No longer use an arbitrary offset to locate the correct map

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

@@ -37,17 +37,15 @@ public class WorldMap extends WorldMapBase {
         // CraftBukkit start
         byte dimension = nbttagcompound.c("dimension");
 
-        if (dimension >= 10) {
+        this.worldUID = nbttagcompound.getLong("WorldUID");
-            this.worldUID = nbttagcompound.getLong("WorldUID");
+        CraftWorld world = (CraftWorld) server.getWorld(this.worldUID);
-            CraftWorld world = (CraftWorld) server.getWorld(this.worldUID);
+        // Check if the stored world details are correct.
-            // Check if the stored world details are correct.
+        if (world == null) {
-            if (world == null) {
+            /* All Maps which do not have their valid world loaded are set to a dimension which hopefully won't be reached.
-                /* All Maps which do not have their valid world loaded are set to a dimension which hopefully won't be reached.
+               This is to prevent them being corrupted with the wrong map data. */
-                   This is to prevent them being corrupted with the wrong map data. */
+            dimension = 127;
-                dimension = 127;
+        } else {
-            } else {
+            dimension = (byte) world.getHandle().dimension;
-                dimension = (byte) world.getHandle().dimension;
-            }
         }
 
         this.map = dimension;