Summary: This change enables "allowunstable" for the `hg rebase` command, which lets it create unstable changesets without full evolution enabled.
Test Plan: Create a stack of commits and attempt to rebase a commit in the middle of the stack, using a command like `hg rebase -r REV1 -d REV2` without the `--keep` flag. This will now work, and the old version of the rebased commit (with descendants) will render as an X in smartlog.
Reviewers: #sourcecontrol, quark, durham
Reviewed By: durham
Subscribers: mjpieters
Differential Revision: https://phabricator.intern.facebook.com/D4287989
Signature: t1:4287989:1481074215:80103f6bfd150e51cc152bc257146d3f9369b175
Summary: Currently, the reason we can't perform operations such as histedit, split, and fold in the middle of a stack is that we do not have the experimental.evolution=allowunstable option enabled. It turns out all of these commands will do the "right thing" if this option is enabled. However, since we are uncertain of the ramifications of enabling this option globally, this new extension turns the option on for the duration of split, fold, and histedit, allowing those commands to be used in the middle of a stack without config changes.
Test Plan: See unit tests. Basically, create a stack and then attempt to use split, fold, or histedit somewhere in the middle.
Reviewers: #mercurial, durham
Reviewed By: durham
Subscribers: mjpieters, #sourcecontrol
Differential Revision: https://phabricator.intern.facebook.com/D4209315
Tasks: 14598405
Signature: t1:4209315:1479744780:811e8bef02149a055376c0f105ac2d389dd60970
