dirstate: simplify dirstate's __iter__ Probably also a performance win, but not measurable in perfdirstate. Differential Revision: https://phab.mercurial-scm.org/D269

repo: skip invalidation of changelog if it has 'delayed' changes (API) The changelog object can store recently added revisions in memory until the transaction is committed. We don't want to lose those changes even if repo.invalidate(clearfilecache=True), so let's skip the changelog when it has such 'delayed' changes. Differential Revision: https://phab.mercurial-scm.org/D152

httppeer: make several instance attributes internal (API) Peer instances are supposed to conform to a well-defined API so consumers can be agnostic about the underlying peer type. To reinforce this, this commit renames a handful of instance attributes on httpeer so they no longer have a "public" name. Differential Revision: https://phab.mercurial-scm.org/D268

httppeer: remove unused handler attribute The consumer of this attribute was removed by b6bd4ee6ed85 in 2008. Differential Revision: https://phab.mercurial-scm.org/D267

localrepo: remove unused requirements attributes on localpeer (API) The previous changeset removed the last consumer of requirements. I'm not sure when supportedformats became unused. But I couldn't find any obvious instances where it is being used. It likely stems from peers being derived from repository instances several years ago and is a holdover from that day. Differential Revision: https://phab.mercurial-scm.org/D266

exchange: access requirements on repo instead of peer As part of formalizing the peer interface, I audited for attribute accesses for non-internal names to find API violations. This uncovered the code changed in this commit. localpeer.requirements is just an alias to the repo's requirements attribute. So, change the code to get the data from the source instead of relying on a one-off attribute in the localpeer type. Differential Revision: https://phab.mercurial-scm.org/D265

exchange: drop support for lock-based unbundling (BC) Locking over the wire protocol and the "addchangegroup" wire protocol command has been deprecated since e8c4f3d3df8c, which was first part of Mercurial 0.9.1. Support for handling these commands from sshserver was dropped in 9f6e0e7ef828 in 2015, effectively locking out pre 0.9.1 clients from new servers. However, client-side code for calling lock and addchangegroup is still present in exchange.py and the various peer classes to facilitate pushing to pre 0.9.1 servers. The lock-based pushing mechanism is extremely brittle. 0.9.1 was released in July 2006 and I highly doubt anyone is still running such an ancient version of Mercurial on a server. I'm about to refactor the peer API and I don't think it is worth keeping support for this ancient protocol feature. So, this commit removes client support for the lock-based pushing mechanism. This means modern clients will no longer be able to push to pre 0.9.1 servers. Differential Revision: https://phab.mercurial-scm.org/D264