From 96c1691c8546f27430f8278f785a63a46b0b7cfc Mon Sep 17 00:00:00 2001
From: Waiting Idly <25394029+WaitingIdly@users.noreply.github.com>
Date: Sun, 15 Feb 2026 04:56:38 -0800
Subject: [PATCH 1/3] fix matcher check

---
 .../compat/vanilla/ItemStackMixinExpansion.java        | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/main/java/com/cleanroommc/groovyscript/compat/vanilla/ItemStackMixinExpansion.java b/src/main/java/com/cleanroommc/groovyscript/compat/vanilla/ItemStackMixinExpansion.java
index ce7e5326a..d8434624e 100644
--- a/src/main/java/com/cleanroommc/groovyscript/compat/vanilla/ItemStackMixinExpansion.java
+++ b/src/main/java/com/cleanroommc/groovyscript/compat/vanilla/ItemStackMixinExpansion.java
@@ -66,12 +66,16 @@ default ItemStackMixinExpansion exactCopy() {
 
     @Override
     default boolean test(ItemStack stack) {
-        if (!OreDictionary.itemMatches(grs$getItemStack(), stack, false) || (grs$getMatcher() != null && !grs$getMatcher().test(stack))) {
+        var matcher = grs$getMatcher();
+        if (matcher != null) {
+            if (!matcher.test(stack)) return false;
+        } else if (!OreDictionary.itemMatches(grs$getItemStack(), stack, false)) {
             return false;
         }
-        if (grs$getNbtMatcher() != null) {
+        var nbtMatcher = grs$getNbtMatcher();
+        if (nbtMatcher != null) {
             NBTTagCompound nbt = stack.getTagCompound();
-            return nbt != null && grs$getNbtMatcher().test(nbt);
+            return nbt != null && nbtMatcher.test(nbt);
         }
         return true;
     }

From 7178de84bf5ab87aebbf74e7634d396a19e0a04c Mon Sep 17 00:00:00 2001
From: Waiting Idly <25394029+WaitingIdly@users.noreply.github.com>
Date: Sun, 15 Feb 2026 05:02:51 -0800
Subject: [PATCH 2/3] make nbt matchers check item + meta

---
 .../groovyscript/compat/vanilla/ItemStackMixinExpansion.java  | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/main/java/com/cleanroommc/groovyscript/compat/vanilla/ItemStackMixinExpansion.java b/src/main/java/com/cleanroommc/groovyscript/compat/vanilla/ItemStackMixinExpansion.java
index d8434624e..85e9c7fb6 100644
--- a/src/main/java/com/cleanroommc/groovyscript/compat/vanilla/ItemStackMixinExpansion.java
+++ b/src/main/java/com/cleanroommc/groovyscript/compat/vanilla/ItemStackMixinExpansion.java
@@ -202,7 +202,7 @@ default INbtIngredient whenNoNbt() {
         setNbt(null);
         grs$setMatcher(self -> {
             NBTTagCompound nbt = self.getTagCompound();
-            return nbt == null || nbt.isEmpty();
+            return OreDictionary.itemMatches(grs$getItemStack(), self, false) && (nbt == null || nbt.isEmpty());
         });
         return this;
     }
@@ -211,7 +211,7 @@ default INbtIngredient whenAnyNbt() {
         setNbt(new NBTTagCompound());
         grs$setMatcher(self -> {
             NBTTagCompound nbt = self.getTagCompound();
-            return nbt != null && !nbt.isEmpty();
+            return OreDictionary.itemMatches(grs$getItemStack(), self, false) && nbt != null && !nbt.isEmpty();
         });
         return this;
     }

From 5b86827b3b3f504d3980493be2cb02ee4299f680 Mon Sep 17 00:00:00 2001
From: Waiting Idly <25394029+WaitingIdly@users.noreply.github.com>
Date: Sun, 15 Feb 2026 05:09:04 -0800
Subject: [PATCH 3/3] make copies for other when/with methods

---
 .../vanilla/ItemStackMixinExpansion.java      | 29 ++++++++++---------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/src/main/java/com/cleanroommc/groovyscript/compat/vanilla/ItemStackMixinExpansion.java b/src/main/java/com/cleanroommc/groovyscript/compat/vanilla/ItemStackMixinExpansion.java
index 85e9c7fb6..924a6c604 100644
--- a/src/main/java/com/cleanroommc/groovyscript/compat/vanilla/ItemStackMixinExpansion.java
+++ b/src/main/java/com/cleanroommc/groovyscript/compat/vanilla/ItemStackMixinExpansion.java
@@ -194,26 +194,27 @@ default INbtIngredient withNbtExact(NBTTagCompound nbt) {
     }
 
     default INbtIngredient withNbtFilter(Predicate<NBTTagCompound> nbtFilter) {
-        this.grs$setNbtMatcher(nbtFilter == null ? nbt -> true : nbtFilter);
-        return this;
+        ItemStackMixinExpansion itemStackMixin = exactCopy();
+        itemStackMixin.grs$setNbtMatcher(nbtFilter == null ? nbt -> true : nbtFilter);
+        return itemStackMixin;
     }
 
     default INbtIngredient whenNoNbt() {
-        setNbt(null);
-        grs$setMatcher(self -> {
-            NBTTagCompound nbt = self.getTagCompound();
-            return OreDictionary.itemMatches(grs$getItemStack(), self, false) && (nbt == null || nbt.isEmpty());
-        });
-        return this;
+        var itemStackMixin = of(when(stack -> {
+            NBTTagCompound nbt = stack.getTagCompound();
+            return OreDictionary.itemMatches(grs$getItemStack(), stack, false) && (nbt == null || nbt.isEmpty());
+        }));
+        itemStackMixin.setNbt(null);
+        return itemStackMixin;
     }
 
     default INbtIngredient whenAnyNbt() {
-        setNbt(new NBTTagCompound());
-        grs$setMatcher(self -> {
-            NBTTagCompound nbt = self.getTagCompound();
-            return OreDictionary.itemMatches(grs$getItemStack(), self, false) && nbt != null && !nbt.isEmpty();
-        });
-        return this;
+        var itemStackMixin = of(when(stack -> {
+            NBTTagCompound nbt = stack.getTagCompound();
+            return OreDictionary.itemMatches(grs$getItemStack(), stack, false) && nbt != null && !nbt.isEmpty();
+        }));
+        itemStackMixin.setNbt(new NBTTagCompound());
+        return itemStackMixin;
     }
 
     default ItemStack withMeta(int meta) {