discovery: limit 'all local heads known remotely' to real 'all' (issue4438) 3ef893520a85 made it possible that the initial head check didn't include all heads. If that is the case, don't use the early exit just because this random sample happened to be 'all known'. Note: the randomness in the discovery protocol can make this problem hard to reproduce.

largefiles: avoid printing messages while rebasing by "_lfstatuswriters" Putting "lambda *msg, **opts: None" (= avoid printing messages always) into "_lfstatuswriters" while rebasing makes explicit passing "printmessage = False" for "updatelfiles()" useless. This patch also removes setting/unsetting "repo._isrebasing" in "overriderebase", because there is no code path referring it.

largefiles: get function to write status messages via "getstatuswriter()" This patch makes "updatelfiles()" get appropriate function to write largefiles specific status messages via "getstatuswriter()". This patch introduces None as "print messages if needed", because True (forcibly writing) and False (forcibly ignoring) are already used for "printmessage" of "updatelfiles". Subsequent patch will move "avoid printing messages only while automated committing" decision from caller of "updatelfiles()" into "getstatuswriter()".

largefiles: introduce "_lfstatuswriters" to customize status reporting "lfutil.getstatuswriter" is the utility to get appropriate function to write largefiles specific status out from "repo._lfstatuswriters". This patch uses "stack" with an element instead of flag like "_isXXXXing" or so, because: - the former works correctly even when customizations are nested, and - ensuring at least one element can ignore empty check