On the revision front, I've now switched to Text Searching and Processing. I've been reading through the textbook, but it's slow going, as there's a lot of "reading between the lines", i.e. when the book says "Clearly it follows that ...", it takes me 10 minutes of staring at it to think "Ah, yes, with you". What's more of a problem is that there have been a few cases where I look at something and think "That can't be right". Which either means:
a) The book is right, and I'm just being dense.
b) The book is wrong, and I know better than my professor, who recently hosted a symposium on stringology, and is a world-renowned expert in this field.
So, I'm cautious about leaping to conclusion b) without spending a lot of time trying to understand the text at face value. But there have been a few cases where I'm sure that I've found a mistake. I emailed the professor about one of them last night, and he confirmed it; he also said that there isn't an errata page (I'd already looked, but couldn't find one), which is a shame. So, I've emailed him another list today.
Once my exams are over, I think I'll add an "errata" section to my website, so that I can list all the errors I've found in textbooks etc., for cases when the publisher doesn't provide this service.