added support for negative items in <= 1.10

src/main/java/de/florianmichael/viafabricplus/injection/mixin/fixes/minecraft/MixinItemRenderer.java

@@ -17,7 +17,11 @@
  */
 package de.florianmichael.viafabricplus.injection.mixin.fixes.minecraft;
 
+import com.viaversion.viaversion.api.protocol.version.ProtocolVersion;
+import de.florianmichael.viafabricplus.protocolhack.ProtocolHack;
 import de.florianmichael.viafabricplus.settings.groups.VisualSettings;
+import net.minecraft.client.font.TextRenderer;
+import net.minecraft.client.render.VertexConsumerProvider;
 import net.minecraft.client.render.item.ItemModels;
 import net.minecraft.client.render.item.ItemRenderer;
 import net.minecraft.client.render.model.BakedModel;
@@ -25,11 +29,13 @@ import net.minecraft.entity.LivingEntity;
 import net.minecraft.item.ItemStack;
 import net.minecraft.item.Items;
 import net.minecraft.world.World;
+import org.joml.Matrix4f;
 import org.spongepowered.asm.mixin.Final;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.Shadow;
 import org.spongepowered.asm.mixin.injection.At;
 import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.Redirect;
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
 
 @Mixin(ItemRenderer.class)
@@ -43,4 +49,11 @@ public class MixinItemRenderer {
             cir.setReturnValue(this.models.getModelManager().getMissingModel());
         }
     }
+
+    @Redirect(method = "renderGuiItemOverlay(Lnet/minecraft/client/util/math/MatrixStack;Lnet/minecraft/client/font/TextRenderer;Lnet/minecraft/item/ItemStack;IILjava/lang/String;)V",
+            at = @At(value = "INVOKE", target = "Lnet/minecraft/client/font/TextRenderer;draw(Ljava/lang/String;FFIZLorg/joml/Matrix4f;Lnet/minecraft/client/render/VertexConsumerProvider;Lnet/minecraft/client/font/TextRenderer$TextLayerType;II)I"))
+    public int recolor(TextRenderer instance, String text, float x, float y, int color, boolean shadow, Matrix4f matrix, VertexConsumerProvider vertexConsumers, TextRenderer.TextLayerType layerType, int backgroundColor, int light) {
+        if (ProtocolHack.getTargetVersion().isOlderThanOrEqualTo(ProtocolVersion.v1_10) && text.startsWith("-")) color = -43213;
+        return instance.draw(text, x, y, color, shadow, matrix, vertexConsumers, layerType, backgroundColor, light);
+    }
 }

src/main/java/de/florianmichael/viafabricplus/injection/mixin/fixes/minecraft/item/MixinItemStack.java

@@ -28,20 +28,43 @@ import net.minecraft.entity.attribute.EntityAttributeModifier;
 import net.minecraft.entity.attribute.EntityAttributes;
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.item.*;
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.Shadow;
-import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.*;
 import org.spongepowered.asm.mixin.injection.*;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
 
 import java.util.OptionalDouble;
 
-@Mixin(ItemStack.class)
+@SuppressWarnings("ConstantValue")
+@Mixin(value = ItemStack.class, priority = 1)
 public abstract class MixinItemStack {
 
     @Shadow
     public abstract Item getItem();
 
+    @Shadow @Final public static ItemStack EMPTY;
+
+    @Shadow private int count;
+
+    @Shadow private boolean empty;
+
+    @Inject(method = "updateEmptyState", at = @At("HEAD"), cancellable = true)
+    public void allowNegativeItems(CallbackInfo ci) {
+        if (ProtocolHack.getTargetVersion().isOlderThanOrEqualTo(ProtocolVersion.v1_10)) {
+            this.empty = false;
+            final ItemStack self = (ItemStack) (Object) this;
+            this.empty = self == EMPTY || this.getItem() == null || self.isOf(Items.AIR) && count != 0;
+            ci.cancel();
+        }
+    }
+
+    @Inject(method = "isEmpty", at = @At("HEAD"), cancellable = true)
+    public void dontRecalculateState(CallbackInfoReturnable<Boolean> cir) {
+        if (ProtocolHack.getTargetVersion().isOlderThanOrEqualTo(ProtocolVersion.v1_10)) {
+            cir.setReturnValue(this.empty);
+        }
+    }
+
     @Inject(method = "getMiningSpeedMultiplier", at = @At("RETURN"), cancellable = true)
     private void modifyMiningSpeedMultiplier(BlockState state, CallbackInfoReturnable<Float> ci) {
         final Item toolItem = ((ItemStack) (Object) this).getItem();

src/main/java/de/florianmichael/viafabricplus/injection/mixin/fixes/viaversion/protocol1_11to1_10/MixinEntityIdRewriter.java

@@ -0,0 +1,32 @@
+/*
+ * This file is part of ViaFabricPlus - https://github.com/FlorianMichael/ViaFabricPlus
+ * Copyright (C) 2021-2023 FlorianMichael/EnZaXD and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package de.florianmichael.viafabricplus.injection.mixin.fixes.viaversion.protocol1_11to1_10;
+
+import com.viaversion.viaversion.api.minecraft.item.Item;
+import com.viaversion.viaversion.protocols.protocol1_11to1_10.EntityIdRewriter;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Redirect;
+
+@Mixin(value = EntityIdRewriter.class, remap = false)
+public class MixinEntityIdRewriter {
+
+    @Redirect(method = "toClientItem(Lcom/viaversion/viaversion/api/minecraft/item/Item;Z)V", at = @At(value = "INVOKE", target = "Lcom/viaversion/viaversion/api/minecraft/item/Item;setAmount(I)V"))
+    private static void allowNegativeItems(Item instance, int i) {
+    }
+}

src/main/resources/viafabricplus.mixins.json

@@ -131,6 +131,7 @@
     "fixes.viaversion.MixinCommonBoss",
     "fixes.viaversion.MixinNBTType",
     "fixes.viaversion.MixinProtocolVersion",
+    "fixes.viaversion.protocol1_11to1_10.MixinEntityIdRewriter",
     "fixes.viaversion.protocol1_11to1_10.MixinProtocol1_11To1_10",
     "fixes.viaversion.protocol1_12to1_11_1.MixinChatItemRewriter",
     "fixes.viaversion.protocol1_13to1_12_2.MixinAbstractFenceConnectionHandler",