branchcache: add functions to validate changelog nodes This patch adds functions to validate closed nodes, validate nodes for a certain branch and for all the branches. These functions will be used in upcoming patches. Differential Revision: https://phab.mercurial-scm.org/D6207

readline: provide styled prompt to readline (issue6070) Differential Revision: https://phab.mercurial-scm.org/D6168

copies: move comment about implementation of mergecopies() to end When you start reading about mergecopies(), you want to know what it is, not that there are different implementations depending on config, so this patch moves that comment to the end. By the way, we don't seem to define what "copytracing" is. I'm just leaving it that way because I don't know what it is myself. It seems to be referred to only on mergecopies() (and not in pathcopies(), for example), so maybe "copytracing" is supposed to be exactly what mergecopies() does? Differential Revision: https://phab.mercurial-scm.org/D6235

remotefilelog: return expected type from copies overrides copies._computeforwardmissing() and copies._computenonoverlap() return sets, so the overrides should also do that. Differential Revision: https://phab.mercurial-scm.org/D6234

changelog: extract a _string_unescape() to mirror _string_escape() We use our own _string_escape() to encode the "extras" field. Then we use codecs.escape_decode() to escape it. But there's also a little workaround for dealing with escaped text that looks like octal numbers since the fix for https://bz.mercurial-scm.org/show_bug.cgi?id=3156. This patch extracts the call to codecs.escape_decode() along with the fix for octal numbers and puts it in a _string_unescape(). It also updates the test to check for the octal-number case from the aforementioned bug. As you may have suspected, I want to be able to reuse this new function later. Differential Revision: https://phab.mercurial-scm.org/D6184

copies: extract function for deciding whether to use changeset-centric algos We'll eventually have a "experimental.copies.read-from=changeset-only" option too and I don't want to spread the logic for determining if we should use changeset-centric of filelog-centric algorithms. Differential Revision: https://phab.mercurial-scm.org/D6163