lfs: add the ability to disable the usercache
While the usercache is important for real world uses, I've been tripped up more
than a couple of times by it in tests- thinking a file was being downloaded, but
it was simply linked from the local cache. The syntax for setting it is the
same as for setting a null remote endpoint, and like that endpoint, is left
undocumented.
This may or may not be a useful feature in the real world (I'd expect any sane
filesystem to support hardlinks at this point).
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]