[MERGE] Fix stacking tests applicability

[John Arbash Meinel]

John Arbash Meinel has voted comment.
Status is now: Semi-approved
Comment:
(sorry, I hit enter by accident)

If I understand correctly, the basic change you made is to switch:
         target = source.bzrdir.sprout('target').open_branch()

so that if it raises UnstackableBranchFormat it translates that error 
into "TestNotApplicable". And you did this for several different tests. 
Is that correct?

IMO, that is not the correct fix. Consider the causes:

1) source.bzrdir.sprout('target')

This doesn't seem like something that should *ever raise 
UnstackableBranchFormat.
If there is a "default_stack_on" policy, but the branch format doesn't 
support
stacking, it should just not stack. And if it does support stacking, 
then
everything should just work.

Note that the individual tests can then later say stuff like
"get_stacked_on_url()" should either raise an exception, or give this 
specific
result. But, IMO, sprout() should not be failing.


2) source.bzrdir.sprout('target').open_branch()

This should *definitely* never raise UnstackableBranchFormat. Once you 
have
created the branch from sprout() you *better* be able to open it. Or we 
have
created something explicitly broken as a result of sprout(). And I would 
*want*
a failing test letting me know that "sprout()" is broken for this 
format.


For details, see: 
http://bundlebuggy.aaronbentley.com/project/bzr/request/%3Cm2vdtgb9pa.fsf%40free.fr%3E
Project: Bazaar