What is the Best Bug-as-a-Feature? 861
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?"
The money lender bug in Taipan (Score:5, Interesting)
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.
Not sure if this is a bug... but (Score:4, Interesting)
This allows us to deploy our java Jar's to our Folders on our network where the users launch the app from.
Yay.
IE6 is packed with 'features' (Score:4, Interesting)
I'll leave the provision of an exhausitive list to somebody else, but suffice to say if you're looking for a sizeable seam of bugs-which-simultaneously-screw-you-over-and-help
"Subscribe to view" pages visible to Googlebot. (Score:5, Interesting)
User agent switcher extension [chrispederick.com] + 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.
Skiing in Starsiege: Tribes (Score:5, Interesting)
A description of skiing is here [wikipedia.org].
Perl versus Python (Score:5, Interesting)
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.
Nameless Firefox Bookmarks (Score:5, Interesting)
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.
Street Fighter 2 (Score:2, Interesting)
VW close the sunroof bug (Score:5, Interesting)
(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.
telnet -l "-froot" (Score:5, Interesting)
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!"
Quake2 strafe jumping (Score:5, Interesting)
I dunno (Score:5, Interesting)
That's about it. Most of my bugs just break shit.
Re:"Subscribe to view" pages visible to Googlebot. (Score:5, Interesting)
Of course, both are examples of why you shouldn't use "User-Agent" to try and detect what browser or bot is using your webpage. The first allows "illegitimate" users access, and the second blocks legitimate users.
In fact, you shouldn't trust headers for anything unless you have a secure session. To control access to your webpage to robots, use ROBOTS.TXT or a meta tag, and to control access to other users, password protect. But the trouble is that sites are trying to eat their cake (be crawled and indexed) and have it too (control access to ordinary users).
Re:The money lender bug in Taipan (Score:3, Interesting)
In general, I actually liked Tactics' bugs.
Memory segment B000? (Score:1, Interesting)
Physics bugs in video games are the best (Score:5, Interesting)
When the developers saw the potential it gave the game, they left it in. They realized how it made the game unique and exciting, and this bug became the standard feature that sets Tribes far apart from almost all FPS games out there, even to this day. This bug resulted in probably the closest simulation to virtual athleticism that I have ever seen, which was responsible for the fanatical, but small fanbase the Tribes series had.
rich text indent vs. blockquote in IE (Score:3, Interesting)
there's a set of commands that you can execute on the iframe after you've set this property. one of them is "indent". when handled properly, this should create a new div element with some kind of margin or padding on the left. well in IE executing that command actually creates a blockquote element.
completely wrong, right? yes, but convenient. in our CMS we need to be able to create a blockquote, and have no use for indentation, and i cant find any other way to do it in IE. fortunately, in better browsers blockquote is handled with the command "formatblock: blockquote".
SQLDeveloper (Score:2, Interesting)
Date library (Score:5, Interesting)
January -6th
meaning december 24th the previous year.
My colleague had to remove the input validation again and keep the features.
Re:I dunno (Score:4, Interesting)
The Easy to Interpret Save Files in X-COM (Score:5, Interesting)
By ordering a bunch of equipment and saving your game just before it was due to arrive (call that save game A) then saving again immediately after it arrives (call that save game B), and then copying this file from save game A to save game B, you could get whatever equipment you had ordered to arrive again. And again, and again. And you could turn around and sell all the extra stuff for cash.
Lather, Rinse, Repeat. I used to start off a game by repeating this trick until I had maxed out my cash. I found the corresponding file that allowed you to improve your tech without actually performing the research, but that was less of an advantage, since the game used your tech-level to decide how difficult the scenarios it gave you should be.
BMW MINI CD player as burglar alarm trigger (Score:5, Interesting)
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
Template Metaprogramming? (Score:5, Interesting)
Bug in ILO MP3 player (Score:3, Interesting)
There are two bugs here that I know of, one which is a problem all the time, and one that can be used to solve that problem.
