narrow: move .hg/narrowspec to .hg/store/narrowspec (BC) The narrowspec is more closely related to the store than to the working copy. For example, if the narrowspec changes, the set of revlogs also needs to change (the working copy may change, but that depends on which commit is checked out). Also, when using the share extension, the narrowspec needs to be shared along with the store. This patch therefore moves the narrowspec into the store/ directory. This is clearly a breaking change, but I haven't bothered trying to fall back to reading the narrowspec from the old location (.hg/), because there are very few users of narrow out there. (We'll add a temporary hack to our Google-internal extension to handle the migration.) Differential Revision: https://phab.mercurial-scm.org/D4099

narrow: drop checkambig=True when restoring backup IIUC, checkambig is about updating timestamps of the file while renaming. That's important for the dirstate, but we never check the timestamp of the narrowspec file. We can therefore avoid checking passing checkambig=True. Differential Revision: https://phab.mercurial-scm.org/D4098

narrow: remove a repo file-cache invalidation It's unclear why this was needed. All tests pass without it. I asked Kyle Lippincott (who added the check) and he also doesn't remember what it was for. Differential Revision: https://phab.mercurial-scm.org/D4097

narrow: call narrowspec.{save,restore,clear}backup directly I want to move .hg/narrowspec to .hg/store/narrowspec and we need to decouple the narrowspec update from the dirstate update for that. This patch lets the callers call the narrowspec backup functions directly, in addition to the dirstate backup functions. The narrowspec methods are made to check if narrowing is enabled. For that, a repo instance was needed, which all the callers luckily already had available. Differential Revision: https://phab.mercurial-scm.org/D4096