Add flag to populate_with_metadata() for unconfirmed tx.

include/bitcoin/database/impl/query/confirmed.ipp

@@ -161,9 +161,15 @@ bool CLASS::is_unconfirmed_spent(const output_link& link) const NOEXCEPT
 TEMPLATE
 bool CLASS::is_spent(const output_link& link) const NOEXCEPT
 {
-    // *Any* tx spends the output. Note that this could even be a tx that is in
+    return is_spent(get_outpoint(link).point());
+}
+
+TEMPLATE
+bool CLASS::is_spent(const point& prevout) const NOEXCEPT
+{
+    // *Any* tx spends the point. Note that this could even be a tx that is in
     // conflict with another long-confirmed tx, or a valid tx in invalid block.
-    return store_.ins.exists(get_outpoint(link).point());
+    return store_.ins.exists(prevout);
 }
 
 } // namespace database

include/bitcoin/database/impl/query/consensus/consensus_populate.ipp

@@ -49,31 +49,31 @@ bool CLASS::populate_with_metadata(const block& block,
 }
 
 TEMPLATE
-bool CLASS::populate_with_metadata(const transaction& tx,
-    bool chain) const NOEXCEPT
+bool CLASS::populate_with_metadata(const transaction& tx, bool chain,
+    bool pool) const NOEXCEPT
 {
     // This override makes the public method safe for coinbase calling.
-    return tx.is_coinbase() || populate_with_metadata_(tx, chain);
+    return tx.is_coinbase() || populate_with_metadata_(tx, chain, pool);
 }
 
 // protected
 TEMPLATE
-bool CLASS::populate_with_metadata_(const transaction& tx,
-    bool chain) const NOEXCEPT
+bool CLASS::populate_with_metadata_(const transaction& tx, bool chain,
+    bool pool) const NOEXCEPT
 {
     BC_ASSERT(!tx.is_coinbase());
 
     const auto& ins = tx.inputs_ptr();
     return std::all_of(ins->begin(), ins->end(),
-        [this, chain](const auto& in) NOEXCEPT
+        [this, chain, pool](const auto& in) NOEXCEPT
         {
-            return this->populate_with_metadata(*in, chain);
+            return this->populate_with_metadata(*in, chain, pool);
         });
 }
 
 TEMPLATE
-bool CLASS::populate_with_metadata(const input& input,
-    bool chain) const NOEXCEPT
+bool CLASS::populate_with_metadata(const input& input, bool chain,
+    bool pool) const NOEXCEPT
 {
     // Null point would return nullptr and be interpreted as missing.
     BC_ASSERT(!input.point().is_null());
@@ -119,7 +119,13 @@ bool CLASS::populate_with_metadata(const input& input,
             metadata.median_time_past = max_uint32;
         }
 
-        if (const auto height = find_strong_spender_height(input.point());
+        if (pool)
+        {
+            // Any spender (including duplicate tx) implies spent.
+            const auto spent = is_spent(input.point());
+            metadata.spender_height = spent ? 0_u32 : max_uint32;
+        }
+        else if (const auto height = find_strong_spender_height(input.point());
             !height.is_terminal())
         {
             // Confirmed spender found at height.

include/bitcoin/database/query.hpp

@@ -468,9 +468,12 @@ class query
     bool populate_without_metadata(const transaction& tx) const NOEXCEPT;
 
     /// False implies missing prevouts, node input.metadata is populated.
-    bool populate_with_metadata(const input& input, bool chain=false) const NOEXCEPT;
+    /// Pool implies free tx, where any conflict implies is spent at height 0.
+    bool populate_with_metadata(const input& input, bool chain=false,
+        bool pool=false) const NOEXCEPT;
     bool populate_with_metadata(const block& block, bool chain=false) const NOEXCEPT;
-    bool populate_with_metadata(const transaction& tx, bool chain=false) const NOEXCEPT;
+    bool populate_with_metadata(const transaction& tx, bool chain=false,
+        bool pool=false) const NOEXCEPT;
 
     /// Fees.
     /// -----------------------------------------------------------------------
@@ -645,6 +648,7 @@ class query
     bool is_unconfirmed_spent(const output_link& link) const NOEXCEPT;
     bool is_confirmed_spent(const output_link& link) const NOEXCEPT;
     bool is_spent(const output_link& link) const NOEXCEPT;
+    bool is_spent(const point& prevout) const NOEXCEPT;
 
     /// Height index not used by these.
     bool is_strong_tx(const tx_link& link) const NOEXCEPT;
@@ -923,8 +927,8 @@ class query
         const header_link& link, size_t height) const NOEXCEPT;
 
     /// Bypasses and only asserts coinbase guard (internal use).
-    bool populate_with_metadata_(const transaction& tx,
-        bool chain) const NOEXCEPT;
+    bool populate_with_metadata_(const transaction& tx, bool chain,
+        bool pool) const NOEXCEPT;
 
     /// merkle
     /// -----------------------------------------------------------------------

test/query/archive/chain_reader.cpp

@@ -852,6 +852,34 @@ BOOST_AUTO_TEST_CASE(query_chain_reader__populate_with_metadata__metadata__expec
     BOOST_CHECK_EQUAL(tx4.inputs_ptr()->at(1)->metadata.parent_tx, 1u);
 }
 
+// A free tx cannot conflict, so any spender of its prevout implies spent.
+BOOST_AUTO_TEST_CASE(query_chain_reader__populate_with_metadata__pool_spender__expected)
+{
+    settings settings{};
+    settings.path = TEST_DIRECTORY;
+    test::chunk_store store{ settings };
+    test::query_accessor query{ store };
+    BOOST_CHECK(!store.create(test::events_handler));
+    BOOST_CHECK(query.initialize(test::genesis));
+    BOOST_CHECK(query.set(test::block1a, test::context, false, false));
+
+    // tx5 spends the first output of the first tx of block1a, as does tx4.
+    const auto& unspent = clean_(test::tx5);
+    BOOST_CHECK(query.populate_with_metadata(unspent, true, true));
+    BOOST_CHECK_EQUAL(unspent.inputs_ptr()->at(0)->metadata.spender_height, max_uint32);
+
+    BOOST_CHECK(query.set(test::tx4));
+
+    const auto& spent = clean_(test::tx5);
+    BOOST_CHECK(query.populate_with_metadata(spent, true, true));
+    BOOST_CHECK_EQUAL(spent.inputs_ptr()->at(0)->metadata.spender_height, 0u);
+
+    // The spender is unassociated, so it is not a confirmed spender.
+    const auto& chained = clean_(test::tx5);
+    BOOST_CHECK(query.populate_with_metadata(chained, true, false));
+    BOOST_CHECK_EQUAL(chained.inputs_ptr()->at(0)->metadata.spender_height, max_uint32);
+}
+
 // populate_without_metadata
 // ----------------------------------------------------------------------------