From 4937b44c5d747600ae076b7c5f895bba2553ddf9 Mon Sep 17 00:00:00 2001
From: mezz <tehgeek@gmail.com>
Date: Fri, 20 Oct 2017 23:17:02 -0700
Subject: [PATCH] Fix duplicate items when they are added by a mod at runtime
 from the API

---
 .../java/mezz/jei/ingredients/IngredientRegistry.java | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/main/java/mezz/jei/ingredients/IngredientRegistry.java b/src/main/java/mezz/jei/ingredients/IngredientRegistry.java
index 271012449..5bfae0036 100644
--- a/src/main/java/mezz/jei/ingredients/IngredientRegistry.java
+++ b/src/main/java/mezz/jei/ingredients/IngredientRegistry.java
@@ -165,15 +165,20 @@ public <V> void addIngredientsAtRuntime(Class<V> ingredientClass, List<V> ingred
 		IIngredientHelper<V> ingredientHelper = getIngredientHelper(ingredientClass);
 		//noinspection unchecked
 		Set<V> set = ingredientsMap.computeIfAbsent(ingredientClass, k -> IngredientSet.create(ingredientClass, ingredientHelper));
+		List<V> newIngredients = new ArrayList<>(ingredients.size());
 		for (V ingredient : ingredients) {
-			set.add(ingredient);
+			if (set.add(ingredient)) {
+				newIngredients.add(ingredient);
+			}
 			if (ingredient instanceof ItemStack) {
 				getStackProperties((ItemStack) ingredient);
 			}
 		}
 
-		NonNullList<IIngredientListElement> ingredientListElements = IngredientListElementFactory.createList(this, ingredientClass, ingredients, modIdHelper);
-		ingredientFilter.addIngredients(ingredientListElements);
+		if (!newIngredients.isEmpty()) {
+			NonNullList<IIngredientListElement> ingredientListElements = IngredientListElementFactory.createList(this, ingredientClass, newIngredients, modIdHelper);
+			ingredientFilter.addIngredients(ingredientListElements);
+		}
 	}
 
 	@Override