The one that is a problem is that if you are listening to a track when you power it off, then remove that track, it will lock up the next time you power up, because it can't find the track you were listening to before.
The other one is that if the key-lock switch is on when you push power to turn it on, it will start to boot up, and get most of the way there before checking the state of the key-lock switch.
However, you can use the second bug as a workaround for the first, because, when it discovers that the key lock switch is set, it will turn around and save its state to the flash. The only thing is, it hadn't loaded its state from the flash yet, so it ends up saving back a clean state.
Re:QW strafejumping (Score:4, Interesting)
For example, in Quake 3, the sampling of the position of the player in 3 dimensions is tied to the frame rate. When the player jumps, in the physics model, the player appears in successive, discrete position along a pre-computed parabolic trajectory. Only at key frame rates, a position sample appears at the peak of the parabola. Players running at these key frame rates are thus able to jump higher. Some custom maps feature areas that are accessible only to players knowing this trick.
There is also a Quake 3 mod (Defrag) which was created to facilitate finding map bugs (e.g. rebounds, which happen when you can fall with absolutely no x or y speed component on some surfaces, happens when the z velocity gets reversed). This leads to impressive "trick jumps" which do not violate the rules of the game (since they are done without modifying the game engine). A quick look in Google and you can find many trick-jumping videos based both on synchronisation and on physics model bugs.
Re:One of my favorites, from console gaming... (Score:3, Interesting)
It was coded in assembly language and the monsters were kept in a pair of parallel tables. Whenever you swung at a monster, it did a loop similar to:
LDX #$1F
CHECK1: LDA MONX,X
CMP HITX
BNE NEXT1
LDA MONY,X
CMP HITY
BEQ HIT
NEXT1: DEX
BNE CHECK1
MISS:
As noted in the comment, the (B)ranch (N)ot (E)qual should be a (B)ranch if (MI)nus. The upshot being that you could never hit the 0th monster on a map. Rather than find/fix the bug, they just mentioned that you will occasionally encounter monsters who are simply invincible.
Re:I dunno (Score:5, Interesting)
Years later I started learning about chaos theory and fractals, and something in my head clicked. I instantly had a vivid memory of that bugged screen and realized that it was a fractal. I had accidentally created a rather complex fractal. Blew my mind clean up.
Re:GPOW (Score:4, Interesting)
How about that great bug in many 8-bit ninendo games where you could "scroll" and enemy off the screen instead of killing it. I think SMB had this bug, bug-turned-feature, but many other games had it as well.
Re:QW strafejumping (Score:4, Interesting)
Open Office Find&Replace to reformat Cells (Score:4, Interesting)
If you do a regex search and replace in Open office and replace all contents of cells with themselves (search for .*, replace with &, or something like that) the contents of the cells will be reformated to whatever default you set for the columns. You can use it to change a column of numbers into a text field (to sort alphanumerically) or vice versa,, (if you have a spreadsheet that imported numbers as text and and you want to change them back into numbers)
This trick is even included in the help documentation.
Outlook Favorites.... (Score:3, Interesting)
P.S. BTW - before you all start complaining about Outlook, if you do configure Outlook properly it is just as secure as anything else. In all the years I've used Outlook (since December 1997), I have only had 2 virii run in it - and I did those myself purposely. The trick - turn off any kind of Autopreview functionality (e.g. Reading Pane, Preview, Autopreview, etc.), and set Outlook to use the Restricted Internet Zone - those two will prevent most things from being functional or running automatically.
Re:VW close the sunroof bug (Score:1, Interesting)
After driving, I begin closing everything to park the car. Usually the sunroof first, and then the windows while the sunroof is sliding shut. But fairly often when i do this, the sunroof will stop or reverse (going all the way back open).
