narrow: when widening, don't include manifests the client already has When widening, we already don't include the changelog (since f1844a10ee19) and files that the client already has (since c73c7653dfb9). However, we still include all manifests needed for the new narrowspec. When using flat manifests, that means we resend all the manifests even though the client necessarily has all of them. For tree manifests, we unnecessarily resend the root manifests and any subdirectory manifests that the client already has. This patch makes it so we no longer resend manifests that the client already has. It does so by passing an extra matcher to the changegroup packer and it uses that for filtering out directories matching the old matcher's visitdir(). For consistency between directories and files, it also makes the filtering of files look at both old and new matcher rather than passing in a diff matcher as we did before. Differential Revision: https://phab.mercurial-scm.org/D4895