narrow: don't send the changelog information when widening without ellipses When we widen anon-ellipses narrow copy, the server sends the changelog information of all the changesets. The code was copied from ellipses case and in ellipses cases, it's required to send the new changelog data. But in non-ellipses cases, we don't need to send the changelog data as we will have all the changesets locally. Before this patch, there was a overhead of ~8-10 mins on each widening call because of all the changelog information being pulled and being applied. After this patch, we no more pull the changelog information. So this patch can save ~5 mins on Mozilla repo on each widening and more on repos which have more changesets. When we apply an empty changelog from changegroup, there is a devel-warn. This patch kind of hacks to silence that devel-warn. Differential Revision: https://phab.mercurial-scm.org/D4639