SPIGOT-4471: Use wall time for zombie drowning & enhance checks

Thanks Zach Brown for outline of issue with drowned zombies.

nms-patches/EntityZombie.patch

@@ -4,17 +4,40 @@
  import java.util.UUID;
  import javax.annotation.Nullable;
  
-+//CraftBukkit start
++// CraftBukkit start
 +import org.bukkit.event.entity.CreatureSpawnEvent;
 +import org.bukkit.event.entity.EntityCombustByEntityEvent;
 +import org.bukkit.event.entity.EntityCombustEvent;
 +import org.bukkit.event.entity.EntityTargetEvent;
-+//CraftBukkit end
++// CraftBukkit end
 +
  public class EntityZombie extends EntityMonster {
  
      protected static final IAttribute c = (new AttributeRanged((IAttribute) null, "zombie.spawnReinforcements", 0.0D, 0.0D, 1.0D)).a("Spawn Reinforcements Chance");
-@@ -182,7 +189,14 @@
+@@ -21,6 +28,7 @@
+     private int bJ;
+     private float bK;
+     private float bL;
++    private int lastTick = MinecraftServer.currentTick; // CraftBukkit - add field
+ 
+     public EntityZombie(EntityTypes<?> entitytypes, World world) {
+         super(entitytypes, world);
+@@ -143,8 +151,12 @@
+ 
+     public void tick() {
+         if (!this.world.isClientSide) {
+-            if (this.dG()) {
+-                --this.bJ;
++            // CraftBukkit start - Use wall time instead of ticks for conversion
++            if (this.dG() && this.isAlive()) {
++                int elapsedTicks = MinecraftServer.currentTick - this.lastTick;
++                this.lastTick = MinecraftServer.currentTick;
++                this.bJ -= elapsedTicks;
++                // CraftBukkit end
+                 if (this.bJ < 0) {
+                     this.dE();
+                 }
+@@ -182,7 +194,14 @@
              }
  
              if (flag) {
@@ -30,7 +53,7 @@
              }
          }
  
-@@ -221,7 +235,7 @@
+@@ -221,7 +240,7 @@
                  entityzombie.setCustomNameVisible(this.getCustomNameVisible());
              }
  
@@ -39,7 +62,7 @@
              this.die();
          }
      }
-@@ -252,8 +266,8 @@
+@@ -252,8 +271,8 @@
                      if (this.world.getType(new BlockPosition(i1, j1 - 1, k1)).q() && this.world.getLightLevel(new BlockPosition(i1, j1, k1)) < 10) {
                          entityzombie.setPosition((double) i1, (double) j1, (double) k1);
                          if (!this.world.isPlayerNearby((double) i1, (double) j1, (double) k1, 7.0D) && this.world.a_(entityzombie, entityzombie.getBoundingBox()) && this.world.getCubes(entityzombie, entityzombie.getBoundingBox()) && !this.world.containsLiquid(entityzombie.getBoundingBox())) {
@@ -50,7 +73,7 @@
                              entityzombie.prepare(this.world.getDamageScaler(new BlockPosition(entityzombie)), (GroupDataEntity) null, (NBTTagCompound) null);
                              this.getAttributeInstance(EntityZombie.c).b(new AttributeModifier("Zombie reinforcement caller charge", -0.05000000074505806D, 0));
                              entityzombie.getAttributeInstance(EntityZombie.c).b(new AttributeModifier("Zombie reinforcement callee charge", -0.05000000074505806D, 0));
-@@ -276,7 +290,14 @@
+@@ -276,7 +295,14 @@
              float f = this.world.getDamageScaler(new BlockPosition(this)).b();
  
              if (this.getItemInMainHand().isEmpty() && this.isBurning() && this.random.nextFloat() < f * 0.3F) {
@@ -66,7 +89,7 @@
              }
          }
  
-@@ -372,7 +393,7 @@
+@@ -372,7 +398,7 @@
                  entityzombievillager.setCustomNameVisible(entityvillager.getCustomNameVisible());
              }
  
@@ -75,7 +98,7 @@
              this.world.a((EntityHuman) null, 1026, new BlockPosition(this), 0);
          }
  
-@@ -422,7 +443,7 @@
+@@ -422,7 +448,7 @@
                      entitychicken1.setPositionRotation(this.locX, this.locY, this.locZ, this.yaw, 0.0F);
                      entitychicken1.prepare(difficultydamagescaler, (GroupDataEntity) null, (NBTTagCompound) null);
                      entitychicken1.s(true);
@@ -84,7 +107,7 @@
                      this.startRiding(entitychicken1);
                  }
              }
-@@ -495,7 +516,7 @@
+@@ -495,7 +521,7 @@
      }
  
      public void die(DamageSource damagesource) {
@@ -93,7 +116,7 @@
          if (damagesource.getEntity() instanceof EntityCreeper) {
              EntityCreeper entitycreeper = (EntityCreeper) damagesource.getEntity();
  
-@@ -508,6 +529,7 @@
+@@ -508,6 +534,7 @@
                  }
              }
          }

nms-patches/EntityZombieVillager.patch

@@ -8,9 +8,12 @@
  
      public EntityZombieVillager(World world) {
          super(EntityTypes.ZOMBIE_VILLAGER, world);
-@@ -56,6 +57,11 @@
+@@ -54,8 +55,13 @@
+     }
+ 
      public void tick() {
-         if (!this.world.isClientSide && this.isConverting()) {
+-        if (!this.world.isClientSide && this.isConverting()) {
++        if (!this.world.isClientSide && this.isConverting() && this.isAlive()) { // CraftBukkit
              int i = this.dK();
 +            // CraftBukkit start - Use wall time instead of ticks for villager conversion
 +            int elapsedTicks = MinecraftServer.currentTick - this.lastTick;