Speaking of Metroid... (Score:2, Interesting)
Mockball: If you start running, then do a spinning jump/somersault, and morph into ball form just as you're landing, you can roll around at running speeds. The main benefit of this little maneuver is to get super missiles early, allowing you to skip the Spore Spawn miniboss.
Damage avoidance: If you shoot an enemy just as it is about to hit you it won't damage you...until the flashing animation stops, at any rate.
Murderbeam: Normally the game doesn't allow you to equip all beams at once (IIRC Plasma and Spazer conflict with each other). However, if you time some button presses in the status menu correctly you can glitch the game into enabling all the beams. Normally, the game will freeze immediately when you try firing this beam, but there are at least two or three places you can use it to your advantage.
1) If used at the right time during the battle with Motherbrain, you can make the battle go much more quickly (and create some interesting graphical glitches, too!).
2a) If you open a door and then fire the murderbeam into the door and then manage to jump through the door before the game crashes on you, chances are you'll find yourself in a completely different room than you intended. More importantly, all game events seem to be reset including items. Using this trick, you can collect over 100% of the items in game.
2b) I haven't seen/done this myself, but I hear if you use the murderbeam reset glitch in the right spot, you can flat out skip Ridley and Motherbrain by somehow triggering the final escape sequence early. Apparently this one only works on emulators, but I need to research it more. For the record, 2a tends to be more successful on the console although I hear there is one location that works in ZSNES.
Anyone who enjoyed Super Metroid back in the day should check out some of the Metroid fansites. There are several more tricks and glitches that allow you to complete the game in just about any order you like. It all comes together to pretty much seal the game's position as my all-time favorite. But no one cares what I think.
My favorite bug (Score:5, Interesting)
How do you do it? Well, here is one reasonable way.
Sort the items in the list.
Duplicate items will be adjacent, so scan through the list and add items when they aren't equal to the last item.
Since it was lisp, I naturally started writing a recursive quicksort.
My code looked something like.
quicksort (list)
if list has size less than 2, return list
Pick pivot from list
L = filter items in list < pivot
G = filter items in list > pivot
return quicksort(L) + pivot + quicksort(R)
However, my quicksort had a bug in it.
Look closely.
It didn't append copies of pivot to the returned sorted list. Thus, it removed them. Since every item eventually ends up as the pivot, all duplicates are removed. It's the only bug that has ever ended up saving me time.
Easy data-entry (Score:2, Interesting)
VW turn the fans on while the car isn't on bug (Score:3, Interesting)
With the key in or out of the ignition (don't turn it to ACC or ON) hit the AC button and turn your fans to full. Then pull your highbeams. Your fans will suddenly turn on. Found it on a forum years ago...was pretty funny the first time I tried it.
minus world (Score:1, Interesting)
Re:Perl versus Python (Score:5, Interesting)
The rule in his example is:
4(1 sig fig) * 1200 (2 sig figs) = 5000 (1 sig fig & rounded up since 4800 is closer to 5000 than 4000)
4.0(2 sig figs) * 1200 (2 sig figs) = 4800 (2 sig figs)
As far as software using sig figs, well...if you are using real world measurements, you should be using sig figs. You can not tell from a general ruler if you are at 0.526876". You can tell that you are between 0.5" and 0.6", so you say 0.56" Past two sig figs, you would really be pulling that out of your bum. Therefore in all the calulations that use the 0.56", you can only have a max of two sig figs in the result. Anything more would rely on you knowing up to say 3+ sig figs in all the numbers used to get the result.
Point: The number of sig figs you have makes a difference in your result. Sig figs are generally used with real world measurement systems. Computer calculations may not fall into this category, but it would depend.
Re:GPOW (Score:2, Interesting)
Did you ever identify item #9 in Wizardry with your Bishop? Or item "number" M?
I don't know if that qualifies as a bug or an easter egg, but it sure made Wizardry very interesting for the next 5 minutes, after which it became suddenly very boring forever. (I guess that qualifies as a rotten easter egg.)
