upgrade: speed up when we have only nodemap to downgrade
Similar to what we do on upgrade, if we have only persistent-nodemap to
downgrade we will just delete the nodemap files and update repository
requirements instead of processing all the revlogs.
After downgrade, we are left with unrequired docket and transaction files which
seems fine but can work on deleting them if someone feels we should.
Differential Revision: https://phab.mercurial-scm.org/D9992
Create an empty repo:
$ hg init a
$ cd a
Try some commands:
$ hg log
$ hg grep wah
[1]
$ hg manifest
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 0 changesets with 0 changes to 0 files
Check the basic files created:
$ ls .hg
00changelog.i
cache
requires
store
wcache
Should be empty:
$ ls .hg/store
Poke at a clone:
$ cd ..
$ hg clone a b
updating to branch default
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd b
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 0 changesets with 0 changes to 0 files
$ ls .hg
00changelog.i
cache
hgrc
requires
store
Should be empty:
$ ls .hg/store
$ cd ..