Fix data pack biomes failing to load in SingleBiomeProvider (#7434)

src/main/java/net/minecraftforge/common/ForgeHooks.java

@@ -875,13 +875,13 @@ public class ForgeHooks
         Biome apply(final Biome.Climate climate, final Biome.Category category, final Float depth, final Float scale, final BiomeAmbience effects, final BiomeGenerationSettings gen, final MobSpawnInfo spawns);
     }
 
-    public static Biome enhanceBiome(final ResourceLocation name, final Biome.Climate climate, final Biome.Category category, final Float depth, final Float scale, final BiomeAmbience effects, final BiomeGenerationSettings gen, final MobSpawnInfo spawns, final RecordCodecBuilder.Instance<Biome> codec, final BiomeCallbackFunction callback)
+    public static Biome enhanceBiome(@Nullable final ResourceLocation name, final Biome.Climate climate, final Biome.Category category, final Float depth, final Float scale, final BiomeAmbience effects, final BiomeGenerationSettings gen, final MobSpawnInfo spawns, final RecordCodecBuilder.Instance<Biome> codec, final BiomeCallbackFunction callback)
     {
         BiomeGenerationSettingsBuilder genBuilder = new BiomeGenerationSettingsBuilder(gen);
         MobSpawnInfoBuilder spawnBuilder = new MobSpawnInfoBuilder(spawns);
         BiomeLoadingEvent event = new BiomeLoadingEvent(name, climate, category, depth, scale, effects, genBuilder, spawnBuilder);
         MinecraftForge.EVENT_BUS.post(event);
-        return callback.apply(event.getClimate(), event.getCategory(), event.getDepth(), event.getScale(), event.getEffects(), event.getGeneration().func_242508_a(), event.getSpawns().func_242577_b());
+        return callback.apply(event.getClimate(), event.getCategory(), event.getDepth(), event.getScale(), event.getEffects(), event.getGeneration().func_242508_a(), event.getSpawns().func_242577_b()).setRegistryName(name);
     }
 
     private static class LootTableContext

src/main/java/net/minecraftforge/event/world/BiomeLoadingEvent.java

@@ -27,6 +27,8 @@ import net.minecraftforge.common.world.MobSpawnInfoBuilder;
 import net.minecraftforge.eventbus.api.Event;
 import net.minecraftforge.eventbus.api.EventPriority;
 
+import javax.annotation.Nullable;
+
 /**
  * This event fires when a Biome is created from json or when a registered biome is re-created for worldgen.
  * It allows mods to edit a biome (like add a mob spawn) before it gets used for worldgen.
@@ -52,7 +54,7 @@ public class BiomeLoadingEvent extends Event
     private final BiomeGenerationSettingsBuilder gen;
     private final MobSpawnInfoBuilder spawns;
 
-    public BiomeLoadingEvent(final ResourceLocation name, final Biome.Climate climate, final Biome.Category category, final float depth, final float scale, final BiomeAmbience effects, final BiomeGenerationSettingsBuilder gen, final MobSpawnInfoBuilder spawns)
+    public BiomeLoadingEvent(@Nullable final ResourceLocation name, final Biome.Climate climate, final Biome.Category category, final float depth, final float scale, final BiomeAmbience effects, final BiomeGenerationSettingsBuilder gen, final MobSpawnInfoBuilder spawns)
     {
         this.name = name;
         this.climate = climate;
@@ -64,6 +66,12 @@ public class BiomeLoadingEvent extends Event
         this.spawns = spawns;
     }
 
+    /**
+     * This will get the registry name of the biome.
+     * It generally SHOULD NOT be null, but due to vanilla's biome handling and codec weirdness, there may be cases where it is.
+     * Do check for this possibility!
+     */
+    @Nullable
     public ResourceLocation getName()
     {
         return name;