Handle null/empty sentinel pointers in tx/block subscribers.

Author: evoskuil

src/full_node.cpp

@@ -197,12 +197,15 @@ bool full_node::handle_reorganized(code ec, size_t fork_height,
         return false;
     }
 
+    // Nothing to do here.
+    if (!incoming || incoming->empty())
+        return true;
+
     for (const auto block: *outgoing)
         LOG_DEBUG(LOG_NODE)
             << "Reorganization moved block to orphan pool ["
             << encode_hash(block->header().hash()) << "]";
 
-    BITCOIN_ASSERT(!incoming->empty());
     const auto height = safe_add(fork_height, incoming->size());
 
     set_top_block({ incoming->back()->hash(), height });
@@ -305,7 +308,7 @@ safe_chain& full_node::chain()
 
 void full_node::subscribe_blockchain(reorganize_handler&& handler)
 {
-    chain().subscribe_reorganize(std::move(handler));
+    chain().subscribe_blockchain(std::move(handler));
 }
 
 void full_node::subscribe_transaction(transaction_handler&& handler)

src/protocols/protocol_block_out.cpp

@@ -85,7 +85,7 @@ void protocol_block_out::start()
     SUBSCRIBE2(get_data, handle_receive_get_data, _1, _2);
 
     // Subscribe to block acceptance notifications (the block-out heartbeat).
-    chain_.subscribe_reorganize(BIND4(handle_reorganized, _1, _2, _3, _4));
+    chain_.subscribe_blockchain(BIND4(handle_reorganized, _1, _2, _3, _4));
 }
 
 // Receive send_headers and send_compact.
@@ -437,6 +437,10 @@ bool protocol_block_out::handle_reorganized(code ec, size_t fork_height,
         return false;
     }
 
+    // Nothing to do here.
+    if (!incoming)
+        return true;
+
     // TODO: consider always sending the last block as compact if enabled.
     if (false && compact_to_peer_ && incoming->size() == 1)
     {
@@ -499,6 +503,8 @@ bool protocol_block_out::handle_reorganized(code ec, size_t fork_height,
 
 void protocol_block_out::handle_stop(const code&)
 {
+    chain_.unsubscribe();
+
     LOG_DEBUG(LOG_NETWORK)
         << "Stopped block_out protocol for [" << authority() << "].";
 }

src/protocols/protocol_transaction_out.cpp

@@ -240,6 +240,11 @@ bool protocol_transaction_out::handle_notification(const code& ec,
         return false;
     }
 
+    // TODO: make this a collection and send empty in this case.
+    // Nothing to do, a channel is stopping but it's not this one.
+    if (!message)
+        return true;
+
     if (message->validation.originator == nonce())
         return true;
 
@@ -259,6 +264,8 @@ bool protocol_transaction_out::handle_notification(const code& ec,
 
 void protocol_transaction_out::handle_stop(const code&)
 {
+    chain_.unsubscribe();
+
     LOG_DEBUG(LOG_NETWORK)
         << "Stopped transaction_out protocol for [" << authority() << "].";
 }