changegroup: add functionality to skip adding changelog data to changegroup In narrow extension, when we have a non-ellipses narrow working copy and we extend it, we pull all the changelog data again and the client tries to reapply all that changelog data. While downloading millions of changeset data is still not very expensive but applying them on the client side is very expensive and takes ~10 minutes. These 10 minutes are added to every `hg tracked --addinclude <>` call and extending a narrow copy becomes very slow. This patch adds a new changelog argument to cgpacker.generate() fn. If the changelog argument is set to False, we won't yield the changelog data. We still have to iterate over the deltas returned by _generatechangelog() because that's a generator and builds the data for clstate variable which is required for calculating manifests and filelogs. Differential Revision: https://phab.mercurial-scm.org/D4638

tests: add debug output in test-narrow-widen-no-ellipsis.t This will help us in understanding the upcoming patches better. Differential Revision: https://phab.mercurial-scm.org/D4637

changegroup: improve the devel-warn to specify changelog was empty Right now, the develwarn says "applied empty changegroup" which is not correct because we can send a changegroup without changelog with just manifest and filelogs and it will still say the same. Let's fix this to say that we are applying empty changelog from changegroup. In future patches I am will be adding functionality to send a changegroup from the server without an empty changelog. Differential Revision: https://phab.mercurial-scm.org/D4636

zsh_completion: add -b/--branch and -B/--bookmark(s) flags properly _hg_branch_bmark_opts used to add these two flags, but had the same descriptions for the flags regardless of what command took them and didn't allow specifying flags more than once (no '*' at the start). Even more importantly, it assumed that -B was always expecting an argument (i.e. --bookmark=foo), but in case of incoming and outgoing it's not so (--bookmarks is self-sufficient). Differential Revision: https://phab.mercurial-scm.org/D4612