About merging

[tnorth at bluewin.ch]

Hi,
First sorry for this email, it's not about bazaar-ng devel. So if you are
in a hurry, just ignore that.

I would like to know how merging works. I understand a merge between two
branches tries to put together two different versions of a file.
But in most cases, functions have changed, function prototypes aren't the
same anymore, etc.
So the "merge" should most of the time just fail and let a big piece of work
for the guy how merged. 

In fact, I cannot well understand when merging may be an amazing way to put
a stable and unstable version together...

Could someone please tell me what I didn't understand ? I never tried to
merge anything with any SCM, so no idea what may happen... if I try it with
bzr and it fails, may I know where ?

Thanks,
TNorth