I found out what the problem was, and how to reproduce, but this turned out to be intended. (stairs don't allow redstone connections from below them)
Alright, I got the world back, but how do I fix the corruption?
How does a world get corrupted? Also, is there a way to fix this?
What happened?
Agh! Help! A chunk of my world has regenerated!
I'm not sure how to reproduce, since I tried this on a different world and it worked.
Also, I should have said that the block that was above the bookshelf was wooden planks, and I was trying to connect the redstone from there.
Actually, I can't, because the file is too large to attach.
Sure.
Singleplayer survival.
And no, I was playing on my survival world.
Here's the report.
I just found out this is a false report. Ignore, again...
This issue is false. Please ignore it.
this isn't a bug, since the purple part of the portal is made of individual blocks, not just one huge portal.