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).
Content divergence and trying to relocate a node on top of itself (issue5958)
https://bz.mercurial-scm.org/show_bug.cgi?id=5958
$ . $TESTDIR/testlib/common.sh
$ cat << EOF >> $HGRCPATH
> [extensions]
> rebase =
> evolve =
> EOF
$ hg init issue5958
$ cd issue5958
$ echo hi > r0
$ hg ci -qAm 'add r0'
$ echo hi > foo.txt
$ hg ci -qAm 'add foo.txt'
$ hg metaedit -r . -d '0 2'
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
(Make changes in unrelated files so that we don't have any merge conflicts
during the rebase, but the two touched revisions aren't identical)
$ echo hi > bar.txt
$ hg add -q bar.txt
$ hg amend -q
$ hg metaedit -r 1 -d '0 1' --hidden
2 new content-divergent changesets
$ hg log -r tip
changeset: 4:c17bf400a278
tag: tip
parent: 0:a24ed8ad918c
user: test
date: Wed Dec 31 23:59:59 1969 -0000
instability: content-divergent
summary: add foo.txt
$ echo hi > baz.txt
$ hg add -q baz.txt
$ hg amend -q
$ hg rebase -qr tip -d 4
$ hg log -G
@ changeset: 6:08bc7ba82799
| tag: tip
| parent: 4:c17bf400a278
| user: test
| date: Wed Dec 31 23:59:58 1969 -0000
| instability: content-divergent
| summary: add foo.txt
|
* changeset: 4:c17bf400a278
| parent: 0:a24ed8ad918c
| user: test
| date: Wed Dec 31 23:59:59 1969 -0000
| instability: content-divergent
| summary: add foo.txt
|
o changeset: 0:a24ed8ad918c
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add r0
$ hg debugobsolete
cc71ffbc7c002d7b45fb694f9c060bf2e6920672 0065551bd38fe59ea4a069a4db378550c60122d3 0 (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '32', 'operation': 'metaedit', 'user': 'test'}
0065551bd38fe59ea4a069a4db378550c60122d3 a25dd7af6cf6731ff93708abb2b1b889eae848a0 0 (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '8', 'operation': 'amend', 'user': 'test'}
cc71ffbc7c002d7b45fb694f9c060bf2e6920672 c17bf400a2782394b1ca5fbbe59e30494f16dfdc 0 (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '32', 'operation': 'metaedit', 'user': 'test'}
a25dd7af6cf6731ff93708abb2b1b889eae848a0 1d1fc409af989f5c0843507e202d69a1ad16c5ef 0 (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '8', 'operation': 'amend', 'user': 'test'}
1d1fc409af989f5c0843507e202d69a1ad16c5ef 08bc7ba82799f1e419190b0dac1b0e1c4b1355f9 0 (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '12', 'operation': 'rebase', 'user': 'test'}
$ hg obslog -a -r .
@ 08bc7ba82799 (6) add foo.txt
|
| * c17bf400a278 (4) add foo.txt
| |
x | 1d1fc409af98 (5) add foo.txt
| | rewritten(parent, content) as 08bc7ba82799 using rebase by test (Thu Jan 01 00:00:00 1970 +0000)
| |
x | a25dd7af6cf6 (3) add foo.txt
| | amended(content) as 1d1fc409af98 using amend by test (Thu Jan 01 00:00:00 1970 +0000)
| |
x | 0065551bd38f (2) add foo.txt
|/ amended(content) as a25dd7af6cf6 using amend by test (Thu Jan 01 00:00:00 1970 +0000)
|
x cc71ffbc7c00 (1) add foo.txt
date-changed(date) as 0065551bd38f using metaedit by test (Thu Jan 01 00:00:00 1970 +0000)
date-changed(date) as c17bf400a278 using metaedit by test (Thu Jan 01 00:00:00 1970 +0000)
$ hg evolve --content-divergent
merge:[6] add foo.txt
with: [4] add foo.txt
base: [1] add foo.txt
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
1 new orphan changesets
working directory is now at 8b11b92203c7