ui: add support for a tweakdefaults knob
We've been talking for years about a one-stop config knob to opt in to
better behavior. There have been a lot of ideas thrown around, but
they all seem to be too complicated to get anyone to actually do the
work.. As such, this patch is the stupidest thing that can possibly
work in the name of getting a good feature to users.
Right now it's just three config settings that I think are generally
uncontroversial, but I expect to add more soon. That will likely
include adding new config knobs for the express purpose of adding them
to tweakdefaults.
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 |....|