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What is the Best Bug-as-a-Feature?
Bat Country wonders: "The workflow system, at the department I develop for, was hand-coded by my predecessor in a rather short amount of time, resulting in somewhat unreadable code with a number of interesting 'features.' When I took over maintenance of the code base, I started patching bugs and cleaning up the code in preparation for a new set of features. After I was done, I got a pile of complaints about features that had disappeared, which turned out to be caused by the bugs in the code. So, that leads me to ask: what is your favorite bug that you either can't live without or makes your life easier?"
Windows Genuine Advantage
My favorite:
"404 File Not Found
The requested URL (askslashdot/07/03/30/0116246.shtml) was not found."
That little error saved me from having to read a bunch of replies.
it pops up all sorts of porn pages I never even asked for!
Monstar L
rm * .old
The guy who wrote the Windows version actually allows you to turn it on! Overpay the money lender and your money grows at 10% a month! The bug was in the original Apple 2 version and then subsequent ports, like the one to Palm, removed it.
buffer overflows are great - they allow you to get root on all sorts of devices that some bastard tried to lock you out of.
The famous undocmented 320x240 VGA video mode, pre-VESA, and other tweaked VGA modes.
I've heard the 6502 (or, more specifically, RP2A03) had some useful undocumented opcodes. I think they weren't intentional, so they might count.
On the software side...how about exploitable buffer overflows on the Xbox and PSP to enable execution of arbitrary code?
Not a software bug but a design flaw in a car I used to own.
The Vauxhall Astra Mk.2 (Opel Kadett E) had a design flaw in the steering column. Specifically, the steering column was rather weaker than the steering lock.
The upshot of it was when some little scrote decided to try and steal my car (this was way before cars were fitted with immobilisers), when he tried to break the steering lock the steering column snapped and the steering wheel came straight off in his hand.
It was supposed to be a unix clone, but actually came out useful in the end.
I don't need no instructions to know how to rock!!!!
"Subscribe to view" webpages that are still visible to users browsing as GoogleBot.
User agent switcher extension + Browse pretending to be GoogleBot = Annoying "register/pay to see me!" pages go away. I have no idea how many sites it works on now, but I think it still gets into a lot of archived newspaper articles and suchlike.
"We have to go forth and crush every world view that doesn't believe in tolerance and free speech." - David Brin
For me, the physics bug that enabled "skiing" in Starsiege: Tribes was the best bug as a feature. It's a bug that became a key defining point of the series.
A description of skiing is here.
Sendmail
This sig used to be really funny...
Perl is perhaps one large bug that works so well that it's a great feature. For example in perl when you compare two things you get an answer that is stable no matter what the items are. In python you can't and even when you can the answer is not stable. The order of a sorted list can depend on it's orginal ordering! You cant compare floats to Complex numbers but you can compare strings to complex numbers. Sets are grouped by equality not identity so 4.0 and 4 are the same thing for a set. Which one stays and which one get added to the set depends on the ordering of the lists that were put in the set.
it's nuts. And the origin of the nutty ness is an obsessive desire not to have default behaviours. Whereas perl is all default behaviours. In the end perl does what you really meant, and python does what you told it.
in case you think I'm python bashing google what python evangelist david mertz says about python warts.
Some drink at the fountain of knowledge. Others just gargle.
This barely qualifies as bug, more on an inconsistency, but...
In Firefox, when you make a new bookmark, you need to give it a name. FF grays-out the OK button until you do. This implies that bookmarks weren't meant to be nameless. Here's the "bug": if you go to rename the bookmark, you can make it blank and the OK button remains active.
So what good is a nameless bookmark? I place all of my frequently-visited bookmarks on the menu bar, to the right of the menus (it's normally wasted space). I have over 25 bookmarks marks there, and if they had names (even one-letter names), they wouldn't fit by a long-shot. The favicons are all I need, so this ability is pretty helpful, and isn't likely to be fixed.
"When the atomic bomb goes off there's devastation...but when the atomic bong goes off there's celebraaaaation!"
In Second Life, if you zoom your camera up to a wall, you will normally just zoom in to see closer detail of the wall. But once up against the wall, swing the camera around to the side, and you can "back your way in" through the wall. Release and click again, and the camera is now "mounted" inside the house. Its so much fun to watch people inside their homes, especially when your avatar is prevented from entering the property. Some even pay for a little orb that still tells them that no one is detected within 30m. Its fun because the clicks still work, too, like right clicking on someone and IM'ing them.. to tell them that you liked their last outfit more than this one, or the couch looked better in the other corner.. really freaks them out. That is definitely a "bug" (or feature) I couldn't live without... not in SL at least.
Intelligent Life on Earth
There were two oversights in the older VW's electrical system:
... ooops, that's more hardware than software. sorry.
(1) You needed the key to close the sunroof.
(2) But.. a sneak path in the headlight wiring meant you could instead just turn on the headlights and pull on the high-beam flasher (on the turn-signal lever). Enough electricity would flow backwards through the sneak path to operate the sunroof motor.
A related "bug" is the ability to boot Linux "fail safe" with the notation 'initrd=/bin/sh' on the boot line. As MVS would say, "Thou art God!"
-JDF
I'd have to go with strafe jumping in Quake2. What better way to get the 100 health pack in q2dm1 w/out having to sacrifice precious life w/a rocket jump. w00t!
