User inputs and App crash - hard to dealt with!

Input character sets are not impossible to define theoretically but in real world how many character set would we define to make test data is a question. With two recent issues in the real world makes it a common scenario that testing was done with limited number of sets.  

If an app is set to be used for a specific purpose or by specific group of people, it is little bit easier to define the guessable sets. When an app is open to use to the world, target audience is, to me, infinite (not theoretical infinite). It is pretty much unobtainable to go through different sets - symbols, group of symbol, symbols in specific sequence, combination of different symbols. Here I’m referring the symbols for letters and symbols. 

Little bit backtrack why I started to write this …. Within a week, I came to know two incidents – one with iPhone message app and another is skype app on windows. 

Skype is used for sending messages, which used to be their primary use at earlier time, now days like smart phone, skype has many other features. On the latest version of skype, if anyone sends a message with the characters “http://:” from a windows pc, it crashes skype and receiving a message with those characters make it crash as well. Then the option is to uninstall the skype and reinstall it. It MAY work as long as you did not have the history turned on at the time of sending/receiving message. If the history is on, skype will crash and will not run. There could be some other ways to handle it, but that surely is not desirable by the end user


Picture curtesy: http://venturebeat.com/ If you want you can read more in details from this link. 

Another similar thing happened recently with the iPhone message app. Someone received a text from a group message with some symbols/ letters (non-English) and when they open the message, the messenger app stopped working.  Users who receive a mysterious string of characters in a text are noticing their Messages app will consequently crash, and in some cases, the phone will automatically reboot, according to9to5.

Now, if we look into the Skype message again you will see there is a “:” after the http:// which makes it really unusual to type. User may accidently type it and this (can) happen.  Based on the probability it’s had much lower chances, but it happened. 

For the iPhone message, this is hard to understand any meaning of the symbols, all the Greek to me and it may be greek to the Greek people as well. Chances of such message may be <.00001% or even less. But it happened. 

There will be bugs and it may happen. I understand that as well. But the problem is, things like this is spreading on the internet. Some curious people are trying having some fun sending the text to other people. And as it crashes whoever is receiving this message making it a problem. 

Both of the companies are aware of this issue and most probably dealt with it already, from my point of view, how can I prevent it from happening. How can I predict such things so that it does not happen (or reduces the chance of happening) it the real world. This is an input for me and for the people working on my line. I might not have any exact way to deal with it now, but surely i'll try something different while testing considering these scenarios.