Fix extra models registered through ModelLoadingPlugin only loading top level (#4356)

- Adjust testmod to make test extra model have a parent that is not referenced by any other model

Author: PepperCode1

fabric-model-loading-api-v1/src/client/java/net/fabricmc/fabric/mixin/client/model/loading/ReferencedModelsCollectorMixin.java

@@ -26,6 +26,7 @@
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
 
 import net.minecraft.client.render.model.ReferencedModelsCollector;
+import net.minecraft.client.render.model.ResolvableModel;
 import net.minecraft.client.render.model.UnbakedModel;
 import net.minecraft.util.Identifier;
 
@@ -37,6 +38,9 @@ abstract class ReferencedModelsCollectorMixin {
 	@Nullable
 	private ModelLoadingEventDispatcher fabric_eventDispatcher;
 
+	@Shadow
+	public abstract void add(ResolvableModel model);
+
 	@Shadow
 	abstract UnbakedModel computeResolvedModel(Identifier id);
 
@@ -45,7 +49,7 @@ private void onReturnInit(CallbackInfo ci) {
 		fabric_eventDispatcher = ModelLoadingEventDispatcher.CURRENT.get();
 
 		if (fabric_eventDispatcher != null) {
-			fabric_eventDispatcher.forEachExtraModel(this::computeResolvedModel);
+			fabric_eventDispatcher.forEachExtraModel(id -> add(computeResolvedModel(id)));
 		}
 	}
 

fabric-model-loading-api-v1/src/testmodClient/resources/assets/fabric-model-loading-api-v1-testmod/models/half_red_sand.json

@@ -1,21 +1,7 @@
 {
+  "parent": "fabric-model-loading-api-v1-testmod:template_half",
   "textures": {
-    "sand": "minecraft:block/sand",
-    "red_sand": "minecraft:block/red_sand",
-    "particle": "#sand"
-  },
-  "elements": [
-    {
-      "from": [ 0, 0, 0 ],
-      "to": [ 16, 16, 16 ],
-      "faces": {
-        "down": { "texture": "#sand" },
-        "up": { "texture": "#red_sand" },
-        "north": { "texture": "#sand" },
-        "south": { "texture": "#red_sand" },
-        "west": { "texture": "#sand" },
-        "east": { "texture": "#red_sand" }
-      }
-    }
-  ]
+    "half1": "minecraft:block/sand",
+    "half2": "minecraft:block/red_sand"
+  }
 }

fabric-model-loading-api-v1/src/testmodClient/resources/assets/fabric-model-loading-api-v1-testmod/models/template_half.json

@@ -0,0 +1,19 @@
+{
+  "textures": {
+    "particle": "#half1"
+  },
+  "elements": [
+    {
+      "from": [ 0, 0, 0 ],
+      "to": [ 16, 16, 16 ],
+      "faces": {
+        "down": { "texture": "#half1" },
+        "up": { "texture": "#half2" },
+        "north": { "texture": "#half1" },
+        "south": { "texture": "#half2" },
+        "west": { "texture": "#half1" },
+        "east": { "texture": "#half2" }
+      }
+    }
+  ]
+}