Re:Not sure if youd call it a bug but... (Score:5, Interesting)
This is faster than logging off and back on, leaves the users programs open, but gives you the full admin desktop, not just a shell or explorer window.
It's too bad gksudo doesn't work on Windows...
Re:VW close the sunroof bug (Score:1, Interesting)
The 'crack' in DAOC (Score:2, Interesting)
The DAOC system would recognise when someone left the propoer geometry, would think it an error situation, and had a recovery mode which would return people to their last bind site. In other words, it was a nice quick exit from the mines (without having to die).
It was a bug exploit that everyone seemed to think was perfectly OK, perhaps because no one was a loser and everyone gained.
Re:QW strafejumping (Score:4, Interesting)
A player could be launched all the way across an outdoor map by a teammate with a fully loaded rocket launcher shot to the legs or ground immediately next to the player. Combined with some sloping surfaces, such launches could be easily performed while being very accurate. On AS-Mason such rocket launch could get a player all the way over all defenses and just an elevator ride to the final goal. That is, unless the other team is aware of the launch and has people waiting there.
It's also possible to launch players with the impact hammer, but from experience it's a little harder to perform with people who aren't familiar with the technique. While looking for some illustrations, I noticed that the wikipedia has a few paragraphs [wikipedia.org] about launching, so I won't go into more details here.
What the wikipedia article doesn't seem to mention is that it's also possible to launch your translocator pretty far with the impact hammer, for example from the top of one of the towers on CTF-Face to one of the balconies on the opposite one. Another one, which I never actually mastered, was book launch/jump. It involves standing on a book object, like those lying around on the floor in libraries, and then either hitting it with the hammer, or having someone else shoot it (I think). This, of course, also resulted in a huge jump, and is probably more of a bug than the other methods.
Most of these methods seem to be just exaggerations of standard physics, since both the impact hammer and rocket launcher are supposed to throw stuff around. At first, I found these tricks frustrating, but IMO they add a lot to the game. Especially Assault, which otherwise becomes a spam-fest with everyone camping the choke points like it's some kind of counterstrike. Epic probably recognized this, so they never changed this in UT99, but all of this is sadly gone in UT03/04.
Re:rm (Score:4, Interesting)
Re:Not sure if this is a bug... but (Score:3, Interesting)
Re:I dunno (Score:3, Interesting)
Re:404 (Score:3, Interesting)
Keyboard not found.
Press to continue.
That's actually a BIOS error, but the funny thing is that it isn't entirely useless. For years I had a malfunctioning keyboard that would generate a no keyboard found error on boot-up but when you pressed a key, the computer would finish its boot-up and would work just fine.
Triple Faulting the 80286 processor (Score:5, Interesting)
Re:Perl versus Python (Score:3, Interesting)
Don't like it? The best thing about standards is that there are so many to choose from.
I've worked at a place where someone way-back-when decided that the widely-used IEEE floating point standards weren't good enough, and rolled his own. Mostly like the usual floating point, but with the number of bits assigned to exponent and mantissa "tweaked" to his liking. Unfortunately, one of the most useful things you can do in an embedded data logger is to share your data with the rest of the world -- requiring a conversion to a more "standard" standard.
I don't know what your beef with IEEE floating point is, but there's something to say for a standard form of expression. I'm guessing that you would want some info stored regarding the precision and accuracy of the value recorded. That would be nice. It would also be nice if everyone using floating point values understood those concepts in the first place. And if I had a million dollars.
Re:buffer overflow (Score:3, Interesting)
Reminds me of a buffer overflow in a cheap consumer router http://en.wikipedia.org/wiki/WRT54G [wikipedia.org]
You could then use this bug to get rid of the crappy pre-installed firmware and load your own copy of linux (which gave you an industry-grade router for under $40).
This same bug was later used to force Lynksys to comply with GNU GPL.
