This isn't a case of "Robustness principle". Not crashing on invalid input is just plain old decent programming, not to mention secure programming. Programs should not crash on invalid inputs, period. "Robustness" as in the robustness principle refers to trying to actually process invalid data and go make a guess at what the functionality should be.

In fact, you can make quite a case that "robustness" as defined that way is responsible for the horrible mess that HTML and cross-browser compatibility is these days. For instance, if you improperly close tags, or overlap tags, IE (and others I assume) will dutifully go about trying to figure out what you meant: being very "robust" in their interpretation of input outside the spec.

By implementing behaviour outside the spec (being "robust"), you are implicitly extending the spec, and every other browser has to implement unspecified behaviour in the same way.

Reminds me of one of my first jobs. I needed to convert some data into a odd file format based on 100 or so pages of documentation and upload it to an FTP. Problem was the first version I wrote caused their system to crash...

Fun times.

At uni in a software testing subject I was given an assignment to read various input files (some valid, some invalid). If your program crashes, you would get 0 marks. It made for a stressful assignment execution day, but it was a good lesson.

I agree, it's unbelievable. End users don't care about incorrect markup, they care about their browser hanging.

Obviously this is a bug in IE that needs to be fixed and it's Microsoft's responsibility to ensure that their browser doesn't crash in invalid input, but end users don't actually care about the browser either (they don't even know what a browser is), they care about your site crashing.

That's incorrect.

If your TV crashed would you blame the TV program you were watching at the time?

People know the difference between software and content. Content should never be able to crash software.

I agree with you in that content should never be able to crash software.

I disagree with you TV example, however. If the same TV show repeatedly crashed one of the most popular TV models, consumers would blame the show.

well, that would be stupid

Not necessarily - I don't understand how software interacts with, for example, digital cable. I've seen certain channels crash my cable box before. It wouldn't be that surprising to see a certain show reliably crash the cable box.

A topic very much like this one makes up a chapter in the wonderful book Godel, Escher, Bach http://en.wikipedia.org/wiki/G%C3%B6del,_Escher,_Bach

Two characters are in a race: one to build an impervious record player, the other to design a record that - when played - sets up feedback in the record player sufficient to destroy it.

It's a stunningly simple intro to a fairly deep topic: NP completeness, input validation, etc.

"If your TV crashed would you blame the TV program you were watching at the time?"

I'm not positive, but I believe that it's possible for TV shows to crash TVs, which is why there are standards in that specify what kind of content you are allowed to broadcast:

http://en.wikipedia.org/wiki/Broadcast-safe

I had an episode of a TV show on videotape that literally crashed my TV. I'm not kidding. Whenever the show got to a certain point the TV would turn off.

I'm 99% sure that it was something invalid in the closed captioning.

if my TV shut down every time i tried to watch one specific show and never any other time, i might blame that show, yes.

people should know the difference, but they don't.

Back in 2000, I finally switched from Netscape to Internet Explorer because DoubleClick's JS hung Netscape. When a decent number of sites work in one browser but not the other, I go look for another browser.

100% correct in my experience.

I'd say that most do care about their browser. Chrome wouldn't have sped to such popularity otherwise, nor Firefox before it, nor Mozilla, nor... IE. If users didn't care we'd perhaps all still be using Mosaic.

One could make a good argument that Chrome was only adopted due to Google's popularity in the search space, and leveraging that to push messages along the lines of "Upgrade your browser".

Not that there's anything wrong with that, but I don't think Chrome would be anything near what it is today without all of the google.com referrals.

This is most likely true for Chrome yes, but it's almost definitely true for IE. I feel confident claiming that at the very least half of the IE users use it because they don't have a choice or because they got it as default on Windows.

I agree. There is no combination of text that should cause a browser to crash. Why the people in the discussion were blaming the HTML markup is beyond me.

Agree. It's a horrible read. Good thing their marketing department hasn't caught up with this... yet

It probably did. Long time ago. IE on RC build of Windows 8 does not crash.

Well yeah, but 3 years after the fact.

It does not crash the IE build that came with the RC of windows 8. So probably all the comments and the page should use a past tense?