Fix NPE while trying to respawn an already disconnected player (#11353)

patches/server/Add-PlayerPostRespawnEvent.patch

@@ -24,12 +24,19 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
  
              if (!flag) entityplayer.reset(); // SPIGOT-4785
 +            // Paper start - Add PlayerPostRespawnEvent
++            if (dimensiontransition == null) return entityplayer; // Early exit, mirrors belows early return for disconnected players in respawn event
 +            isRespawn = true;
 +            location = CraftLocation.toBukkit(dimensiontransition.pos(), dimensiontransition.newLevel().getWorld(), dimensiontransition.yRot(), dimensiontransition.xRot());
 +            // Paper end - Add PlayerPostRespawnEvent
          } else {
              dimensiontransition = new DimensionTransition(((CraftWorld) location.getWorld()).getHandle(), CraftLocation.toVec3D(location), Vec3.ZERO, location.getYaw(), location.getPitch(), DimensionTransition.DO_NOTHING);
          }
+         // Spigot Start
+-        if (dimensiontransition == null) {
++        if (dimensiontransition == null) { // Paper - Add PlayerPostRespawnEvent - diff on change - spigot early returns if respawn pos is null, that is how they handle disconnected player in respawn event
+             return entityplayer;
+         }
+         // Spigot End
 @@ -0,0 +0,0 @@ public abstract class PlayerList {
              if (iblockdata.is(Blocks.RESPAWN_ANCHOR)) {
                  entityplayer1.connection.send(new ClientboundSoundPacket(SoundEvents.RESPAWN_ANCHOR_DEPLETE, SoundSource.BLOCKS, (double) blockposition.getX(), (double) blockposition.getY(), (double) blockposition.getZ(), 1.0F, 1.0F, worldserver.getRandom().nextLong()));