java.lang.NullPointerException
at dan200.turtle.shared.TurtleTool.dig(TurtleTool.java:125)

Our server has people mining with turtles. They usually have world anchor coverage of their mining area, but in the case of the crashes the turtles may have traveled outside of the coverage area. The last incident (log below) seemed to happen when there was a turtle mining out of range of a world anchor on a mystcraft world, and the last player left that world via linking book.

The line of code that it errors on appears to have a null value for "position" (Minecraft.jar amw class world entity position), the position of the turtle. It's trying to get the world coordinates of the block to be dug from the turtle's world position and some static orientation vectors from the Minecraft.jar "j" class.

Crash log:
SpoilerTime: 2/2/13 4:47 PM
Description: Exception in server tick loop
java.lang.NullPointerException
at dan200.turtle.shared.TurtleTool.dig(TurtleTool.java:125)
at dan200.turtle.shared.TurtleTool.useTool(TurtleTool.java:107)
at dan200.turtle.shared.TileEntityTurtle.useTool(TileEntityTurtle.java:1508)
at dan200.turtle.shared.TileEntityTurtle.dig(TileEntityTurtle.java:1496)
at dan200.turtle.shared.TileEntityTurtle.updateCommands(TileEntityTurtle.java:2484)
at dan200.turtle.shared.TileEntityTurtle.g(TileEntityTurtle.java:2324)
at xe.h(World.java:2020)
at ie.h(WorldServer.java:463)
at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:649)
at hg.r(DedicatedServer.java:241)
at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:585)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:492)
at fp.run(SourceFile:818)
Relevant Details:
- Minecraft Version: 1.4.2
- Operating System: Windows Server 2008 R2 (amd64) version 6.1
- Java Version: 1.7.0_07, Oracle Corporation
- Java VM Version: Java HotSpotâ„¢ 64-Bit Server VM (mixed mode), Oracle Corporation
- Memory: 708490288 bytes (675 MB) / 2114256896 bytes (2016 MB) up to 2114256896 bytes (2016 MB)
- JVM Flags: 2 total; -Xmx2048M -Xms2048M
- AABB Pool Size: 10566 (591696 bytes; 0 MB) allocated, 1420 (79520 bytes; 0 MB) used
- FML: ~ERROR~ NullPointerException: null
- Is Modded: Definitely; 'forge,fml'
- Profiler Position: N/A (disabled)
- Vec3 Pool Size: 1953 (109368 bytes; 0 MB) allocated, 1953 (109368 bytes; 0 MB) used