help: add --system flag to get help for various platform(s)

help: split config user settings file by platform

help: label windows config help

help: split out unix/plan9 config help

help: move config default marking to its own line

help: split config ui.portablefilenames

test-hgignore: add globs for Windows

tests: run check-commit on secret changes too

util: don't capture exception with a name since we don't use it Spotted by pyflakes.

changegroup3: move treemanifest support into _unpackmanifests() By putting the treemanifest code in _unpackmanifests(), _addchangegroupfiles() will only be about files again, and we get a nice symmetry between _packmanifests() and _unpackmanifest(). The immediate benefit to me is that remotefilelog should not need to be updated to work with treemanifests. It should also make server.validate and progress output easier to get right. Probably bundlerepo too.

changegroup3: add empty chunk separating directories and files Remotefilelog overrides changegroup._addchangegroupfiles(), assuming it is about files, which seems like a natural assumption. However, in changegroup3, directory manifests are sent in the files section of the changegroup. These naturally make remotefilelog unhappy. The fact that the directories are not separated from the files (although they do come before the files) also makes server.validate harder to implement. Since we read one chunk at a time from the steam, once we have found a file (non-directory) entry in the stream, we would have to push the read data back into the stream, or otherwise refactor the code. It will be easier if we add an empty chunk after all directory manifests. This change adds that empty chunk, although we don't yet take advantage of it on the reading side. We will soon move the tree manifest stuff out of _addchangegroupfiles() and into _unpackmanifests().

changegroup3: introduce experimental.changegroup3 boolean config In order to give us the freedom to change the changegroup3 format, let's hide it behind an experimental config. Since it is required by treemanifests, that will override the cg3 config.

changegroup: hide packermap behind methods This is to prepare for hiding changegroup3 behind a config option.

merge with stable

context: check for differing flags a little earlier This makes it clearer that a unchanged file whose flags have changed will be reported as a modification. Also test this.

context: clarify why we don't compare file contents when nodeid differs See previous commit for timing information.

status: back out changeset 89f49813526c This backs out 89f49813526c (status: change + back out == clean (API), 2016-01-04). Although correct, it turned out that it was just too slow. For example, 'hg status --rev .~1000 --rev .' on the Mozilla repo went from <1s to >30s on cold disk. So we go back to reporting reverted changes as modified instead of clean. These are rare anyway, as suggested by the fact that it had been broken since before Mercurial 2.0.

rebase: prevent creating divergence Before this patch rebase would create divergence when you were rebasing obsolete changesets on a destination not containing one of its successors. This patch introduces rebase.allowdivergence to explicitly allow divergence creation with rebase.

rebase: create a new variable to make the next patch more legible

rebase: minor refactoring of _computeobsoletenotrebased This patch is a refactoring of the code skipping obsolete changesets already present in destination. It makes the following patches more legible. Instead of passing all the revs to be rebased to _computeobsoletenotrebased, we only pass the obsolete revisions of the rebaseset.

test-status: stabilize for no-execbit platforms The preceding #if conditional was the only modification to the file, so the "reverting file" line in the subsequent revert command was getting dropped.

merge: split up checks for unknown and ignored files that differ In some real-world cases it is preferable to allow overwriting ignored files while continuing to abort on unknown files. This primarily happens when we're replacing build artifacts (which are ignored) with checked in files, but continuing to abort on differing files that aren't ignored. We're redefining merge.checkunknown to only control the behavior for files that aren't ignored. That's fine because this config was only very recently introduced and has not made its way into any Mercurial releases yet.

merge: determine what untracked conflicts cause warns and aborts separately This is written in a somewhat weird style, but it's designed for code reuse in an upcoming patch.

merge: factor out code to get checkunknown config We're going to reuse this code shortly.