evolve: handle relocation during divergence resolution producing no changes
When resolving divergence and the two divergent commits have different
parents, we start by rebasing one of them to have the same parent as
the other. That step can result in no changes to commit. When it does,
we would crash with a TypeError before this patch.
This patch fixes it by instead creating an empty commit in that
scenario. The existing code then continues to attempt to merge it,
which produces no changes, and no commit is created on top. The other
side of the divergence is marked as successor as usual, so orphans
from the side that became empty will be evolved to the right place
(see test).
====================================
Testing head checking code: Case B-1
====================================
Mercurial checks for the introduction of new heads on push. Evolution comes
into play to detect if existing branches on the server are being replaced by
some of the new one we push.
This case is part of a series of tests checking this behavior.
Category B: simple case involving pruned changesets
TestCase 1: single pruned changeset
.. old-state:
..
.. * 1 changeset branch
..
.. new-state:
..
.. * old branch is pruned
.. * 1 new unrelated branch
..
.. expected-result:
..
.. * push allowed
..
.. graph-summary:
..
.. ◔ B
.. |
.. A ⊗ |
.. |/
.. ●
$ . $TESTDIR/testlib/push-checkheads-util.sh
Test setup
----------
$ mkdir B1
$ cd B1
$ setuprepos
creating basic server and client repo
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd client
$ hg up 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ mkcommit B0
created new head
$ hg debugobsolete --record-parents `getid "desc(A0)"`
1 new obsolescence markers
obsoleted 1 changesets
$ hg log -G --hidden
@ 74ff5441d343 (draft): B0
|
| x 8aaa48160adc (draft): A0
|/
o 1e4be0697311 (public): root
Actual testing
--------------
$ hg push
pushing to $TESTTMP/B1/server (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
1 new obsolescence markers
obsoleted 1 changesets
$ cd ../..