《泰拉瑞亚》Mechdusa 召唤失败报错且消耗召唤物品

Description​

When attempting to summon Mechdusa without suitable solid blocks nearby, the summon fails because Skeletron Prime cannot find a valid spawn location. However, Mechdusa's spawning routine appears to continue processing the summon, resulting in an invalid NPC array index and the following error:

Code:

Invariant Failed: Error on message 61 @127.0.0.1:56618(Catena). System.IndexOutOfRangeException: Index was outside the bounds of the array.
  at Terraria.NPC.SpawnMechQueen (System.Int32 onWhichPlayer) [0x00091] in <60753b24bd9047648531826bf7e606f0>:0
  at Terraria.MessageBuffer.GetData (System.Int32 start, System.Int32 length, System.Int32& messageType) [0x06422] in <60753b24bd9047648531826bf7e606f0>:0
  at Terraria.NetMessage.CheckBytes (System.Int32 bufferIndex) [0x0011f] in <60753b24bd9047648531826bf7e606f0>:0

The same underlying issue may affect other bosses when their spawn requirements are not met.

Problem​

The main issue is not the error message itself, but the fact that the summoning item is consumed even though the boss never spawns.

For example, attempting to summon Mechdusa without a suitable spawn location consumes the summoning item and plays the summoning sound, but no boss appears. A similar behavior can be reproduced with the Eye of Cthulhu: the summoning sound plays and the item is consumed, but the boss does not spawn.

By contrast, attempting to summon a boss during daytime when it is not allowed to spawn, or attempting to summon a boss that is already alive, does not consume the summoning item.

This suggests that some spawn eligibility checks are performed before the summoning item is consumed, while other failure conditions — such as the inability to find a valid spawn location — are handled too late in the process.

Expected Behavior​

If the game cannot find a valid spawn location, the summoning attempt should fail gracefully without consuming the summoning item.

Suggested Solution​

Validate the spawn conditions before consuming the summoning item or committing to the summoning process. If a valid spawn location cannot be found, cancel the attempt without consuming the item.

Additionally, Mechdusa's spawning routine should handle the failure to spawn Skeletron Prime gracefully and avoid accessing an invalid NPC array index when the initial spawn fails.