Fix pending/update changeset behavior.

Review Request #11795 — Created Aug. 16, 2021 and submitted — Latest diff uploaded

Information

Review Board
release-4.0.x
dbd0725...

Reviewers

ReviewRequest.changeset_is_pending was broken when we did some changes
to the repository/scmtool API, because we neglected to replace the call
to get_scmtool(). This wasn't caught by our existing unit test because
the test was broken in a couple ways (it wasn't properly setting
supports_pending_changesets on the SCMTool class, and the check for
the new commit ID was overwriting the old value and then testing a
variable against itself).

Ran the fixed unit test and saw it fail. Applied the fix and saw all
unit tests succeed.