Don't create tile entity when block placement fails. Fixes BUKKIT-2924

End portals can only be placed in the end during the dragon's death.
Attempts to place them outside of this window causes the block to remove
itself. However, we still create the tile entity for the portal which
leads to exceptions spamming the console about a tile entity existing
without the appropriate block. In these cases we should not place the tile
entity at all.

src/main/java/net/minecraft/server/Chunk.java

@@ -437,6 +437,12 @@ public class Chunk {
                     }
 
                     if (Block.byId[l] instanceof BlockContainer) {
+                        // CraftBukkit start - don't create tile entity if placement failed
+                        if (this.getTypeId(i, j, k) != l) {
+                            return false;
+                        }
+                        // CraftBukkit end
+
                         tileentity = this.e(i, j, k);
                         if (tileentity == null) {
                             tileentity = ((BlockContainer) Block.byId[l]).a(this.world);