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).
=====================
Test workflow options
=====================
$ . "$TESTDIR/testlib/topic_setup.sh"
$ . "$TESTDIR/testlib/common.sh"
Test single head enforcing - Setup
=============================================
$ hg init single-head-server
$ cd single-head-server
$ cat <<EOF >> .hg/hgrc
> [phases]
> publish = no
> [experimental]
> enforce-single-head = yes
> evolution = all
> EOF
$ mkcommit ROOT
$ mkcommit c_dA0
$ cd ..
$ hg clone single-head-server client
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
Test single head enforcing - with branch only
---------------------------------------------
$ cd client
continuing the current defaultbranch
$ mkcommit c_dB0
$ hg push
pushing to $TESTTMP/single-head-server
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
creating a new branch
$ hg up 'desc("ROOT")'
0 files updated, 0 files merged, 2 files removed, 0 files unresolved
$ hg branch branch_A
marked working directory as branch branch_A
(branches are permanent and global, did you want a bookmark?)
$ mkcommit c_aC0
$ hg push --new-branch
pushing to $TESTTMP/single-head-server
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
Create a new head on the default branch
$ hg up 'desc("c_dA0")'
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ mkcommit c_dD0
created new head
(consider using topic for lightweight branches. See 'hg help topic')
$ hg push -f
pushing to $TESTTMP/single-head-server
searching for changes
adding changesets
adding manifests
adding file changes
transaction abort!
rollback completed
abort: 2 heads on "default"
(286d02a6e2a2, 9bf953aa81f6)
[255]
remerge them
$ hg merge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ mkcommit c_dE0
$ hg push
pushing to $TESTTMP/single-head-server
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 2 files
Test single head enforcing - with topic
---------------------------------------
pushing a new topic
$ hg topic foo
marked working directory as topic: foo
$ mkcommit c_dF0
active topic 'foo' grew its first changeset
(see 'hg help topics' for more information)
$ hg push
pushing to $TESTTMP/single-head-server
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
pushing a new topo branch (with a topic)
$ hg up 'desc("c_dD0")'
0 files updated, 0 files merged, 3 files removed, 0 files unresolved
$ hg topic bar
marked working directory as topic: bar
$ mkcommit c_dG0
active topic 'bar' grew its first changeset
(see 'hg help topics' for more information)
$ hg push
pushing to $TESTTMP/single-head-server
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
detect multiple heads on the topic
$ mkcommit c_dH0
$ hg push
pushing to $TESTTMP/single-head-server
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
$ hg up 'desc("c_dG0")'
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ mkcommit c_dI0
$ hg push -f
pushing to $TESTTMP/single-head-server
searching for changes
adding changesets
adding manifests
adding file changes
transaction abort!
rollback completed
abort: 2 heads on "default:bar"
(5194f5dcd542, 48a01453c1c5)
[255]
merge works fine
$ hg merge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ mkcommit c_dJ0
$ hg push
pushing to $TESTTMP/single-head-server
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 2 files
Test single head enforcing - by phase move
------------------------------------------
$ hg -R ../single-head-server phase --public 'desc("c_dJ0")'
abort: 2 heads on "default"
(6ed1df20edb1, 678bca4de98c)
[255]
Test single head enforcing - after rewrite
------------------------------------------
$ hg up foo
switching to topic foo
3 files updated, 0 files merged, 4 files removed, 0 files unresolved
$ hg commit --amend -m c_dF1
$ hg push
pushing to $TESTTMP/single-head-server
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 0 changes to 1 files (+1 heads)
1 new obsolescence markers
obsoleted 1 changesets