dirstate: narrow gathering of parent data
The parent data are only going to be useful is the file might be clean. And it
might only be clean if it is tracked in both p1 and the working copy.
Differential Revision: https://phab.mercurial-scm.org/D11584
$ 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
unmatched files in other:
bar
all copies found (* = to merge, ! = divergent, % = renamed and deleted):
on remote side:
src: 'foo' -> dst: 'bar' *
checking for directory renames
resolving manifests
branchmerge: True, force: False, partial: False
ancestor: e6dc8efe11cc, local: 6a0df1dad128+, remote: 484bf6903104
starting 4 threads for background file closing (?)
preserving foo for resolve of bar
preserving foo for resolve of foo
bar: remote copied from foo -> m (premerge)
picked tool ':merge' for bar (binary False symlink False changedelete False)
merging foo and bar to bar
my bar@6a0df1dad128+ other bar@484bf6903104 ancestor foo@e6dc8efe11cc
premerge successful
foo: versions differ -> m (premerge)
picked tool ':merge' for foo (binary False symlink False changedelete 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
$ cd ..