In high school I wrote a program for a physics project that showed electromagnetic wave propagation and interference. Nothing that special, the end result was basically a pretty screensaver with some relevence to physics. In light of that, one of the features I added was a pull-down menu for selecting what color you wanted to use. This was back in the VGA days with a 256 color pallette and manually poking the VGA frame buffer. Due to an off-by-one error in calculating the bounding box of the pull down menu, it was possible to select an invalid index for the color, so instead of selecting a row of the pallette with my nice color gradients set up, it was one of basically random colors. The result was really trippy, so when I discovered the bug, I decided to leave it in. At the open house where my program was running through a projector some bystander discovered the bug and thought it was indeed cool and trippy.
:)
That's about it. Most of my bugs just break shit.
The enemies of Democracy are
A couple of friends of mine in high school CS wrote a Tetris clone for class, but they had a bug where occasionally, blocks would spontaneously appear or disappear. They couldn't figure out how to fix it, so they claimed (in the docs, not to the teacher) that they had AI adjusting the difficulty to match the players' skills.
Media that can be recorded and distributed can be recorded and distributed.
-kfg
Not me, but one of my colleagues took over maintenance of a system which included a date library. The dates and times were treated as floating-point, leading to much conversion and adjustinging. Eg. 12:30 was 12.30, so when adding 40 minutes getting 12.70, and then adjusting that to 13.10, No input validation was done. My colleague tried cleaning that up, but then got complaints from the users. They had discovered the "features" and were now using eg:
January -6th
meaning december 24th the previous year.
My colleague had to remove the input validation again and keep the features.
I think you're describing the Unix feature that you can replace an executable file while it is in use; the program that is using it will continue to see the deleted version of the file, and new programs will see the new version.
That's not a bug, it's a feature. It's the reason why you don't have to reboot Unix machines after a software update, as you do for Windows.
The Rockwell 6502 was a hard-wired processor; there was no "illegal instruction" check. So, any bit-patter you loaded as an instruction would try to do something. Sometimes, because of the internal open-collector busses, you'd get neat "something OR something" that wouldn't normally happen.
Here's the I'm Feeling Lucky hit on it: 6502 Opcodes.
Thing is, the results might vary from implementation to implementation. So they might not work usefully on the 6510, which was otherwise a 6502 with an I/O register at $0000-$0001.
This was a fun one. I had one of the first MINI Coopers, and ordered it with the CD player ('Wave' option? Seem to remember that name). I forget exactly when I took possession of the car, but I think it was around September or October. Something like that.
Anyway, at roughly 2:00am every morning the car alarm would go off, much to the 'delight' of myself, my neighbours and everyone in the vicinity. I'd go out, stop the alarm and then try to sleep. After which it would go off again, every hour or so.As if we weren't losing enough sleep with our then new-born daughter.
The cause was eventually traced, and it's one of the more obscure bugs I've ever come across. Turns out that the car had a low-power rather than completely off mode, and the CD player retained a tiny amount of power going through it. When it was cold, say at 2:00am on an autumn morning for example, the CD player would detect that condensation was forming and would wake up the car's electrics to create some warmth to clear the condensation. This is deliberate, and quite clever I think.
However, the problem came in that it did this too often and started causing a big drop in battery reserves. The security system interpreted this as an attempt to start the car by hotwiring it, and so the alarm would be set off. I'd come out to switch it off, then go back to bed on the cold autumn night at which point condensation would form again, the CD player would switch itself on again, the security system would sound the alarm again and a bleary-eyed version of me would stagger out to turn the alarm off again. At which point condensation would start to form again and...
Bah.
Cheers,
Ian
Guess he didn't get the memo...
though Windows does this with flying (Blue) colors, I would nominate DRM. it screwed music and spurred development of P2P
- Minutus cantorum, minutus balorum, minutus carborata descendum pantorum.
My college dorm elevator had bug/feature. If you briefly pulled and then reset the "emergency stop" button as the elevator was stopping at a floor it would skip that floor. I lived on the third floor and we routinely skipped folks on the second floor waiting for the elevator. This was a great time saving feature (except, of course, when the fourth floor residents would skip the third floor).
The only misfeature of this bug was that the bell would briefly ring alerting those waiting that they had been skipped. One time, some second floor residents heard us skip their floor and we heard them running down after us. We skipped the lobby and went back to the fourth floor. We could have kept it going all night if they tried chasing us, but they didn't. Anyone too lazy to walk to the lobby from the second floor sure isn't going to race up to the fourth floor.
Eventually, they upgraded the elevator and we had to stop for the second floor whenever they wanted.
-- Don't Tase me, bro!
As a programmer, and a former student in at least one other math-related discipline, it's clear to me that 4 and 4.0 are equal. But they are not equivalent. Knowing 'Accuracy', 'Precision' and 'Proper Use Of Units' like the back of your hand will help you in any career.
[Ego]out
As a software developer, I am amused by you all. "4" is quite obviously a string, and can not be compared with 4.0 without a set of business rules.
:)
Multiplying it in silly ways will not help you either.
Lies about crimes
I always enjoyed cars with "child-safe rear windows" which don't roll all the way down. In many cases, this is because the rear wheel well cuts into the door, reducing the space available for the window.