SPIGOT-161: Don't apply velocity changes if we didn't damage on explosion.

nms-patches/Explosion.patch

@@ -1,5 +1,5 @@
---- ../work/decompile-8eb82bde//net/minecraft/server/Explosion.java	2014-11-28 17:43:43.189707433 +0000
-+++ src/main/java/net/minecraft/server/Explosion.java	2014-11-28 17:38:22.000000000 +0000
+--- ../work/decompile-8eb82bde/net/minecraft/server/Explosion.java	2015-01-25 10:44:43.764182684 +1100
++++ src/main/java/net/minecraft/server/Explosion.java	2015-01-25 10:44:43.768182687 +1100
 @@ -8,6 +8,12 @@
  import java.util.List;
  import java.util.Map;
@@ -49,22 +49,26 @@
                                  hashset.add(blockposition);
                              }
  
-@@ -112,7 +125,14 @@
+@@ -112,7 +125,17 @@
                          double d12 = (double) this.world.a(vec3d, entity.getBoundingBox());
                          double d13 = (1.0D - d7) * d12;
  
+-                        entity.damageEntity(DamageSource.explosion(this), (float) ((int) ((d13 * d13 + d13) / 2.0D * 8.0D * (double) f3 + 1.0D)));
 +                        // entity.damageEntity(DamageSource.explosion(this), (float) ((int) ((d13 * d13 + d13) / 2.0D * 8.0D * (double) f3 + 1.0D)));
 +                        
 +                        // CraftBukkit start
 +                        CraftEventFactory.entityDamage = source;
-                         entity.damageEntity(DamageSource.explosion(this), (float) ((int) ((d13 * d13 + d13) / 2.0D * 8.0D * (double) f3 + 1.0D)));
++                        boolean wasDamaged = entity.damageEntity(DamageSource.explosion(this), (float) ((int) ((d13 * d13 + d13) / 2.0D * 8.0D * (double) f3 + 1.0D)));
 +                        CraftEventFactory.entityDamage = null;
++                        if (!wasDamaged) {
++                            continue;
++                        }
 +                        // CraftBukkit end
 +
                          double d14 = EnchantmentProtection.a(entity, d13);
  
                          entity.motX += d8 * d14;
-@@ -140,6 +160,35 @@
+@@ -140,6 +163,35 @@
          BlockPosition blockposition;
  
          if (this.b) {
@@ -100,7 +104,7 @@
              iterator = this.blocks.iterator();
  
              while (iterator.hasNext()) {
-@@ -170,7 +219,8 @@
+@@ -170,7 +222,8 @@
  
                  if (block.getMaterial() != Material.AIR) {
                      if (block.a(this)) {
@@ -110,7 +114,7 @@
                      }
  
                      this.world.setTypeAndData(blockposition, Blocks.AIR.getBlockData(), 3);
-@@ -184,8 +234,12 @@
+@@ -184,8 +237,12 @@
  
              while (iterator.hasNext()) {
                  blockposition = (BlockPosition) iterator.next();