tests: extract the obshistory amend test case into a separate file

tests: extract obshistory setup in a separate file We are gonna soon explode the obshistory test file into several, extract the setup to reuse it as much as possible.

obslog: add a new flag to filter out non-local nodes

compat: drop compatibility hack for mercurial <4.3 We no longer support version prior 4.3.

compat: temporarily move copies fix to compat.py This patch moves a fixed version of copies._fullcopytracing() to compat.py as this was not fixed in core before release and also we need to do this anyway for the older versions of mercurial. This fix is that when base changeset is not ancestor of any of the merging commits, we don't throw an error. The phabricator differential which will fix this in core is https://phab.mercurial-scm.org/D3896. This fixes the traceback we get in previous changeset while relocating one of the content-divergent changeset.

evolve: continue conflicted relocation content-divergence This patch adds logic to continue an conflicted content-divergence resolution which was interrupted while relocating one of the divergent commits. The tests shows the there is some mishandling of copies internally which will be fixed in next patch.

topic: use self instead of repo in topicrepo methods Referring to repo here was somehow preventing it from being garbage-collected (important in hgweb, where currently every request gets a new repo).

evolvecmd: introduce fn to be wrapped by extensions resolving content-div The function added will be used by extension by wrapping it and adding logic to merge data introduced by them. For example: topic extension can wrap this function and add logic to merge topic names.

evolvecmd: move remaining logic to merge commit desc to existing utility fn This was a bit awful because we had a utility function and still we did some of merging outside of that fn. So let's move the remaining parts there.

amend: allow aborting an `amend --patch` by saving an empty file (issue5925) This patch fixes issue5925 by allow aborting a `hg amend --patch` call by saving an empty patch file. This is similar to aborting of `hg amend` when commit message is empty. Test changes demonstrate the fix.

tests: add a test to demonstrate issue5925 The issue will be fixed in next patch.

test: fix possible output change from 4.7 Change in debug timing can display these extra messages.

state: add the get() method that evolvecmd:1836 expects

rewing: prevent rewind in case of uncommitted changes rewind can update, which means merge and troubles. We might relax this limitation in the future.

rewind: default to rewinding the current stack

rewing: add the ability to rewind "from" revisions

evolve: exclude "identical" precursors from the precursors set I'm not sure it is the right thing to do, but it simply thing a lot for now. Otherwise, using 'precursors' to find rewind direction become too complex. This is going to give problematic result in case of prune. Since there are no other precursors to follow.

rewind: move revision selection into its own function This will help making the logic more advanced.

rewind: automatically rewind entire stack We now rewind the full stack, avoiding creating orphans. A `--exact` flag is added to force rewinding only the explicitly specified changesets.

rewind: add a test about rewinding top of stack For now this rewind is creating an orphan. We add the test to check the behavior in that case.

rewind: use rewinded parent when creating multiple changesets Use use the rewinded parent instead of creating orphans based on identical, but obsolete, changesets.

rewind: add a test for rewinding a fold The code already have basic support for case. However the result create orphan that will need to be improved. However, we keep this changeset simple.

rewind: add a test for rewinding a split There are no code change needed but it is worth testing on its own.

rewind: update the working copy if it gets obsoleted If the working copy parent is rewinded, follow the rewind.

rewind: add a message about obsolete changeset Not the best output, but useful to have the data. We can improve that later.

rewind: obsolete latest successors unless instructed otherwise To prevent the creations of divergence, we automatically mark the successors set of the rewinded changeset as obsoleted by the rewind result. A new flag `--as-divergence` is added to disable this behavior.

rewind: test rewinding an amended changesets We are now able to rewind a simple amended changeset. For now, its current successors has not been obsoleted and we created divergence.

rewind: add a message about the rewinded changesets This helps to understand what happened.

rewind: add a proto version of the command This first version focus on rewinding a single revision without care for the consequence.

stablesort: make sure heads are processed in sorted order changeset 72621094505f will fix some ordering issue in the `heads` revset so we stabilise the output in advance.