largefiles: always create the cache and standin directories when cloning
The standin matcher only works if the .hglf directory exists (and it won't exist
if 'clone -U' is used, unless --all-largefiles is also specified). Since not
even 'update -r null' will get rid of the standin directory, this ensures that
the standin directory always exists if the repo has the 'largefiles'
requirement. This requirement is only set after a largefile is committed, so
these directories will not be created for repos that have the extension enabled
but have not committed a largefile.
With the standin directory in place, 'lfconvert --to-normal' will now be able to
download the required largefiles when converting a repo that was created with
'clone -U', and whose files are not in the usercache.
The downloadlfiles command could probably be put inside the 'largefiles'
requirement conditional too, but given that the user specified --all-largefiles,
there is likely an expectation to print out the number of largefiles downloaded,
even if it is 0.
Test issue2761
$ hg init
$ touch to-be-deleted
$ hg add
adding to-be-deleted
$ hg ci -m first
$ echo a > to-be-deleted
$ hg ci -m second
$ rm to-be-deleted
$ hg diff -r 0
Same issue, different code path
$ hg up -C
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ touch does-not-exist-in-1
$ hg add
adding does-not-exist-in-1
$ hg ci -m third
$ rm does-not-exist-in-1
$ hg diff -r 1