Sounds: Partial revert of #14436 and #14341 (#14889)

This reverts functional changes of:
 * commit bf52d1e6 (#14436)
 * commit 63a98538 (#14341)

doc/lua_api.md

@@ -1103,7 +1103,6 @@ Table used to specify how a sound is played:
     -- its end in `-start_time` seconds.
     -- It is unspecified what happens if `loop` is false and `start_time` is
     -- smaller than minus the sound's length.
-
     -- Available since feature `sound_params_start_time`.
 
     loop = false,
@@ -1117,21 +1116,6 @@ Table used to specify how a sound is played:
     -- Attach the sound to an object.
     -- Can't be used together with `pos`.
 
-    -- For backward compatibility, sounds continue playing at the last location
-    -- of the object if an object is removed (for example if an entity dies).
-    -- It is not recommended to rely on this.
-    -- For death sounds, prefer playing a positional sound instead.
-
-    -- If you want to stop a sound when an entity dies or is deactivated,
-    -- store the handle and call `minetest.sound_stop` in `on_die` / `on_deactivate`.
-
-    -- Ephemeral sounds are entirely unaffected by the object being removed
-    -- or leaving the active object range.
-
-    -- Non-ephemeral sounds stop playing on clients if objects leave
-    -- the active object range; they should start playing again if objects
-    --- come back into range (but due to a known bug, they don't yet).
-
     to_player = name,
     -- Only play for this player.
     -- Can't be used together with `exclude_player`.

src/network/clientpackethandler.cpp

@@ -471,6 +471,8 @@ void Client::handleCommand_ActiveObjectRemoveAdd(NetworkPacket* pkt)
 		for (u16 i = 0; i < removed_count; i++) {
 			*pkt >> id;
 			m_env.removeActiveObject(id);
+			// Object-attached sounds MUST NOT be removed here because they might
+			// have started to play immediately before the entity was removed.
 		}
 
 		// Read added objects

src/server.cpp

@@ -2054,19 +2054,10 @@ void Server::SendActiveObjectRemoveAdd(RemoteClient *client, PlayerSAO *playersa
 	// Removed objects
 	pkt << static_cast<u16>(removed_objects.size());
 
-	std::vector<u16> sounds_to_stop;
-
 	for (auto &it : removed_objects) {
 		const auto [gone, id] = it;
 		ServerActiveObject *obj = m_env->getActiveObject(id);
 
-		// Stop sounds if objects go out of range.
-		// This fixes https://github.com/minetest/minetest/issues/8094.
-		// We may not remove sounds if an entity was removed on the server.
-		// See https://github.com/minetest/minetest/issues/14422.
-		if (!gone) // just out of range for client, not gone on server?
-			sounds_to_stop.push_back(id);
-
 		pkt << id;
 
 		// Remove from known objects
@@ -2075,8 +2066,10 @@ void Server::SendActiveObjectRemoveAdd(RemoteClient *client, PlayerSAO *playersa
 			obj->m_known_by_count--;
 	}
 
-	if (!sounds_to_stop.empty())
+	// Note: Do yet NOT stop or remove object-attached sounds where the object goes out
-		stopAttachedSounds(client->peer_id, sounds_to_stop);
+	// of range (client side). Such sounds would need to be re-sent when coming into range.
+	// Currently, the client will initiate m_playing_sounds clean ups indirectly by
+	// "Server::handleCommand_RemovedSounds".
 
 	// Added objects
 	pkt << static_cast<u16>(added_objects.size());
@@ -2260,37 +2253,6 @@ void Server::fadeSound(s32 handle, float step, float gain)
 		m_playing_sounds.erase(it);
 }
 
-void Server::stopAttachedSounds(session_t peer_id,
-	const std::vector<u16> &object_ids)
-{
-	assert(peer_id != PEER_ID_INEXISTENT);
-	assert(!object_ids.empty());
-
-	auto cb = [&] (const s32 id, ServerPlayingSound &sound) -> bool {
-		if (!CONTAINS(object_ids, sound.object))
-			return false;
-
-		auto clients_it = sound.clients.find(peer_id);
-		if (clients_it == sound.clients.end())
-			return false;
-
-		NetworkPacket pkt(TOCLIENT_STOP_SOUND, 4);
-		pkt << id;
-		Send(peer_id, &pkt);
-
-		sound.clients.erase(clients_it);
-		// delete if client list empty
-		return sound.clients.empty();
-	};
-
-	for (auto it = m_playing_sounds.begin(); it != m_playing_sounds.end(); ) {
-		if (cb(it->first, it->second))
-			it = m_playing_sounds.erase(it);
-		else
-			++it;
-	}
-}
-
 void Server::sendRemoveNode(v3s16 p, std::unordered_set<u16> *far_players,
 		float far_d_nodes)
 {

src/server.h

@@ -239,9 +239,6 @@ public:
 	s32 playSound(ServerPlayingSound &params, bool ephemeral=false);
 	void stopSound(s32 handle);
 	void fadeSound(s32 handle, float step, float gain);
-	// Stop all sounds attached to given objects, for a certain client
-	void stopAttachedSounds(session_t peer_id,
-		const std::vector<u16> &object_ids);
 
 	// Envlock
 	std::set<std::string> getPlayerEffectivePrivs(const std::string &name);