On Fri 07 Sep 2018 02:42:53 PM CEST, Max Reitz wrote: > The whole purpose of bs->auto_backing_file is so you can compare it > with bs->backing->bs->filename, see when it differs, and then you know > that the user has changed the backing file from what it would be based > on the image header alone (that is, if the user hadn't specified any > @backing option at all). [...] > (Now you could ask yourself, if we know the user hasn't specified any > options to override the backing file -- why don't we just store a > flag? I tried that, Kevin wasn't really happy about it because it's > hard to catch all corner cases. There are many ways to change a > backing file, and if you want to find out when a backing file has been > changed to exactly what the image header says (this is the ideal > outcome of the commit block job, for instance), you basically get back > to the same problem of comparing filenames.)
Ok, I think this clarifies a lot. Thanks! Berto
