Closing streams in the destructor

[Navin Gupta]

In mailnews code there are several instances of opening a new 
nsInputFileStream and/or nsOutputFileStream and then just deleting the
stream without closing it. One alternative would be to search for all 
such instances in our codebase and close them. Another, less tedious 
alternative would be to close the stream in it's destructor. Is it a 
good programming practice to close the stream in the destructor ?

thanks,

Navin