From b29947e0d00b8a2b937724dc8bd675969626039c Mon Sep 17 00:00:00 2001
From: Thinkofdeath <thinkofdeath@spigotmc.org>
Date: Thu, 31 Jul 2014 17:48:20 +0100
Subject: [PATCH] Filter attribute modifiers which cause the attribute to go
 out of its range


diff --git a/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaItem.java b/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaItem.java
index ec37524..bcde85c 100644
--- a/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaItem.java
+++ b/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaItem.java
@@ -38,6 +38,8 @@ import com.google.common.collect.ImmutableMap;
 
 // Spigot start
 import static org.spigotmc.ValidateUtils.*;
+import net.minecraft.server.GenericAttributes;
+import net.minecraft.server.IAttribute;
 // Spigot end
 
 /**
@@ -256,6 +258,123 @@ class CraftMetaItem implements ItemMeta, Repairable {
             NBTTagList save = null;
             NBTTagList nbttaglist = tag.getList(ATTRIBUTES.NBT, 10);
 
+            // Spigot start
+            net.minecraft.util.gnu.trove.map.hash.TObjectDoubleHashMap<String> attributeTracker = new net.minecraft.util.gnu.trove.map.hash.TObjectDoubleHashMap<String>();
+            net.minecraft.util.gnu.trove.map.hash.TObjectDoubleHashMap<String> attributeTrackerX = new net.minecraft.util.gnu.trove.map.hash.TObjectDoubleHashMap<String>();
+            Map<String, IAttribute> attributesByName = new HashMap<String, IAttribute>();
+            attributeTracker.put( "generic.maxHealth", 20.0 );
+            attributesByName.put( "generic.maxHealth", GenericAttributes.maxHealth );
+            attributeTracker.put( "generic.followRange", 32.0 );
+            attributesByName.put( "generic.followRange", GenericAttributes.b );
+            attributeTracker.put( "generic.knockbackResistance", 0.0 );
+            attributesByName.put( "generic.knockbackResistance", GenericAttributes.c );
+            attributeTracker.put( "generic.movementSpeed", 0.7 );
+            attributesByName.put( "generic.movementSpeed", GenericAttributes.d );
+            attributeTracker.put( "generic.attackDamage", 1.0 );
+            attributesByName.put( "generic.attackDamage", GenericAttributes.e );
+            NBTTagList oldList = nbttaglist;
+            nbttaglist = new NBTTagList();
+
+            List<NBTTagCompound> op0 = new ArrayList<NBTTagCompound>();
+            List<NBTTagCompound> op1 = new ArrayList<NBTTagCompound>();
+            List<NBTTagCompound> op2 = new ArrayList<NBTTagCompound>();
+
+            for ( int i = 0; i < oldList.size(); ++i )
+            {
+                NBTTagCompound nbttagcompound = oldList.get( i );
+                if ( nbttagcompound == null ) continue;
+
+                if ( !( nbttagcompound.get( ATTRIBUTES_UUID_HIGH.NBT ) instanceof NBTTagLong ) )
+                {
+                    continue;
+                }
+                if ( !( nbttagcompound.get( ATTRIBUTES_UUID_LOW.NBT ) instanceof NBTTagLong ) )
+                {
+                    continue;
+                }
+                if ( !( nbttagcompound.get( ATTRIBUTES_IDENTIFIER.NBT ) instanceof NBTTagString ) || !CraftItemFactory.KNOWN_NBT_ATTRIBUTE_NAMES.contains( nbttagcompound.getString( ATTRIBUTES_IDENTIFIER.NBT ) ) )
+                {
+                    continue;
+                }
+                if ( !( nbttagcompound.get( ATTRIBUTES_NAME.NBT ) instanceof NBTTagString ) || nbttagcompound.getString( ATTRIBUTES_NAME.NBT ).isEmpty() )
+                {
+                    continue;
+                }
+                if ( !( nbttagcompound.get( ATTRIBUTES_VALUE.NBT ) instanceof NBTTagDouble ) )
+                {
+                    continue;
+                }
+                if ( !( nbttagcompound.get( ATTRIBUTES_TYPE.NBT ) instanceof NBTTagInt ) || nbttagcompound.getInt( ATTRIBUTES_TYPE.NBT ) < 0 || nbttagcompound.getInt( ATTRIBUTES_TYPE.NBT ) > 2 )
+                {
+                    continue;
+                }
+
+                switch ( nbttagcompound.getInt( ATTRIBUTES_TYPE.NBT ) )
+                {
+                    case 0:
+                        op0.add( nbttagcompound );
+                        break;
+                    case 1:
+                        op1.add( nbttagcompound );
+                        break;
+                    case 2:
+                        op2.add( nbttagcompound );
+                        break;
+                }
+            }
+            for ( NBTTagCompound nbtTagCompound : op0 )
+            {
+                String name = nbtTagCompound.getString( ATTRIBUTES_IDENTIFIER.NBT );
+                if ( attributeTracker.containsKey( name ) )
+                {
+                    double val = attributeTracker.get( name );
+                    val += nbtTagCompound.getDouble( ATTRIBUTES_VALUE.NBT );
+                    if ( val != attributesByName.get( name ).a( val ) )
+                    {
+                        continue;
+                    }
+                    attributeTracker.put( name, val );
+                }
+                nbttaglist.add( nbtTagCompound );
+            }
+            for ( String name : attributeTracker.keySet() )
+            {
+                attributeTrackerX.put( name, attributeTracker.get( name ) );
+            }
+            for ( NBTTagCompound nbtTagCompound : op1 )
+            {
+                String name = nbtTagCompound.getString( ATTRIBUTES_IDENTIFIER.NBT );
+                if ( attributeTracker.containsKey( name ) )
+                {
+                    double val = attributeTracker.get( name );
+                    double valX = attributeTrackerX.get( name );
+                    val += valX * nbtTagCompound.getDouble( ATTRIBUTES_VALUE.NBT );
+                    if ( val != attributesByName.get( name ).a( val ) )
+                    {
+                        continue;
+                    }
+                    attributeTracker.put( name, val );
+                }
+                nbttaglist.add( nbtTagCompound );
+            }
+            for ( NBTTagCompound nbtTagCompound : op2 )
+            {
+                String name = nbtTagCompound.getString( ATTRIBUTES_IDENTIFIER.NBT );
+                if ( attributeTracker.containsKey( name ) )
+                {
+                    double val = attributeTracker.get( name );
+                    val += val * nbtTagCompound.getDouble( ATTRIBUTES_VALUE.NBT );
+                    if ( val != attributesByName.get( name ).a( val ) )
+                    {
+                        continue;
+                    }
+                    attributeTracker.put( name, val );
+                }
+                nbttaglist.add( nbtTagCompound );
+            }
+
+            // Spigot end
+
             for (int i = 0; i < nbttaglist.size(); ++i) {
                 if (!(nbttaglist.get(i) instanceof NBTTagCompound)) {
                     continue;
-- 
1.9.1