Read top links directly from height indexes.

include/bitcoin/node/error.hpp

@@ -123,6 +123,7 @@ enum error_t : uint8_t
     transaction6,
     transaction7,
     transaction8,
+    transaction9,
     estimates_initialize,
     estimates_push1,
     estimates_push2,

src/chasers/chaser_check.cpp

@@ -531,10 +531,10 @@ size_t chaser_check::set_unassociated() NOEXCEPT
     const auto timeout = node_settings().compact_timeout();
     if (!is_zero(timeout.count()) && is_current_chain(false))
     {
-        const auto top = query.get_top_candidate();
-        const auto link = query.to_candidate(top);
+        size_t top{};
+        const auto link = query.to_top_candidate();
         if (link != expired_ && query.is_compact(link) &&
-            !query.is_associated(link))
+            !query.is_associated(link) && query.get_height(top, link))
         {
             stop = std::min(stop, sub1(top));
             if (link != deferred_)

src/chasers/chaser_transaction.cpp

@@ -113,9 +113,16 @@ void chaser_transaction::do_bump() NOEXCEPT
     auto& query = archive();
     if (network_settings().enable_relay)
     {
-        const auto top = query.get_top_confirmed();
+        size_t height{};
+        const auto top = query.to_top_confirmed();
+        if (!query.get_height(height, top))
+        {
+            fault(error::transaction9);
+            return;
+        }
+
         const auto state = query.get_confirmed_chain_state(system_settings(),
-            query.to_confirmed(top), top);
+            top, height);
 
         if (!state)
         {
@@ -135,7 +142,7 @@ void chaser_transaction::do_bump() NOEXCEPT
 
     // A complete map reaches genesis, and keeps up with the top until latched.
     // Rows of a block archived before the latch may precede mapped starts.
-    const auto top = query.to_confirmed(query.get_top_confirmed());
+    const auto top = query.to_top_confirmed();
     const auto unmapped = query.get_scan_start(top).is_terminal();
     if (query.get_scan_start(query.to_confirmed(zero)).is_terminal())
         start_scan(true);
@@ -153,7 +160,7 @@ void chaser_transaction::start_scan(bool remap) NOEXCEPT
     const auto& query = archive();
     const auto bound = query.is_pooling() ? query.get_scan_frontier() :
         max_size_t;
-    const auto top = query.to_confirmed(query.get_top_confirmed());
+    const auto top = query.to_top_confirmed();
     boost::asio::post(scan_threadpool_.service(),
         BIND(do_scan, top, bound, remap));
 }

src/error.cpp

@@ -113,6 +113,7 @@ DEFINE_ERROR_T_MESSAGE_MAP(error)
     { transaction6, "transaction6" },
     { transaction7, "transaction7" },
     { transaction8, "transaction8" },
+    { transaction9, "transaction9" },
     { estimates_initialize, "estimates_initialize" },
     { estimates_push1, "estimates_push1" },
     { estimates_push2, "estimates_push2" },