scmutil: add option to register summary callbacks as transaction validators
We have a list of summary callbacks which are run after the transaction is
closed to show what has changed and what not. This patch makes it possible to
register those callbacks as transaction validators so that we can show summary
before committing the transaction and prompt user to accept the changes.
The goal of this is to implement `pull --confirm`.
Differential Revision: https://phab.mercurial-scm.org/D8199
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
hgrc
requires
store
Should be empty:
$ ls .hg/store
$ cd ..