context: make changectx.mutable() benefit from .phase() logic
This fixes "hg qimport -r null". Previous versions used to:
- Traceback because null revision mutability was not defined
- Add an empty -1.diff patch to the series
The error message:
abort: revision -1 is not mutable
is symptomatic of a deeper problem in phase command revision handling. It could
be fixed easily in the command itself but I feel a better fix must be done in
phase API which raises the issue of phase updates atomicity: aborting in
phases.advanceboundary/retractboundary requires a better rollback behaviour to
avoid partial changes.
$ hg init repo
$ cd repo
$ echo line 1 > foo
$ hg ci -qAm 'add foo'
copy foo to bar and change both files
$ hg cp foo bar
$ echo line 2-1 >> foo
$ echo line 2-2 >> bar
$ hg ci -m 'cp foo bar; change both'
in another branch, change foo in a way that doesn't conflict with
the other changes
$ hg up -qC 0
$ echo line 0 > foo
$ hg cat foo >> foo
$ hg ci -m 'change foo'
created new head
we get conflicts that shouldn't be there
$ hg merge -P
changeset: 1:484bf6903104
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: cp foo bar; change both
$ hg merge --debug
searching for copies back to rev 1
unmatched files in other:
bar
all copies found (* = to merge, ! = divergent):
bar -> foo *
checking for directory renames
resolving manifests
overwrite: False, partial: False
ancestor: e6dc8efe11cc, local: 6a0df1dad128+, remote: 484bf6903104
foo: versions differ -> m
foo: remote copied to bar -> m
preserving foo for resolve of bar
preserving foo for resolve of foo
updating: foo 1/2 files (50.00%)
picked tool 'internal:merge' for bar (binary False symlink False)
merging foo and bar to bar
my bar@6a0df1dad128+ other bar@484bf6903104 ancestor foo@e6dc8efe11cc
premerge successful
updating: foo 2/2 files (100.00%)
picked tool 'internal:merge' for foo (binary False symlink False)
merging foo
my foo@6a0df1dad128+ other foo@484bf6903104 ancestor foo@e6dc8efe11cc
premerge successful
0 files updated, 2 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
contents of foo
$ cat foo
line 0
line 1
line 2-1
contents of bar
$ cat bar
line 0
line 1
line 2-2