documentation: add some internals documentation about bid merge
This is an important algorithm that was only documented on the wiki so far.
Some update to the algorithm (and associated doc) is to expected in the future
since the bid merge algorithm is bug-ridden when it comes to file deletion comes
to play.
Differential Revision: https://phab.mercurial-scm.org/D8711
$ hg init t
$ cd t
$ echo a > a
$ hg add a
$ hg commit -m test
$ rm .hg/requires
$ hg tip
abort: unknown version (2) in revlog 00changelog.i!
[255]
$ echo indoor-pool > .hg/requires
$ hg tip
abort: repository requires features unknown to this Mercurial: indoor-pool!
(see https://mercurial-scm.org/wiki/MissingRequirement for more information)
[255]
$ echo outdoor-pool >> .hg/requires
$ hg tip
abort: repository requires features unknown to this Mercurial: indoor-pool outdoor-pool!
(see https://mercurial-scm.org/wiki/MissingRequirement for more information)
[255]
$ cd ..
Test checking between features supported locally and ones required in
another repository of push/pull/clone on localhost:
$ mkdir supported-locally
$ cd supported-locally
$ hg init supported
$ echo a > supported/a
$ hg -R supported commit -Am '#0 at supported'
adding a
$ echo 'featuresetup-test' >> supported/.hg/requires
$ cat > $TESTTMP/supported-locally/supportlocally.py <<EOF
> from __future__ import absolute_import
> from mercurial import extensions, localrepo
> def featuresetup(ui, supported):
> for name, module in extensions.extensions(ui):
> if __name__ == module.__name__:
> # support specific feature locally
> supported |= {b'featuresetup-test'}
> return
> def uisetup(ui):
> localrepo.featuresetupfuncs.add(featuresetup)
> EOF
$ cat > supported/.hg/hgrc <<EOF
> [extensions]
> # enable extension locally
> supportlocally = $TESTTMP/supported-locally/supportlocally.py
> EOF
$ hg -R supported status
$ hg init push-dst
$ hg -R supported push push-dst
pushing to push-dst
abort: required features are not supported in the destination: featuresetup-test
[255]
$ hg init pull-src
$ hg -R pull-src pull supported
pulling from supported
abort: required features are not supported in the destination: featuresetup-test
[255]
$ hg clone supported clone-dst
abort: repository requires features unknown to this Mercurial: featuresetup-test!
(see https://mercurial-scm.org/wiki/MissingRequirement for more information)
[255]
$ hg clone --pull supported clone-dst
abort: required features are not supported in the destination: featuresetup-test
[255]
$ cd ..