localrepo: have stream_in() not modify its argument Localrepo's stream_in function modified its requirements argument. This is not good practice because it may be unexpected behavior to the caller.

localrepo: make _applyrequirements more specific Localrepo's _applyrequirements function isn't very straightforward about what it does. Its purpose is to both act as a setter for the requirements attribute, and to apply appropriate requirements to the opener's configuration. This change makes the function just focus on the latter responsibility. We rename it as such, and make setting the requirements attribute the responsibility of the caller.

localrepo: make requirements always be a set in localrepo.__init__ The init function used to create a local list, and then convert it to a set before assigning it as a data attribute. This change simplifies the function by having it always be a set, requiring no conversion.

localrepo: eliminate requirements class variable (API) Localrepo's requirements class variable was introduced in b090601a80d1 to make requirements modifiable by extensions. A main access point, _baserequirements, still exists, but this change undoes making the class variable to begin with. Without this simplification, there is a class variable with a default value that is only copied, but never directly used. This behavior is moved directly into the _baserequirements function.

changegroup.group: drop 'reorder' parameter Since we always pass self._reorder to self.group(), let's drop the parameter and let group() read from self._reorder itself. There are no other in-tree callers to group().

cg2packer: set reorder=False in __init__ instead of in group() The difference between reorder=None (bundle.reorder=auto) and reorder=False is that the generaldelta revlogs get reordered with the former. In cg2packer, group() we check if the revlog uses generaldelta and if reorder=None and then convert that to reorder=False. We are effectively saying that whether or not generaldelta is used, we want reorder=None to mean reorder=False for changegroup 2. To make this clearer, check if reorder=None in the constructor and change it to False there and drop the overriding of group(). Also document the reason for turning reordering off.