[1.14.4] IForgeItem#initCapabilities called before Capabilities are registered

[Choonster]

Minecraft Version: 1.14.4

Forge Version: 28.0.19

Code: https://github.com/Choonster-Minecraft-Mods/TestMod3/tree/ba1306dd180514cc7dd135b21262f8eb72cdd305

Log: https://gist.github.com/Choonster/2ee4d06856ca409f85b89728e9ddd47e

 

After updating to 1.14.4 and attempting to run the client (the first time since updating to 1.14), I encountered a crash due to LastUseTimeModelItem#initCapabilities being called when LastUseTimeCapability.LAST_USE_TIME_CAPABILITY was still null.

 

It appears that an ItemStack of this Item is being created in Minecraft#populateSearchTreeManager, which is called towards the end of Minecraft#init. ClientModLoader.begin is called earlier in Minecraft#init to start loading mods, but this doesn't actually fire FMLCommonSetupEvent (the event that Capabilities are registered in) directly; instead it registers a resource reload listener that fires the event (and the other setup events). The initial reload that calls this listener doesn't happen until the very end of Minecraft#init (after Minecraft#populateSearchTreeManager).

 

It feels counter-intuitive that IForgeItem#initCapabilities can be called before Capabilities have actually been registered, but is this a bug or is it intended behaviour?

Edited July 27, 2019 by Choonster
Formatting

[Draco18s]

Not a currently known issue:

https://github.com/MinecraftForge/MinecraftForge/issues?utf8=✓&q=is%3Aissue+is%3Aopen+capabilities

[Choonster]

I decided to report this on GitHub.

[Choonster]

Lex responded to the issue on GitHub and basically said to register the capabilities earlier and add null protection to the IForgeItem#createProvider implementation:

 

Quote

Register your cap in your constructor and hope it is called before anything anywhere creates a ItemStack.
Since that's not feasible in a multithreaded world, better solution, add null protection to your createProvider code.

 

[Choonster]

It turns out that the constructor of the @Mod class is too early to call CapabilityManager#registerCapability as it uses the CapabilityManager#callbacks map, but this is only initialised between RegistryEvent.NewRegistry and RegistryEvent.Register being fired.

 

Due to this, I kept the capability registration in FMLCommonSetupEvent and just added null protection to the IForgeItem#initCapabilities implementations. This fixed the crash.

 

You can see the changes I made in this commit.