWc/1)/2)", "tr(musig([0f056943/86h/1h/0h]xpub6ERApfZwUNrhLCkDtcHTcxd75RbzS1ed54G1LkBUHQVHQKqhMkhgbmJbZRkrgZw4koxb5JaHWkY4ALHY2grBGRjaDMzQLcgJvLJuZZvRcEL/1,[0f056943/86h/1h/0h]xpub6ERApfZwUNrhLCkDtcHTcxd75RbzS1ed54G1LkBUHQVHQKqhMkhgbmJbZRkrgZw4koxb5JaHWkY4ALHY2grBGRjaDMzQLcgJvLJuZZvRcEL/1)/2)", "tr(musig([0f056943/86h/1h/0h]xpub6ERApfZwUNrhLCkDtcHTcxd75RbzS1ed54G1LkBUHQVHQKqhMkhgbmJbZRkrgZw4koxb5JaHWkY4ALHY2grBGRjaDMzQLcgJvLJuZZvRcEL/1,[0f056943/86h/1h/0h]xpub6ERApfZwUNrhLCkDtcHTcxd75RbzS1ed54G1LkBUHQVHQKqhMkhgbmJbZRkrgZw4koxb5JaHWkY4ALHY2grBGRjaDMzQLcgJvLJuZZvRcEL/1)/2)", XONLY_KEYS | MUSIG | MUSIG_DERIVATION | UNIQUE_XPUBS, {{"5120a17ceacd6422bd5ffd9f165807b254b7d68ad39f179cc4f11545a6835227e97c"}}, OutputType::BECH32M, /*op_desc_id=*/std::nullopt, {{86 | 0x80000000UL, 1 | 0x80000000UL, 0 | 0x80000000UL, 1}, {2}});
+    // An explicit origin replaces the implicit origin from an earlier expression.
+    const std::string mixed_origin_pub{"tr(musig(xpub6ERApfZwUNrhLCkDtcHTcxd75RbzS1ed54G1LkBUHQVHQKqhMkhgbmJbZRkrgZw4koxb5JaHWkY4ALHY2grBGRjaDMzQLcgJvLJuZZvRcEL/1,[0f056943/86h]xpub6ERApfZwUNrhLCkDtcHTcxd75RbzS1ed54G1LkBUHQVHQKqhMkhgbmJbZRkrgZw4koxb5JaHWkY4ALHY2grBGRjaDMzQLcgJvLJuZZvRcEL/1)/2)"};
+    Check("tr(musig(xprvA1RpRA33e1JQ7ifknakTFpgNXPmW2YvmhqLQYMmrj4xJXXWYpDPS3xz7iAxn8L39njGVyuoseXzU6rcxFLJ8HFsTjSyQbLYnMpCqE2VbFWc/1,[0f056943/86h]xprvA1RpRA33e1JQ7ifknakTFpgNXPmW2YvmhqLQYMmrj4xJXXWYpDPS3xz7iAxn8L39njGVyuoseXzU6rcxFLJ8HFsTjSyQbLYnMpCqE2VbFWc/1)/2)", mixed_origin_pub, mixed_origin_pub, XONLY_KEYS | MUSIG | MUSIG_DERIVATION | UNIQUE_XPUBS, {{"5120a17ceacd6422bd5ffd9f165807b254b7d68ad39f179cc4f11545a6835227e97c"}}, OutputType::BECH32M, /*op_desc_id=*/std::nullopt, {{86 | 0x80000000UL, 1}, {2}});
     CheckMultipath("rawtr(musig(xprvA1RpRA33e1JQ7ifknakTFpgNXPmW2YvmhqLQYMmrj4xJXXWYpDPS3xz7iAxn8L39njGVyuoseXzU6rcxFLJ8HFsTjSyQbLYnMpCqE2VbFWc/<1;2;3>/0/*,xprv9uPDJpEQgRQfDcW7BkF7eTya6RPxXeJCqCJGHuCJ4GiRVLzkTXBAJMu2qaMWPrS7AANYqdq6vcBcBUdJCVVFceUvJFjaPdGZ2y9WACViL4L/0/*,xprv9s21ZrQH143K3jUwNHoqQNrtzJnJmx4Yup8NkNLdVQCymYbPbJXnPhwkfTfxZfptcs3rLAPUXS39oDLgrNKQGwbGsEmJJ8BU3RzQuvShEG4/0/0/<3;4;5>/*))",
             "rawtr(musig(xpub6ERApfZwUNrhLCkDtcHTcxd75RbzS1ed54G1LkBUHQVHQKqhMkhgbmJbZRkrgZw4koxb5JaHWkY4ALHY2grBGRjaDMzQLcgJvLJuZZvRcEL/<1;2;3>/0/*,xpub68NZiKmJWnxxS6aaHmn81bvJeTESw724CRDs6HbuccFQN9Ku14VQrADWgqbhhTHBaohPX4CjNLf9fq9MYo6oDaPPLPxSb7gwQN3ih19Zm4Y/0/*,xpub661MyMwAqRbcGDZQUKLqmWodYLcoBQnQH33yYkkF3jjxeLvY8qr2wWGEWkiKFaaQfJCoi3HeEq3Dc5DptfbCyjD38fNhSqtKc1UHaP4ba3t/0/0/<3;4;5>/*))",
             {

