The new behavior was breaking existing tools that relied on a sequence such as
this:
1) start with a dirty working copy
2) qimport some patch
3) try to qpush it
4) old behavior would fail at this point due to outstanding changes.
(new behavior would only fail if the outstanding changes and the patches
changes intersect)
5) innocent user qrefreshes, gets his local changes in the imported patch
It's worth considering if we can move this behavior to -f in the future.
This patch adds an '--exact/-e' option to qpush that will try to push the
patches in the correct location in the DAG. Specifying this option does the
following:
* If --move is specified, abort. It makes no sense to move a patch to the front
of the queue and try to apply it to its parent, because its parent is one of
the patches we just moved it in front of!
* If patches are already applied, abort. We don't want patch changesets
scattered throughout the DAG.
* If local changes are present, abort unless --force is used, as usual.
* Find the first patch we're going to push (if we're pushing multiple patches
with a target or --all).
* If that patch doesn't have a parent, abort, obviously.
* If the parent doesn't exist in the repo, abort. Something is wrong.
* Update to the parent, then continue pushing the patches as normal.
