lfs: override walk() in lfsvfs
In order to fix the missing lfs store after an upgrade, I attempted to walk the
store vfs to hardlink to the upgraded repo's store. But the custom join()
clashes with the default walk() implementation. First, 'path=None' blew up in
the regex matcher, because it wanted a string. But even if that is fixed, the
join to walk the root of the vfs wouldn't match the required xx/xx...xx pattern.
The first cut of this was a copy/paste/tweak of the base implementation, but
this version of walk() hides the internal directories, and treats the vfs as a
flat store. I think this makes sense because most vfs methods call join() on
input paths, which wants the simple oid format. It also relieves the caller
from having to deal with bogus files/directories in the store.
A repo with unknown revlogv2 requirement string cannot be opened
$ hg init invalidreq
$ cd invalidreq
$ echo exp-revlogv2.unknown >> .hg/requires
$ hg log
abort: repository requires features unknown to this Mercurial: exp-revlogv2.unknown!
(see https://mercurial-scm.org/wiki/MissingRequirement for more information)
[255]
$ cd ..
Can create and open repo with revlog v2 requirement
$ cat >> $HGRCPATH << EOF
> [experimental]
> revlogv2 = enable-unstable-format-and-corrupt-my-data
> EOF
$ hg init empty-repo
$ cd empty-repo
$ cat .hg/requires
dotencode
exp-revlogv2.0
fncache
store
$ hg log
Unknown flags to revlog are rejected
>>> with open('.hg/store/00changelog.i', 'wb') as fh:
... fh.write('\x00\x04\xde\xad')
$ hg log
abort: unknown flags (0x04) in version 57005 revlog 00changelog.i!
[255]
$ cd ..
Writing a simple revlog v2 works
$ hg init simple
$ cd simple
$ touch foo
$ hg -q commit -A -m initial
$ hg log
changeset: 0:96ee1d7354c4
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: initial
Header written as expected (changelog always disables generaldelta)
$ f --hexdump --bytes 4 .hg/store/00changelog.i
.hg/store/00changelog.i:
0000: 00 01 de ad |....|
$ f --hexdump --bytes 4 .hg/store/data/foo.i
.hg/store/data/foo.i:
0000: 00 03 de ad |....|