The Daily WTF: Curious Perversions in Information Technology

The Rounding Error

by Remy Porter in Representative Line on 2025-03-24

At one point, someone noticed that some financial transactions weren't summing up correctly in the C# application Nancy supported. It didn't require Superman or a Peter Gibbons to figure out why: someone was using floating points for handling dollar amounts.

That kicked off a big refactoring project to replace the usage of double types with decimal types. Everything seemed to go well, at least until there was a network hiccup and the application couldn't connect to the database. Let's see if you can figure out what happened:

15 comments - Last comment @ 20:11

Over Extended Methods

by Remy Porter in Feature Articles on 2025-03-20

Jenny had been perfectly happy working on a series of projects for her company, before someone said, "Hey, we need you to build a desktop GUI for an existing API."

The request wasn't the problem, per se. The API, on the other hand, absolutely was.

17 comments - Last comment @ 2025-03-20

Reliability Test

by Remy Porter in CodeSOD on 2025-03-19

Once upon a time, Ryan's company didn't use a modern logging framework to alert admins when services failed. No, they used everyone's favorite communications format, circa 2005: email. Can't reach the database? Send an email. Unhandled exception? Send an email. Handled exception? Better send an email, just in case. Sometimes they go to admins, sometimes they just go to an inbox used for logging.

Let's look at how that worked.

19 comments - Last comment @ 2025-03-23

Spaced Out Prefix

by Remy Porter in CodeSOD on 2025-03-18

Alex had the misfortune to work on the kind of application which has forms with gigantic piles of fields, stuffed haphazardly into objects. A single form could easily have fifty or sixty fields for the user to interact with.

That leads to C# code like this:

15 comments - Last comment @ 2025-03-19

Don't Date Me

by Remy Porter in CodeSOD on 2025-03-13

I remember in some intro-level compsci class learning that credit card numbers were checksummed, and writing basic functions to validate those checksums as an exercize. I was young and was still using my "starter" credit card with a whopping limit of $500, so that was all news to me.

Alex's company had a problem processing credit cards: they rejected a lot of credit cards as being invalid. The checksum code seemed to be working fine, so what could the problem be? Well, the problem became more obvious when someone's card worked one day, and stopped working the very next day, and they just so happened to be the first and last day of the month.

14 comments - Last comment @ 2025-03-19

Expressing a Leak

by Remy Porter in CodeSOD on 2025-03-12

We previously discussed some whitespacing choices in a C++ codebase. Tim promised that there were more WTFs lurking in there, and has delivered one.

Let's start with this class constructor:

20 comments - Last comment @ 2025-03-13

Broken Up With

by Remy Porter in Representative Line on 2025-03-11

Marco found this wreck, left behind by a former co-worker:

$("#image_sample").html('<i><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br />No image selected, select an image to see how it looks in the banner!</i>');

28 comments - Last comment @ 10:29

Where is the Validation At?

by Remy Porter in CodeSOD on 2025-03-10

As oft stated, the "right" way to validate emails is to do a bare minimum sanity check on format, and then send a verification message to the email address the user supplied; it's the only way to ensure that what they gave you isn't just syntactically valid, but is actually usable.

But even that simple approach leaves places to go wrong. Take a look at this code, from Lana.

15 comments - Last comment @ 2025-03-11