1 files changed, 13 insertions, 5 deletions
diff --git a/src/main/java/gtPlusPlus/xmod/gregtech/common/tileentities/machines/multi/production/chemplant/MTEChemicalPlant.java b/src/main/java/gtPlusPlus/xmod/gregtech/common/tileentities/machines/multi/production/chemplant/MTEChemicalPlant.java
index 1e5d1bb9ea..f678f084fc 100644
--- a/src/main/java/gtPlusPlus/xmod/gregtech/common/tileentities/machines/multi/production/chemplant/MTEChemicalPlant.java
+++ b/src/main/java/gtPlusPlus/xmod/gregtech/common/tileentities/machines/multi/production/chemplant/MTEChemicalPlant.java
@@ -545,21 +545,25 @@ public class MTEChemicalPlant extends GTPPMultiBlockBase<MTEChemicalPlant> imple
         }
     }
 
-    private void damageCatalyst(@Nonnull ItemStack aStack, int minParallel) {
+    /**
+     * @return if the catalyst item is fully destroyed as a result of the damage applied.
+     */
+    private boolean damageCatalyst(@Nonnull ItemStack aStack, int minParallel) {
         // Awakened Draconium Coils with Tungstensteel Pipe Casings (or above) no longer consume catalysts.
-        if (!isCatalystDamageable()) return;
+        if (!isCatalystDamageable()) return false;
         for (int i = 0; i < minParallel; i++) {
             if (MathUtils.randFloat(0, 10000000) / 10000000f < (1.2f - (0.2 * this.mPipeCasingTier))) {
                 int damage = getDamage(aStack) + 1;
                 if (damage >= getMaxCatalystDurability()) {
                     addOutput(CI.getEmptyCatalyst(1));
                     aStack.stackSize -= 1;
-                    return;
+                    return aStack.stackSize == 0;
                 } else {
                     setDamage(aStack, damage);
                 }
             }
         }
+        return false;
     }
 
     private boolean isCatalystDamageable() {
@@ -592,6 +596,9 @@ public class MTEChemicalPlant extends GTPPMultiBlockBase<MTEChemicalPlant> imple
                     if (catalyst == null) {
                         return SimpleCheckRecipeResult.ofFailure("no_catalyst");
                     }
+                } else {
+                    // remove reference to the old catalyst if our new recipe doesn't use it
+                    catalyst = null;
                 }
                 return CheckRecipeResultRegistry.SUCCESSFUL;
             }
@@ -608,8 +615,9 @@ public class MTEChemicalPlant extends GTPPMultiBlockBase<MTEChemicalPlant> imple
             @NotNull
             @Override
             protected CheckRecipeResult onRecipeStart(@NotNull GTRecipe recipe) {
-                if (catalyst != null) {
-                    damageCatalyst(catalyst, getCurrentParallels());
+                if (!GTUtility.isStackValid(catalyst) || damageCatalyst(catalyst, getCurrentParallels())) {
+                    // remove reference to the catalyst if it is invalid, or if the damage destroys it
+                    catalyst = null;
                 }
                 return super.onRecipeStart(recipe);
             }