But, still I am having a doubt. If, being a developer, someone makes an unintentional mistake & commits the same to SVN, then it will get released in the next Wireshark build. Isn't it? Is there any quality control process / monitoring system for that?
Also, does ViewVc interface make it possible to find all the commits made by a developer? If not, then is it possible some other way?
There isn't really a formal registration process, but registering at http://bugs.wireshark.org/ is a good place to start. As for "tasks" - there isn't a formal list of mandatory activities (but there is a wishlist on the wiki, which might be vaguely interesting); and things are fairly ad-hoc - you just think "I'd like to implement feature X", do it, and post a diff on the bug tracker.
If you think that you're going to do something that conflicts with what others are doing, then it's a good idea to ask on this list, first.