Programming

I joined a team and was assigned a bug that had been bugging them for two years. Randomly files they saved would be corrupted.

Eventually isolated it to the third party library they used to serialize the data. For some reason this library corrupted file names that were an odd length. So "cat" would get corrupted while "cats" would save and load just fine. It was a black box library we didn't control so was told to just program a workaround to check filename length and append a character if it was odd and move on.

I still want to know what that library was doing.

I worked at an IoT platform startup. All of our embedded device demos stopped working August 1st. I was told the same thing happened last year, but it was fine, things would start working in September. I decided to go fix it anyway. Eventually I figured out the culprit was a custom HTTP library. Instead of doing anything sensible, the way it found the Content-Length header was to loop over the bytes of the response until it found the first 'g' add 5 to that pointer and then assume that whatever was there was the number of bytes it should read. Unfortunately, HTTP responses have a Date header which includes the month and August has a 'g' in it.

There were a bunch of these demo devices already flashed and shipped out. The 'fix' to get them to work, even in August, was to downgrade requests to HTTP 0.9 which didn't require a Date header in the response.

Early in the GNOME /wayland transition, there was a bug I hit where you could drag windows off the edge of the screen, and somehow the desktop would scroll. It was kinda cool conceptually, but completely broken functionally, as it was hard to scroll back.

Edit: Wayland was actually the solution, Xorg was the problem:

https://programming.dev/pictrs/image/bc70285d-88ac-42aa-80be-b8b8f012547b.png

https://programming.dev/post/6905486

OPAM (OCaml's package manager) had a bug where it couldn't find curl or wget to download stuff with (don't ask me why it shelled out to those in the first place) if you were in more than 32 Unix groups. Have fun thinking of a reasonable explanation for that!

Load 2TB of data into ram during startup. Prompt user credentials to continue. Whoops, we need to do cryptography on those credentials... Free the heap. Invalid creds force exits. Valid creds goes gray until those 2TB are loaded back into memory... From storage halfway across the country over the 3mbps link, the best available in BFE.

I use a 3D CAD software that once you switch to 3D mode, it makes things partially transparent, but it does so by scaling the opacity of the entire window. The end result is that transparent parts look correct when you have a black desktop background, but otherwise you'll see what's on the window behind it or the desktop background. Same issue when you get gaps between two sides or curves. I think no one noticed because they would usually launch it from a terminal, so they always had black backgrounds.

It’s not a bug per se, and we’re gonna see a lot of this moving forward.

Did a code review, hefty code review, and as I got to the end of it where “the magic happened” I discovered that the logic was actually a case statement for every permutation.

Because they’d asked the AI to write logic to go through each type, the AI wrote a case statement for EACH TYPE.

… it was so fucking fast though. So wrong but so so fast compared to the actual running code.

Right clicking the title bar of a window on Linux Mint, the menu appears but I can't click it until I move the window away from it (the menu doesn't close) and then it becomes responsive. I love Linux.

I recently tried Pop!OS liveUSB without a mouse connected to PC, there were some accessibility issues but one was unrelated to mouse and pretty cursed:

I chose system language to be something non-latin-based, and ended up with a keyboard layout that can't input English text. There was no way to change the layout and adding the US layout didn't work, because system showed that the US layout is already the one and only available. So I couldn't input commands to set things up but also couldn't click in the UI to set things up

Once upon a time I worked with a CMS that allowed an admin to delete the CMS itself and also any web server that ran it. Poof: gone. Fun times.

Chrome sometimes scrambles json like this. If I copy the scrambled json, it's fine when I paste it

TIC-80 has terrible performance on firefox browser. But when you open the firefox debug logger to try pinpoint the issue it runs flawlessly.

Win32 MFC desktop application, should be able to run continuously unsupervised for days or weeks. When I log in via RDP it crashed. Yes, just in that moment. In the end I figured it out.

MFC supports multiple visual styles, such as classic Windows, few Office versions and few more. We used feature for loading (possibly translated) strings (resource) from various DLLs. First from a currently active plug-in DLL, if the string was not there, then from a sub-system DLL, if it was not there then from main EXE. Plus there was some logic about translation and fallback to English in case of missing or not up-to-date translation. The cause was in one of the MFC visual styles, it changed a global variable related to that string loading thing for a short duration of time, then changed it back. It was only in one of the styles and there was no need to change it, the code could just load the value and use it as a parameter to a function that needed it. Our code in a different thread failed to load a string and threw an exception. Cross a COM interface boundary. Every COM method is decorated by a bunch of macros our senior engineer didn't understand and was not willing to learn. One of the macros was noexcept. Thus an exception being thrown cross an noexcept boundary crashed our app.

Not a bug I experienced but read about https://www.bleepingcomputer.com/news/microsoft/microsoft-fixes-word-bug-that-deleted-documents-when-saving/

Not sure if it fully fits, but one of my old HTC android phones has a bug where it would randomly fail any network request, by just never finishing it. No timeouts either.

It never got fixed. Loading a page in the browser, got stuck, and would need a new refresh. Some apps like Baconreader would get stuck doing the same, any app could have it happen. But sometimes the stars align, Facebooks Messenger had (has? don't see it anymore) the chat bubbles that showed over whatever else on the screen. And i clicked one of those, and they got stuck loading. And there was literally no way to close it. There was no timeouts, so i eventually had to hold the power button and reboot...

Other notable mentions, Spotify on android did not handle duplicated files (since you could add your own music to it) with the same filename or at least artist - title metadata. It would always only play one of them. It was very interesting because Spotify on pc worked, so i could play the second track fine there, but if i told it to continue play through my phone then it would continue form the same timestamp on other track.... Might be related to my phone being stupid, but there was a whole range of infuriating spotify issues. So i just moved to use poweramp and store and sync local music since i had a lot there to begin with .