Paper/nms-patches/EntityPotion.patch

--- a/net/minecraft/server/EntityPotion.java
+++ b/net/minecraft/server/EntityPotion.java
@@ -7,6 +7,13 @@
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
+// CraftBukkit start
+import java.util.HashMap;
+
+import org.bukkit.craftbukkit.entity.CraftLivingEntity;
+import org.bukkit.entity.LivingEntity;
+// CraftBukkit end
+
 public class EntityPotion extends EntityProjectile {
 
     private static final DataWatcherObject<Optional<ItemStack>> d = DataWatcher.a(EntityPotion.class, DataWatcherRegistry.f);
@@ -78,10 +85,11 @@
                 this.world.triggerEffect(2002, new BlockPosition(this), PotionRegistry.a(potionregistry));
                 this.die();
             } else {
-                if (!list.isEmpty()) {
+                if (true || !list.isEmpty()) { // CraftBukkit - Call event even if no effects to apply
                     if (this.isLingering()) {
                         EntityAreaEffectCloud entityareaeffectcloud = new EntityAreaEffectCloud(this.world, this.locX, this.locY, this.locZ);
 
+                        entityareaeffectcloud.projectileSource = this.projectileSource; // CraftBukkit
                         entityareaeffectcloud.setSource(this.getShooter());
                         entityareaeffectcloud.setRadius(3.0F);
                         entityareaeffectcloud.setRadiusOnUse(-0.5F);
@@ -96,11 +104,21 @@
                             entityareaeffectcloud.a(new MobEffect(mobeffect.getMobEffect(), mobeffect.getDuration(), mobeffect.getAmplifier()));
                         }
 
-                        this.world.addEntity(entityareaeffectcloud);
+                        // CraftBukkit start
+                        org.bukkit.event.entity.LingeringPotionSplashEvent event = org.bukkit.craftbukkit.event.CraftEventFactory.callLingeringPotionSplashEvent(this, entityareaeffectcloud);
+                        if (!(event.isCancelled() || entityareaeffectcloud.dead)) {
+                            this.world.addEntity(entityareaeffectcloud);
+                        } else {
+                            entityareaeffectcloud.dead = true;
+                        }
+                        // CraftBukkit end
                     } else {
                         AxisAlignedBB axisalignedbb = this.getBoundingBox().grow(4.0D, 2.0D, 4.0D);
                         List list1 = this.world.a(EntityLiving.class, axisalignedbb);
 
+                        // CraftBukkit
+                        HashMap<LivingEntity, Double> affected = new HashMap<LivingEntity, Double>();
+
                         if (!list1.isEmpty()) {
                             Iterator iterator1 = list1.iterator();
 
@@ -117,21 +135,45 @@
                                             d1 = 1.0D;
                                         }
 
-                                        Iterator iterator2 = list.iterator();
+                                        // CraftBukkit start
+                                        affected.put((LivingEntity) entityliving.getBukkitEntity(), d1);
+                                    }
+                                }
+                            }
+                        }
 
-                                        while (iterator2.hasNext()) {
-                                            MobEffect mobeffect1 = (MobEffect) iterator2.next();
-                                            MobEffectList mobeffectlist = mobeffect1.getMobEffect();
-
-                                            if (mobeffectlist.isInstant()) {
-                                                mobeffectlist.applyInstantEffect(this, this.getShooter(), entityliving, mobeffect1.getAmplifier(), d1);
-                                            } else {
-                                                int i = (int) (d1 * (double) mobeffect1.getDuration() + 0.5D);
-
-                                                if (i > 20) {
-                                                    entityliving.addEffect(new MobEffect(mobeffectlist, i, mobeffect1.getAmplifier()));
-                                                }
-                                            }
+                        org.bukkit.event.entity.PotionSplashEvent event = org.bukkit.craftbukkit.event.CraftEventFactory.callPotionSplashEvent(this, affected);
+                        if (!event.isCancelled() && list != null && !list.isEmpty()) { // do not process effects if there are no effects to process
+                            for (LivingEntity victim : event.getAffectedEntities()) {
+                                if (!(victim instanceof CraftLivingEntity)) {
+                                    continue;
+                                }
+
+                                EntityLiving entityliving = ((CraftLivingEntity) victim).getHandle();
+                                double d1 = event.getIntensity(victim);
+                                // CraftBukkit end
+
+                                Iterator iterator2 = list.iterator();
+
+                                while (iterator2.hasNext()) {
+                                    MobEffect mobeffect1 = (MobEffect) iterator2.next();
+                                    MobEffectList mobeffectlist = mobeffect1.getMobEffect();
+                                    // CraftBukkit start - Abide by PVP settings - for players only!
+                                    if (!this.world.pvpMode && this.getShooter() instanceof EntityPlayer && entityliving instanceof EntityPlayer && entityliving != this.getShooter()) {
+                                        int i = MobEffectList.getId(mobeffectlist);
+                                        // Block SLOWER_MOVEMENT, SLOWER_DIG, HARM, BLINDNESS, HUNGER, WEAKNESS and POISON potions
+                                        if (i == 2 || i == 4 || i == 7 || i == 15 || i == 17 || i == 18 || i == 19) {
+                                            continue;
+                                        }
+                                    }
+                                    // CraftBukkit end
+                                    if (mobeffectlist.isInstant()) {
+                                        mobeffectlist.applyInstantEffect(this, this.getShooter(), entityliving, mobeffect1.getAmplifier(), d1);
+                                    } else {
+                                        int i = (int) (d1 * (double) mobeffect1.getDuration() + 0.5D);
+
+                                        if (i > 20) {
+                                            entityliving.addEffect(new MobEffect(mobeffectlist, i, mobeffect1.getAmplifier()));
                                         }
                                     }
                                 }
@@ -139,10 +181,10 @@
                         }
                     }
                 }
-
-                this.world.triggerEffect(2002, new BlockPosition(this), PotionRegistry.a(potionregistry));
-                this.die();
             }
+
+            this.world.triggerEffect(2002, new BlockPosition(this), PotionRegistry.a(potionregistry));
+            this.die();
         }
     }
 
@@ -152,6 +194,7 @@
 
     private void a(BlockPosition blockposition) {
         if (this.world.getType(blockposition).getBlock() == Blocks.FIRE) {
+            if (org.bukkit.craftbukkit.event.CraftEventFactory.callEntityChangeBlockEvent(this, blockposition, Blocks.AIR, 0).isCancelled()) return; // CraftBukkit
             this.world.setTypeAndData(blockposition, Blocks.AIR.getBlockData(), 2);
         }