Added PotionBrewEvent.Pre/Post. To allow for modification and cancelation of Brewing.

patches/minecraft/net/minecraft/tileentity/TileEntityBrewingStand.java.patch

@@ -9,7 +9,14 @@
                      {
                          int j = this.field_145945_j[i].func_77960_j();
                          int k = this.func_145936_c(j, itemstack);
-@@ -157,7 +157,7 @@
+@@ -151,13 +151,14 @@
+ 
+     private void func_145940_l()
+     {
++        if (net.minecraftforge.event.ForgeEventFactory.onPotionAttemptBreaw(field_145945_j)) return;
+         if (this.func_145934_k())
+         {
+             ItemStack itemstack = this.field_145945_j[3];
  
              for (int i = 0; i < 3; ++i)
              {
@@ -18,7 +25,7 @@
                  {
                      int j = this.field_145945_j[i].func_77960_j();
                      int k = this.func_145936_c(j, itemstack);
-@@ -178,9 +178,9 @@
+@@ -178,9 +179,9 @@
                  }
              }
  
@@ -30,15 +37,15 @@
              }
              else
              {
-@@ -191,6 +191,7 @@
+@@ -191,6 +192,7 @@
                      this.field_145945_j[3] = null;
                  }
              }
-+            net.minecraftforge.common.MinecraftForge.EVENT_BUS.post(new net.minecraftforge.event.brewing.PotionBrewedEvent(field_145945_j));
++            net.minecraftforge.event.ForgeEventFactory.onPotionBrewed(field_145945_j);
          }
      }
  
-@@ -306,7 +307,7 @@
+@@ -306,7 +308,7 @@
  
      public boolean func_94041_b(int p_94041_1_, ItemStack p_94041_2_)
      {

src/main/java/net/minecraftforge/event/ForgeEventFactory.java

@@ -36,6 +36,7 @@ import net.minecraftforge.common.ForgeHooks;
 import net.minecraftforge.common.IExtendedEntityProperties;
 import net.minecraftforge.common.MinecraftForge;
 import net.minecraftforge.common.util.BlockSnapshot;
+import net.minecraftforge.event.brewing.PotionBrewEvent;
 import net.minecraftforge.event.entity.EntityEvent;
 import net.minecraftforge.event.entity.EntityStruckByLightningEvent;
 import net.minecraftforge.event.entity.PlaySoundAtEntityEvent;
@@ -385,4 +386,30 @@ public class ForgeEventFactory
         LivingHealEvent event = new LivingHealEvent(entity, amount);
         return (MinecraftForge.EVENT_BUS.post(event) ? 0 : event.amount);
     }
+
+    public static boolean onPotionAttemptBreaw(ItemStack[] stacks)
+    {
+        ItemStack[] tmp = new ItemStack[stacks.length];
+        for (int x = 0; x < tmp.length; x++)
+            tmp[x] = stacks[x].copy();
+
+        PotionBrewEvent.Pre event = new PotionBrewEvent.Pre(tmp);
+        if (MinecraftForge.EVENT_BUS.post(event))
+        {
+            boolean changed = false;
+            for (int x = 0; x < stacks.length; x++)
+            {
+                changed |= ItemStack.areItemStacksEqual(tmp[x], stacks[x]);
+                stacks[x] = event.getItem(x);
+            }
+            onPotionBrewed(stacks);
+            return true;
+        }
+        return false;
+    }
+
+    public static void onPotionBrewed(ItemStack[] brewingItemStacks)
+    {
+        MinecraftForge.EVENT_BUS.post(new PotionBrewEvent.Post(brewingItemStacks));
+    }
 }

src/main/java/net/minecraftforge/event/brewing/PotionBrewEvent.java

@@ -0,0 +1,83 @@
+package net.minecraftforge.event.brewing;
+
+import net.minecraft.item.ItemStack;
+import net.minecraftforge.fml.common.eventhandler.Cancelable;
+import net.minecraftforge.fml.common.eventhandler.Event;
+import net.minecraftforge.fml.common.eventhandler.Event.HasResult;
+
+
+public class PotionBrewEvent extends Event
+{
+    private ItemStack[] stacks;
+
+    protected PotionBrewEvent(ItemStack[] stacks)
+    {
+        this.stacks = stacks;
+    }
+
+    public ItemStack getItem(int index)
+    {
+        if (index >= stacks.length) return null;
+        return stacks[index];
+    }
+
+    public void setItem(int index, ItemStack stack)
+    {
+        if (index < stacks.length)
+        {
+            stacks[index] = stack;
+        }
+    }
+
+    public int getLength()
+    {
+        return stacks.length;
+    }
+
+    /**
+     * PotionBrewEvent.Pre is fired before vanilla brewing takes place.
+     * All changes made to the event's array will be made to the TileEntity if the event is canceled.
+     * <br>
+     * The event is fired during the TileEntityBrewingStand#brewPotions() method invocation.<br>
+     * <br>
+     * {@link #brewingStacks} contains the itemstack array from the TileEntityBrewer holding all items in Brewer.<br>
+     * <br>
+     * This event is {@link Cancelable}.<br>
+     * If the event is not canceled, the vanilla brewing will take place instead of modded brewing.
+     * <br>
+     * This event does not have a result. {@link HasResult}<br>
+     * <br>
+     * This event is fired on the {@link MinecraftForge#EVENT_BUS}.<br>
+     * <br>
+     * If this event is canceled, and items have been modified, PotionBrewEvent.Post will automatically be fired.
+     **/
+    @Cancelable
+    public static class Pre extends PotionBrewEvent
+    {
+        public Pre(ItemStack[] stacks)
+        {
+            super(stacks);
+        }
+    }
+
+    /**
+     * PotionBrewEvent.Post is fired when a potion is brewed in the brewing stand.
+     * <br>
+     * The event is fired during the TileEntityBrewingStand#brewPotions() method invocation.<br>
+     * <br>
+     * {@link #brewingStacks} contains the itemstack array from the TileEntityBrewer holding all items in Brewer.<br>
+     * <br>
+     * This event is not {@link Cancelable}.<br>
+     * <br>
+     * This event does not have a result. {@link HasResult}<br>
+     * <br>
+     * This event is fired on the {@link MinecraftForge#EVENT_BUS}.<br>
+     **/
+    public static class Post extends PotionBrewedEvent
+    {
+        public Post(ItemStack[] stacks)
+        {
+            super(stacks);
+        }
+    }
+}

src/main/java/net/minecraftforge/event/brewing/PotionBrewedEvent.java

@@ -16,14 +16,18 @@ import net.minecraft.item.ItemStack;
  * <br>
  * This event is fired on the {@link MinecraftForge#EVENT_BUS}.<br>
  **/
-public class PotionBrewedEvent extends Event
+@Deprecated
+public class PotionBrewedEvent extends PotionBrewEvent
 {
     /**
      * The brewing stacks in the brewing stand.  Each index has the possibility to be null, so make sure you check.
+     * Changing this array to another one has no effect.
      */
+    @Deprecated
     public ItemStack[] brewingStacks;
     public PotionBrewedEvent(ItemStack[] brewingStacks)
     {
+        super(brewingStacks);
         this.brewingStacks = brewingStacks;
     }
 }