Re:Perl versus Python (Score:3, Interesting)
Re:Perl versus Python (Score:4, Interesting)
If you need more 4.00000 parts, you could use tighter machining tolerances, but each part will be much more expensive. The choice of which method depends on a variety of factors, not the least of which is whether you can use the "rejects" as "low quality parts" or "scrap."
Re:Perl versus Python (Score:2, Interesting)
Re:walking corpse in Science and Industry (Score:3, Interesting)
VT100 superfast-repeat, combined with keyclick (Score:4, Interesting)
On a real VT100 (no emulators, please) send an ESC [137q
In other words, even though your keyboard only has 4 LEDs, pretend you wanted to turn on the 137th one. Don't ask, just do it.
Now your keyboard will repeat at an insane rate. Go into Setup B, and turn on keyclick (which might be kind of hard given how crazy your keyboard is acting; maybe you should do that before you send the weirdo escape sequence).
Now hold down a key. Listen. Hold down a different key. Listen. Hey, it sounds a little different.
Now play music.
Re:Did you clean up the code or break the code? (Score:1, Interesting)
It is especially dangerous when the wet-behind-the-ears guy is not a programmer but an admin holding root access to many essential machines. My college's servers were working perfectly until this new admin came about and start to break things in the most interesting and unexplainable ways. I've seen mail servers went down during working hours just because he decided it's time to upgrade it. And, predictably, he broke it. For a week. To make it even better, somehow he got around to delete all mails that were collecting during that week (presumably because he saw that some directory suddenly grow in size) and didn't have any backups. Why in the hell he upgrade the mail server without learning how it works in the first place is beyond me.
After that ordeal, one by one the system went wrong. DNS, file server, etc you name it. Home directories containing backups would mysteriously disappear (and not coming back). Passwords got reset. Internal network became dog slow. Things got so weird that most of us in our lab decided not to trust the system anymore and have our own backup and DNS servers. Me and some of my colleagues removed ourselves from the Windows domain in the off chance that he might break our workstations accidentally.
I dunno about that (Score:3, Interesting)
While I take your point, I just drove back from a chicken plant today and I dealt there with a number of people much older and more experienced than me and making a hell of a lot more money, and I seriously doubt that any of them would have had their careers enhanced by knowing more about those things you mention. In the few instances where those things become important they just hire people like me to sort it all out, and even that doesn't happen very often. (Of course these same people have a "seat of the pants" knowledge of their industry that would blow away most engineers trying to learn what they do from scratch, but they can't quantify or justify a lot of their knowledge in the sense that a scientist or engineer can.)
Re:The best (Score:5, Interesting)
This has made it very convenient when running Windows under an emulator and yet be able to talk over TCP/IP to the host OS. VMWare and other advanced emulators solve this problem by setting up extra local networks and patching directly into the networking stack, but with Windows that's not strictly necessary, as you can bounce packets of a gateway that the emulated OS really shouldn't be able to reach.
Re:The best (Score:3, Interesting)
In this particular instance, the features were related to ad-reps exploiting holes in the original deadlines and scheduling code and as a result short-changing the company and giving clients hundreds of dollars in free advertising (without realizing it) because circumventing the deadlines helped them meet quota.
When the complaints started rolling in, I immediately brought the matter to the attention of my superiors (the ad managers) and the discovery that people had been relying on certain border effects (not directly related to the exploits, but related to other scheduling malfunctions) resulted in a change of policies.
This made both the ad-reps and the management happy, and at the end of the day, that's not a bad position to be in.
C compiler detects infinite loops automatically! (Score:2, Interesting)
Re:The best (Score:3, Interesting)
As these people were our only clients for that subsystem I changed the tab order back to what it was with big comments as to why it was done this way. Ive often wondered if it ever got changed back... or were there other users of this software somewhere in the world wondering wat kinda crack the programmer was on when s/he chose the tab ordering...