Minecraft 1.17.1, Forge 37.0.2
I'm developing a custom language provider for Scala. I created the jar as the same way as 1.16.5, but Minecraft crashes with this error.
NPE happens in the call of SecureJar#name, which calls JarMetadata#name.
The default lang loaders(javafml, mclangage, etc.) is provided with SimpleJarMetadata or ModuleJarMetadata, where JarMetadata#name must return valid value.
But jars in mods dir have ModJarMetadata. In the class, JarMetadata#name fails if modFile.getModFileInfo() is null. For mod jar(FMLModType is MOD), the field(modFile.modFileInfo) is set in construction but for LANGPROVIDER the field remains null.
What I did
Created a class that implements `IModLanguageProvider`
Made a service provider file at META-INF/services/net.minecraftforge.forgespi.language.IModLanguageProvider
It contains the class name that implements `net.minecraftforge.forgespi.language.IModLanguageProvider`
Created other classes such as Mod Container, Language Target.
Then, I made a jar file.
Content of MANIFEST.MF in jar. I know "Main-Class" is not needed for Minecraft. It's for my test. I think "FMLModType" must be "LANGPROVIDER" if I want to create language provider, as the same way in 1.16.5.
EDIT: The PR https://github.com/MinecraftForge/MinecraftForge/pull/7947 will solve this problem.
