What's a robust way to to read default applications?

[Nate Graham]

Hello all,
I'm working on some code that needs to get the default file manager 
application. I'm currently using KSharedConfig::openConfig to read 
mimeapps.list, which works as long as mimeapps.list exists. But I'm 
noticing that on a fresh install, mimeapps.list doesn't exist--it seems 
to get created only when the user changes something in the 
componentchooser KCM.

So what's the most robust way to read this data?

Nate Graham