Merge bitcoin/bitcoin#25664: refactor: Redefine `IsSolvable()` using descriptors

b16f93caddcd3254eaf3dc43e09adf2142a9c40a script/sign: remove needless IsSolvable() utility (Antoine Poinsot)
c232ef20c0fd2e3b55355e52684091cad3af5247 outputtype: remove redundant check for uncompressed keys in AddAndGetDestinationForScript (Antoine Poinsot)

Pull request description:

  Now that we have descriptors there is no need to try to sign for a scriptPubKey using dummy signatures, and using a mocked verification of this witness against the interpreter, just to make sure we know how to spend such a Script. Just try to infer a solvable descriptor: any scriptPubKey that we can sign for can be inferred as such.

  This came up in #24149 but i think it's worth it on its own.

ACKs for top commit:
  instagibbs:
    ACK https://github.com/bitcoin/bitcoin/pull/25664/commits/b16f93caddcd3254eaf3dc43e09adf2142a9c40a
  achow101:
    re-ACK b16f93caddcd3254eaf3dc43e09adf2142a9c40a
  furszy:
    ACK b16f93ca, only change is the `IsSolvable` helper function removal.

Tree-SHA512: 137068157ce90210b710b1bf9ac3c400e2ff5af1112f892094b69875ea473d6a899f52adb51e5030cb907dee517602059cd1661107808558efa5de842ba12b41

3 files changed, 1 insertions, 5 deletions

diff --git a/src/test/descriptor_tests.cpp b/src/test/descriptor_tests.cpp
index 8a17472cda..1eb4b373b4 100644
--- a/src/test/descriptor_tests.cpp
+++ b/src/test/descriptor_tests.cpp
@@ -302,7 +302,6 @@ void DoCheck(const std::string& prv, const std::string& pub, const std::string&
             // For each of the produced scripts, verify solvability, and when possible, try to sign a transaction spending it.
             for (size_t n = 0; n < spks.size(); ++n) {
                 BOOST_CHECK_EQUAL(ref[n], HexStr(spks[n]));
-                BOOST_CHECK_EQUAL(IsSolvable(Merge(key_provider, script_provider), spks[n]), (flags & UNSOLVABLE) == 0);
 
                 if (flags & SIGNABLE) {
                     CMutableTransaction spend;
@@ -324,7 +323,7 @@ void DoCheck(const std::string& prv, const std::string& pub, const std::string&
                 BOOST_CHECK(inferred->Expand(0, provider_inferred, spks_inferred, provider_inferred));
                 BOOST_CHECK_EQUAL(spks_inferred.size(), 1U);
                 BOOST_CHECK(spks_inferred[0] == spks[n]);
-                BOOST_CHECK_EQUAL(IsSolvable(provider_inferred, spks_inferred[0]), !(flags & UNSOLVABLE));
+                BOOST_CHECK_EQUAL(InferDescriptor(spks_inferred[0], provider_inferred)->IsSolvable(), !(flags & UNSOLVABLE));
                 BOOST_CHECK(GetKeyOriginData(provider_inferred, flags) == GetKeyOriginData(script_provider, flags));
             }
 
diff --git a/src/test/fuzz/key.cpp b/src/test/fuzz/key.cpp
index 6d2d2e2bc5..a76901e473 100644
--- a/src/test/fuzz/key.cpp
+++ b/src/test/fuzz/key.cpp
@@ -138,8 +138,6 @@ FUZZ_TARGET_INIT(key, initialize_key)
         assert(tx_multisig_script.size() == 37);
 
         FillableSigningProvider fillable_signing_provider;
-        assert(IsSolvable(fillable_signing_provider, tx_pubkey_script));
-        assert(IsSolvable(fillable_signing_provider, tx_multisig_script));
         assert(!IsSegWitOutput(fillable_signing_provider, tx_pubkey_script));
         assert(!IsSegWitOutput(fillable_signing_provider, tx_multisig_script));
         assert(fillable_signing_provider.GetKeys().size() == 0);
diff --git a/src/test/fuzz/script.cpp b/src/test/fuzz/script.cpp
index 69a4b782aa..00d7b7e29a 100644
--- a/src/test/fuzz/script.cpp
+++ b/src/test/fuzz/script.cpp
@@ -89,7 +89,6 @@ FUZZ_TARGET_INIT(script, initialize_script)
     const FlatSigningProvider signing_provider;
     (void)InferDescriptor(script, signing_provider);
     (void)IsSegWitOutput(signing_provider, script);
-    (void)IsSolvable(signing_provider, script);
 
     (void)RecursiveDynamicUsage(script);