Lost or corrupted undo-tree history

Lost or corrupted undo-tree history 6 January 2020 Undo-tree is the most popular of the Emacs packages I wrote and maintain,not least because it's used by Evil and Spacemacs. However, for many years, the internet has been awashwith reports of undo history being lost or corrupted when using undo-tree-mode. Trouble was, though I do all my text editing in Emacs, and always have global-undo-tree-mode enabled, I'd never encountered these issues myself. And no one had ever been able to send me a recipe for reliably reproducing them. Making it fiendishly difficult to even begin to investigate what might be going on.

This post is about some recent changes to undo-tree that might finally address these issues.

How to include material after the letter in newlfm

How to include material after the letter in newlfm 25 November 2018

TL;DR: If you want to include additional material after the closing of a newlfm letter, forget the builtin \restletter commands. Add \newcommand\closelfm{\closlfm\let\closlfm\relax} to your letrinfo.tex file, put \closelfm where you want to end the letter (optionally followed by a \newpage), then write the additional material using standard LaTeX markup.

I use the newlfm LaTeX package for all letters I write, personal and professional. It has some nice advantages over the standard letter document class: you can have a database of different sender and recipient addresses, signatures and letterheads; it's easy to create custom letterheads that include images; you can have the correct letterhead and signature selected automatically based on sender or recipient. And many other features I don't make use of.

I have a love-hate relationship with this package, though. It has some quirks/bugs, especially to do with page layout and spacing. And whilst the documentation is extensive, it's not always the clearest. Whenever I need to do anything slightly different to what I've done before with newlfm, getting it to do what I want typically involves hours of effort and frustration the first time around, and I often ending up resorting to ugly kludges to get the letter written without wasting too much time. (This probably says more about my limitations, than those of the package.) Nonetheless, once you have a letter layout configured just the way you want, writing new letters with the same layout with newlfm is a breeze.

I was recently writing a cover letter to accompany the revisions I was submitting to one of my research papers. I wanted to attach the detailed response to the referees' comments after the letter (which contained a lot of mathsso was best written in LaTeX too). The easy thing would have been to write the cover letter using newlfm, write the review response as a separate LaTeX document using some other document class, and stitch the two PDFs together using the pdftk command-line tool (or similar). But having to write these as two separate documents bugged me. I was already writing the cover letter in LaTeX. Why not just write the detailed referee response in the same LaTeX document?

Why I use TMDA

Why I use TMDA 16 July 2005 Mine is a sad and familiar story. I was drowning in a deluge of spam (a.k.a. junk email), and it had become such a problem that email was fast becoming useless for me. Having to sort through and delete hundreds of spam emails per day was bad enough. Worse was the increasing frequency with which I was accidentally deleting legitimate email along with the spam.

There are various ways to fight this deluge of spam. The most common is to use a filter that tries to recognise and delete the spam (or, more usually, move it to a spam box for later perusal). This is quite effective. A small amount of spam will not be recognised as such (false-negatives), and will end up in your inbox anyway. But the amount of spam will usually be cut down to a manageable amount, rendering email usable again.

The problem with the filtering approach is the false-positives: legitimate mail that gets mis-identified as spam. Even if it's moved to a spam box rather than deleted, when you're searching through hundreds of spam emails you're almost certain to miss the one or two legitimate mails hiding amongst them, and you'll delete them along with the spam. (At least, that's what I found myself doing.)

A second approach is to use techniques such as domain blocking, real-time blacklists, and other methods of blocking whole groups of addresses known to send spam. But this is really just a variation on filtering (filters usually take the sender's address into account when deciding whether an email is spam or not, as well as the body).

I didn't want to run the risk of someone sending me an email, me deleting it accidentally, and them never knowing that I didn't received it. So I chose to use a third approach: white-list plus challenge/response (plus a number of other features of the impressive TMDA system).

Emailing me

Email address

I can be reached by email at toby@dr-qubit.org, associated with this PGP key:

BB74 FB42 4C64 4CB7 3571  39AA A96F 4A67 4DC3 9B79


