py3: change encoding.localstr to a subclass of bytes, not str

bundle2: relax the condition to update transaction.hookargs This is just a micro optimization. If hookargs is empty, nothing should be necessary.

bundle2: raise ProgrammingError for invalid call of addhookargs() It should be hard error. Also fixed the error message as s/hooks/hookargs/.

merge: removed sorting in casefolding detection, for a slight performance win It was not required for the correctness of the algorithm. Differential Revision: https://phab.mercurial-scm.org/D30

tests: verify that peer instances only expose interface members Our abstract interfaces are more useful if we guarantee that implementations conform to certain rules. Namely, we want to ensure that objects implementing interfaces don't expose new public attributes that aren't part of the interface. That way, as long as consumers don't access "internal" attributes (those beginning with "_") then (in theory) objects implementing interfaces can be swapped out and everything will "just work." We add a test that enforces our "no public attributes not part of the abstract interface" rule. We /could/ implement "interface compliance detection" at run-time. However, that is littered with problems. The obvious solutions are custom __new__ and __init__ methods. These rely on derived types actually calling the parent's implementation, which is no sure bet. Furthermore, __new__ and __init__ will likely be called before instance-specific attributes are assigned. In other words, they won't detect public attributes set on self.__dict__. This means public attribute detection won't be robust. We could work around lack of robust self.__dict__ public attribute detection by having our interfaces implement a custom __getattribute__, __getattr__, and/or __setattr__. However, this incurs an undesirable run-time penalty. And, subclasses could override our custom method, bypassing the check. The most robust solution is a non-runtime test. So that's what this commit implements. We have a generic function for validating that an object only has public attributes defined by abstract classes. Then, we instantiate some peers and verify a newly constructed object plays by the rules. Differential Revision: https://phab.mercurial-scm.org/D339

wireproto: use new peer interface The wirepeer class provides concrete implementations of peer interface methods for calling wire protocol commands. It makes sense for this class to inherit from the peer abstract base class. So we change that. Since httppeer and sshpeer have already been converted to the new interface, peerrepository is no longer adding any value. So it has been removed. httppeer and sshpeer have been updated to reflect the loss of peerrepository and the inheritance of the abstract base class in wirepeer. The code changes in wirepeer are reordering of methods to group by interface. Some Python code in tests was updated to reflect changed APIs. .. api:: peer.peerrepository has been removed. Use repository.peer abstract base class to represent a peer repository. Differential Revision: https://phab.mercurial-scm.org/D338

httppeer: use peer interface This is similar to what we did to sshpeer. Quirks and all. Differential Revision: https://phab.mercurial-scm.org/D337