While I was studying at university between 2011-2014, I used
OpenBSD as my main work and development environment. My Lenovo X61s
laptop had trouble with suspend while docked on Linux, but OpenBSD worked fine.
So I ran OpenBSD. Occasionally, I would use the
vi editor (aka nvi) for
writing emails and reports — there was something in its crude simplicity.
I remember typing an email one morning at the university’s hallway when
just crashed. I was stunned.
vi isn’t exactly a piece of software that gets
features (bugs) added to it on yearly basis nor is it a program void of users.
vi was crashing in the year 2013.
When you hit a bug, you try to reproduce it. I built
vi with debug symbols
and tried to reproduce the issue. This wasn’t a trivial task. I remember
spending the entire afternoon trying to trace my steps backwards on what I had
done. In the evening I had traced the bug to word-erase (^W). In some cases
hitting ^W would result in off-by-one and crash the editor.
The next day I created the patch and submitted it to the openbsd-tech mailing list. While writing the patch I started wondering how old was this issue. Luckily the history of nvi was available as a Git repo and I was able to trace the issue to a commit from 13th of April 1995!
After a round of review, a second off-by-one was spotted in the same handler. The version 2 of the patch was merged a few days later.