PaperMC/nms-patches/EntityAnimal.patch

--- a/net/minecraft/server/EntityAnimal.java
+++ b/net/minecraft/server/EntityAnimal.java
@@ -8,6 +8,7 @@
 
     public int loveTicks;
     public UUID breedCause;
+    public ItemStack breedItem; // CraftBukkit - Add breedItem variable
 
     protected EntityAnimal(EntityTypes<? extends EntityAnimal> entitytypes, World world) {
         super(entitytypes, world);
@@ -42,6 +43,9 @@
 
     }
 
+    /* CraftBukkit start
+    // Function disabled as it has no special function anymore after
+    // setSitting is disabled.
     @Override
     public boolean damageEntity(DamageSource damagesource, float f) {
         if (this.isInvulnerable(damagesource)) {
@@ -51,6 +55,7 @@
             return super.damageEntity(damagesource, f);
         }
     }
+    // CraftBukkit end */
 
     @Override
     public float a(BlockPosition blockposition, IWorldReader iworldreader) {
@@ -139,6 +144,7 @@
         if (entityhuman != null) {
             this.breedCause = entityhuman.getUniqueID();
         }
+        this.breedItem = entityhuman.inventory.getItemInHand(); // CraftBukkit
 
         this.world.broadcastEntityEffect(this, (byte) 18);
     }