Ensure entity is always dying before Death Event

Prior to this it was possible for plugins to put the server into a never
ending recursive loop until it eventually killed itself.

Fixes GH-1432

.gitignore

@@ -34,6 +34,7 @@ work/Spigot-Server
 work/Spigot-API
 work/*.jar
 work/test-server
+work/ForgeFlower
 
 # Mac filesystem dust
 .DS_Store/

Spigot-Server-Patches/0356-Improve-death-events.patch

@@ -1,4 +1,4 @@
-From b8c6e5d80cd3b21db5b3d9a031439d37143eb467 Mon Sep 17 00:00:00 2001
+From 61dddacb42c358d24f53ae3a28e5a49eca53d271 Mon Sep 17 00:00:00 2001
 From: Phoenix616 <mail@moep.tv>
 Date: Tue, 21 Aug 2018 01:39:35 +0100
 Subject: [PATCH] Improve death events
@@ -69,7 +69,7 @@ index dca497072..454c1e7d0 100644
      }
  
 diff --git a/src/main/java/net/minecraft/server/EntityLiving.java b/src/main/java/net/minecraft/server/EntityLiving.java
-index 14637be49..dec4b442c 100644
+index 14637be49..5ccd3ea6f 100644
 --- a/src/main/java/net/minecraft/server/EntityLiving.java
 +++ b/src/main/java/net/minecraft/server/EntityLiving.java
 @@ -75,14 +75,14 @@ public abstract class EntityLiving extends Entity {
@@ -140,7 +140,7 @@ index 14637be49..dec4b442c 100644
  
 -            this.aU = true;
 -            this.getCombatTracker().g();
-+            //this.aU = true;
++            this.aU = true; // Paper - Always set at start, unset later if cancelled - GH-1432
 +            //this.getCombatTracker().g();
 +
 +            org.bukkit.event.entity.EntityDeathEvent deathEvent = null;
@@ -148,7 +148,7 @@ index 14637be49..dec4b442c 100644
              if (!this.world.isClientSide) {
                  int i = 0;
  
-@@ -1136,15 +1145,32 @@ public abstract class EntityLiving extends Entity {
+@@ -1136,15 +1145,33 @@ public abstract class EntityLiving extends Entity {
  
                      this.a(flag, i, damagesource);
                      // CraftBukkit start - Call death event
@@ -178,13 +178,14 @@ index 14637be49..dec4b442c 100644
 +                this.setDying(true);
 +                this.world.broadcastEntityEffect(this, (byte) 3);
 +            } else {
++                this.setDying(false); // Paper - reset if cancelled
 +                this.setHealth((float) deathEvent.getReviveHealth());
 +            }
 +            // Paper end
          }
      }
  
-@@ -1198,6 +1224,7 @@ public abstract class EntityLiving extends Entity {
+@@ -1198,6 +1225,7 @@ public abstract class EntityLiving extends Entity {
          return SoundEffects.bX;
      }
  
@@ -192,7 +193,7 @@ index 14637be49..dec4b442c 100644
      @Nullable
      protected SoundEffect cf() {
          return SoundEffects.bS;
-@@ -1583,10 +1610,12 @@ public abstract class EntityLiving extends Entity {
+@@ -1583,10 +1611,12 @@ public abstract class EntityLiving extends Entity {
  
      }
  
@@ -412,5 +413,5 @@ index cce4acc0b..f1a3ca950 100644
       * Server methods
       */
 -- 
-2.18.0.windows.1
+2.19.0