### test/functional/wallet_musig.py
@@ -202,6 +202,9 @@ def test_success_case(self, comment, pattern, sighash_type=None, scriptpath=Fals
         wallets, keys = self.create_wallets_and_keys_from_pattern(pat)
         self.construct_and_import_musig_descriptor_in_wallets(pat, wallets, keys, only_one_musig_wallet)
 
+        # The participant maps are keyed by the aggregate pubkey, which does not depend on the
+        # order of the participants nor on the derivation applied to the aggregate.
+        expected_participant_maps = len({tuple(sorted(musig.split(","))) for musig in MUSIG_RE.findall(pat)})
         expected_pubnonces = 0
         expected_partial_sigs = 0
         for musig in MUSIG_RE.findall(pat):
@@ -252,24 +255,29 @@ def test_success_case(self, comment, pattern, sighash_type=None, scriptpath=Fals
 
         dec_psbt = self.nodes[0].decodepsbt(psbt)
         assert_equal(len(dec_psbt["inputs"]), 1)
-        assert_equal(len(dec_psbt["inputs"][0]["musig2_participant_pubkeys"]), pattern.count("musig("))
+        assert_equal(len(dec_psbt["inputs"][0]["musig2_participant_pubkeys"]), expected_participant_maps)
         if has_internal:
-            assert_equal(len(dec_psbt["outputs"][1]["musig2_participant_pubkeys"]), pattern.count("musig("))
+            assert_equal(len(dec_psbt["outputs"][1]["musig2_participant_pubkeys"]), expected_participant_maps)
 
         # Check all participant pubkeys in the input and change output
         psbt_maps = [dec_psbt["inputs"][0]]
         if has_internal:
             psbt_maps.append(dec_psbt["outputs"][1])
+        origin_paths = {ORIGIN_PATH_RE.search(pub).group(1) for _, pub in keys}
         for psbt_map in psbt_maps:
             part_pks = set()
             for agg in psbt_map["musig2_participant_pubkeys"]:
                 for part_pub in agg["participant_pubkeys"]:
                     part_pks.add(part_pub[2:])
             # Check that there are as many participants as we expected
             assert_equal(len(part_pks), len(keys))
-            # Check that each participant has a derivation path
+            # Check that each participant has a derivation path, and that its origin appears in
+            # that path just once no matter how many musig() expressions the participant is in
             for deriv_path in psbt_map["taproot_bip32_derivs"]:
                 if deriv_path["pubkey"] in part_pks:
+                    origin = next((o for o in origin_paths if deriv_path["path"].startswith(f"m{o}")), None)
+                    assert origin is not None, deriv_path["path"]
+                    assert_equal(deriv_path["path"].count(origin), 1)
                     part_pks.remove(deriv_path["pubkey"])
             assert_equal(len(part_pks), 0)
 
@@ -346,6 +354,7 @@ def run_test(self):
         self.test_success_case("tr(H,pk(musig/*))", "tr($H,pk(musig($0,$1,$2)/<0;1>/*))", scriptpath=True)
         self.test_success_case("tr(H,{pk(musig/*), pk(musig/*)})", "tr($H,{pk(musig($0,$1,$2)/<0;1>/*),pk(musig($3,$4,$5)/0/*)})", scriptpath=True)
         self.test_success_case("tr(H,{pk(musig/*), pk(same keys different musig/*)})", "tr($H,{pk(musig($0,$1,$2)/<0;1>/*),pk(musig($1,$2)/0/*)})", scriptpath=True)
+        self.test_success_case("tr(H,and(pk(musig/*),pk(same musig, other derivation/*)))", "tr($H,and_v(v:pk(musig($0,$1,$2)/<0;1>/*),pk(musig($0,$1,$2)/<2;3>/*)))", scriptpath=True)
         self.test_success_case("tr(musig/*,{pk(partial keys diff musig-1/*),pk(partial keys diff musig-2/*)})}", "tr(musig($0,$1,$2)/<3;4>/*,{pk(musig($0,$1)/<5;6>/*),pk(musig($1,$2)/7/*)})")
         self.test_success_case("tr(musig/*,{pk(partial keys diff musig-1/*),pk(partial keys diff musig-2/*)})} script-path", "tr(musig($0,$1,$2)/<3;4>/*,{pk(musig($0,$1)/<5;6>/*),pk(musig($1,$2)/7/*)})", scriptpath=True, nosign_wallets=[0])
         self.test_success_case("tr(H,and(pk(musig/*),after(1)))", "tr($H,and_v(v:pk(musig($0,$1,$2)/<0;1>/*),after(1)))", scriptpath=True)