cmdstate: introduce a "saver" contextmanager and use it in place of save()
Previously, the state was only saved in some paths out of these functions. This
can be problematic, if the user ctrl-c's (or `kill -9`'s) the process, or we
exit out of `relocate` for anything besides the "expected" reason, we won't
record that we were in the middle of an evolve.
One of our users has discovered that this leaves hg in a weird state; the user
did something like this:
```
$ hg evolve
<something goes wrong with the merge tool, hits ctrl-c>
<deals with the merge conflicts>
$ hg evolve --continue
abort: no interrupted evolve to continue
$ hg evolve
abort: uncommitted changes
# Note: commands.status.verbose=True is set.
$ hg status
M foo
# The repository is in an unfinished *update* state.
# No unresolved merge conflicts
# To continue: hg update
```
The user did an `hg update`, but it didn't actually do anything besides take it
out of the unfinished update state (the files were still dirty in the working
directory).
This test file test the #6028 issue
evolve fails with mercurial.error.ProgrammingError: unsupported changeid '' of type <type 'str'>
https://bz.mercurial-scm.org/show_bug.cgi?id=6028
Global setup
============
$ . $TESTDIR/testlib/common.sh
$ cat >> $HGRCPATH <<EOF
> [ui]
> interactive = true
> [phases]
> publish=False
> [extensions]
> evolve =
> topic =
> EOF
Test
====
$ hg init $TESTTMP/issue-6028
$ cd $TESTTMP/issue-6028
create initial commit
$ echo "0" > 0
$ hg ci -Am 0
adding 0
start new topics "a" and "b" both from 0
$ hg up default
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg topics a
marked working directory as topic: a
$ echo "a" > a
$ hg ci -Am a
adding a
active topic 'a' grew its first changeset
(see 'hg help topics' for more information)
$ hg up default
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg topics b
marked working directory as topic: b
$ echo "b" > b
$ hg ci -Am b
adding b
active topic 'b' grew its first changeset
(see 'hg help topics' for more information)
create branch "integration" from 0, merge topics "a" and "b" into it
$ hg up default
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg branch integration
marked working directory as branch integration
$ hg merge a
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m "merged a"
$ hg merge b
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m "merged b"
commit a bad file on topic "a", merge it into "integration"
$ hg up a
switching to topic a
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo "a bad commit" >> a_bad_commit
$ hg add a_bad_commit
$ hg ci -m "a bad commit"
$ hg up integration
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg merge a
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m "merged a bad commit"
add more commits on both topics and merge them into "integration"
$ hg up a
switching to topic a
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo "aa" >> a
$ hg ci -m "aa"
$ hg up integration
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg merge a
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m "merged aa"
$ hg up b
switching to topic b
0 files updated, 0 files merged, 2 files removed, 0 files unresolved
$ echo "bb" >> b
$ hg ci -m "bb"
$ hg up integration
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg merge b
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m "merged bb"
create instability by pruning two changesets, one in a topic, one a merge
$ hg log -r 5:6 -T '{rev}: {desc}\n'
5: a bad commit
6: merged a bad commit
$ hg prune -r 5:6
2 changesets pruned
3 new orphan changesets
$ hg up 4
2 files updated, 0 files merged, 1 files removed, 0 files unresolved
start the evolve
$ hg evolve --update --no-all
move:[8] merged aa
atop:[4] merged b
working directory is now at c920dd828523
casually checking issue6141: position of p2 is not changed
$ hg log -r 'predecessors(.) + .'
changeset: 8:3f6f25057afb
branch: integration
parent: 6:cfc4c333724f
parent: 7:61eff7f7bb6c
user: test
date: Thu Jan 01 00:00:00 1970 +0000
obsolete: rebased using evolve as 11:c920dd828523
summary: merged aa
changeset: 11:c920dd828523
branch: integration
tag: tip
parent: 4:e33aee2c715e
parent: 7:61eff7f7bb6c
user: test
date: Thu Jan 01 00:00:00 1970 +0000
instability: orphan
summary: merged aa
test that we successfully got rid of the bad file
$ hg d --git -r 'predecessors(.)' -r '.'
diff --git a/a_bad_commit b/a_bad_commit
deleted file mode 100644
--- a/a_bad_commit
+++ /dev/null
@@ -1,1 +0,0 @@
-a bad commit
evolve creates an obsolete changeset above as 11
$ hg evolve -r .
cannot solve instability of c920dd828523, skipping
cannot solve instability of c920dd828523, skipping