configitems: add a new config option to control new filenode functionality
This series is adding functionality where we can force create a new filenode for
some files on a merge-commit. This is meant to represent an explicit choice made
by user and hence distingusing the file in the merged commit with the file in
parent by creating a new filenode instead of using the parent one.
This introduces a experimental config option under which this functionality
will be hidden.
A new testcase is added in tests/test-merge-criss-cross.t to test the new
functionality while making the option does not break other scenarios.
Differential Revision: https://phab.mercurial-scm.org/D9026
https://bz.mercurial-scm.org/619
$ hg init
$ echo a > a
$ hg ci -Ama
adding a
$ echo b > b
$ hg branch b
marked working directory as branch b
(branches are permanent and global, did you want a bookmark?)
$ hg ci -Amb
adding b
$ hg co -C 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
Fast-forward:
$ hg merge b
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -Ammerge
Bogus fast-forward should fail:
$ hg merge b
abort: merging with a working directory ancestor has no effect
[255]
Even with strange revset (issue4465)
$ hg merge ::.
abort: merging with a working directory ancestor has no effect
[255]