On 12/13/2017 1:05 PM, Achim Gratz wrote:
> Ken Brown writes:
>> 1. Uninstall A.
>> 2. Don't uninstall B.
>>
>> On the surface, it would seem that libsolv chose 2 by default, because
>> it returned an empty transaction list.  This was reflected in the log
>> and was also clear when I selected 'Back'.
> 
> I don't think there is a default in this case.  I also see in zypper
> that the order of the proposed solutions (there can be way more than two
> if the dependencies are more complicated) is not always the same, so
> there is no preference implied by the order as well.
> 
>> Maybe we have to deal with this situation ourselves.  Whenever a
>> problem involves a missing dependency, we could choose as default
>> solution the one that installs/keeps the dependent package, as is
>> currently done.
> 
> That solution unfortunately isn't always the one that causes the least
> amount of transactions or even the least amount of breakage.

That may be true, but I still think it's a reasonable default.  The user 
doesn't have to accept it.  Also, it's consistent with what setup 
currently does, so it won't surprise anyone.

The attached patch attempts to implement my suggestion.

Ken