Default bucket model is empty, allow bucket model without fluid.

This allows capsules, cans, bottles,... to use the same item model for their item variant. Also it's makes much more sense.

src/main/java/net/minecraftforge/client/model/ModelDynBucket.java

@@ -48,7 +48,7 @@ public class ModelDynBucket implements IModel, IModelCustomData, IRetexturableMo
 
     public ModelDynBucket()
     {
-        this(null, null, null, FluidRegistry.WATER, false);
+        this(null, null, null, null, false);
     }
 
     public ModelDynBucket(ResourceLocation baseLocation, ResourceLocation liquidLocation, ResourceLocation coverLocation, Fluid fluid, boolean flipGas)
@@ -88,22 +88,26 @@ public class ModelDynBucket implements IModel, IModelCustomData, IRetexturableMo
         ImmutableMap<TransformType, TRSRTransformation> transformMap = IPerspectiveAwareModel.MapWrapper.getTransforms(state);
 
         // if the fluid is a gas wi manipulate the initial state to be rotated 180° to turn it upside down
-        if (flipGas && fluid.isGaseous())
+        if (flipGas && fluid != null && fluid.isGaseous())
         {
             state = new ModelStateComposition(state, TRSRTransformation.blockCenterToCorner(new TRSRTransformation(null, new Quat4f(0, 0, 1, 0), null, null)));
         }
 
         TRSRTransformation transform = state.apply(Optional.<IModelPart>absent()).or(TRSRTransformation.identity());
-        TextureAtlasSprite fluidSprite = bakedTextureGetter.apply(fluid.getStill());
+        TextureAtlasSprite fluidSprite = null;
         ImmutableList.Builder<BakedQuad> builder = ImmutableList.builder();
 
+        if(fluid != null) {
+            fluidSprite = bakedTextureGetter.apply(fluid.getStill());
+        }
+
         if (baseLocation != null)
         {
             // build base (insidest)
             IFlexibleBakedModel model = (new ItemLayerModel(ImmutableList.of(baseLocation))).bake(state, format, bakedTextureGetter);
             builder.addAll(model.getGeneralQuads());
         }
-        if (liquidLocation != null)
+        if (liquidLocation != null && fluidSprite != null)
         {
             TextureAtlasSprite liquid = bakedTextureGetter.apply(liquidLocation);
             // build liquid layer (inside)
@@ -239,7 +243,10 @@ public class ModelDynBucket implements IModel, IModelCustomData, IRetexturableMo
 
             // not a fluid item apparently
             if (fluidStack == null)
+            {
+                // empty bucket
                 return this;
+            }
 
 
             Fluid fluid = fluidStack.getFluid();