Java 8 Update 51; Windows 10
I saw a post on reddit about someone who was tping around in the end, and they saw this weird bug. Instead of posting this bug, he posted a bug about the ender gateways and forgot about this one. Basically I just tp'd around until I found where the glitched.
What I expected to happen was...:
When I tp'd to about 9975300 x in the end, I would see normal outer islands continuing on forever.
What actually happened was...:
When I tp'd to about 9975300 x in the end, I saw normal islands in the -x direction, but in +x there was a giant void ocean. I then tried to see how long it went, and found that other other edge was at about 10273700 x. After this point, the edges of the islands were squares, and the islands were in giant square continents. Very rarely where there islands that were not square, and most of the time these were inside of large square boxes of void. Many 100k long void oceans can be found other than the first one. This also seemed to occur with -x, but I only confirmed that there was glitched terrain, the borders may be in different places.
Steps to Reproduce:
1. Defeat the ender dragon and go through the ender gateway.
2. Teleport yourself to 9975300 x; y or z did not matter for me.
3. You will see that in -x, the ender islands are normal, but in +x, there is a very large void ocean.
4. Teleport yourself to 10273700 x; y or z did not matter for me.
5. You will see that in -x, there is the large ocean, but in +x are very glitched ender islands (look at the side of the ocean coast.) You can fly along these glitched islands for a long time without finding another void ocean.