tests/test-exchange-obsmarkers-case-B6.t

lfs: autoload the extension when cloning from repo with lfs enabled

This is based on a patch by Gregory Szorc.  I made small adjustments to
clean up the messaging when the server has the extension enabled, but the
client has it disabled (to prevent autoloading).  Additionally, I added
a second server capability to distinguish between the server having the
extension enabled, and the server having LFS commits.  This helps prevent
unnecessary requirement propagation- the client shouldn't add a requirement
that the server doesn't have, just because the server had the extension
loaded.  The TODO I had about advertising a capability when the server can
natively serve up blobs isn't relevant anymore (we've had 2 releases that
support this), so I dropped it.

Currently, we lazily add the "lfs" requirement to a repo when we first
encounter LFS data. Due to a pretxnchangegroup hook that looks for LFS
data, this can happen at the end of clone.

Now that we have more control over how repositories are created, we can
do better.

This commit adds a repo creation option to add the "lfs" requirement.
hg.clone() sets this creation option if the remote peer is advertising
lfs usage (as opposed to just support needed to push).

So, what this change effectively does is have cloned repos
automatically inherit the "lfs" requirement.

Differential Revision: https://phab.mercurial-scm.org/D5130

============================================
Testing obsolescence markers push: Cases B.6
============================================

Mercurial pushes obsolescences markers relevant to the "pushed-set", the set of
all changesets that requested to be "in sync" after the push (even if they are
already on both side).

This test belongs to a series of tests checking such set is properly computed
and applied. This does not tests "obsmarkers" discovery capabilities.

Category B: pruning case
TestCase 6: Pruned changeset with precursors not in pushed set

B.6 Pruned changeset with precursors not in pushed set
======================================================

.. {{{
..   B ø⇠⊗ B'
..     | |
..   A ○ |
..     |/
..     ● O
.. }}}
..
.. Marker exist from:
..
..  * `B ø⇠⊗ B'`
..  * B' prune
..
.. Command run:
..
..  * hg push -r O
..
.. Expected exchange:
..
..  * `B ø⇠⊗ B'`
..  * B' prune

Setup
-----

  $ . $TESTDIR/testlib/exchange-obsmarker-util.sh

Initial

  $ setuprepos B.6
  creating test repo for test case B.6
  - pulldest
  - main
  - pushdest
  cd into `main` and proceed with env setup
  $ cd main
  $ mkcommit A
  $ mkcommit B0
  $ hg up --quiet 0
  $ mkcommit B1
  created new head
  $ hg debugobsolete `getid 'desc(B0)'` `getid 'desc(B1)'`
  obsoleted 1 changesets
  $ hg prune -qd '0 0' .
  $ hg log -G --hidden
  x  f6298a8ac3a4 (draft): B1
  |
  | x  962ecf6b1afc (draft): B0
  | |
  | o  f5bc6836db60 (draft): A
  |/
  @  a9bdc8b26820 (public): O
  
  $ inspect_obsmarkers
  obsstore content
  ================
  962ecf6b1afc94e15c7e48fdfb76ef8abd11372b f6298a8ac3a4b78bbeae5f1d3dc5bc3c3812f0f3 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  f6298a8ac3a4b78bbeae5f1d3dc5bc3c3812f0f3 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  $ cd ..
  $ cd ..

Actual Test
-------------------------------------

  $ dotest B.6 O
  ## Running testcase B.6
  # testing echange of "O" (a9bdc8b26820)
  ## initial state
  # obstore: main
  962ecf6b1afc94e15c7e48fdfb76ef8abd11372b f6298a8ac3a4b78bbeae5f1d3dc5bc3c3812f0f3 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  f6298a8ac3a4b78bbeae5f1d3dc5bc3c3812f0f3 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  # obstore: pushdest
  # obstore: pulldest
  ## pushing "O" from main to pushdest
  pushing to pushdest
  searching for changes
  no changes found
  remote: 2 new obsolescence markers
  ## post push state
  # obstore: main
  962ecf6b1afc94e15c7e48fdfb76ef8abd11372b f6298a8ac3a4b78bbeae5f1d3dc5bc3c3812f0f3 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  f6298a8ac3a4b78bbeae5f1d3dc5bc3c3812f0f3 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  # obstore: pushdest
  962ecf6b1afc94e15c7e48fdfb76ef8abd11372b f6298a8ac3a4b78bbeae5f1d3dc5bc3c3812f0f3 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  f6298a8ac3a4b78bbeae5f1d3dc5bc3c3812f0f3 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  # obstore: pulldest
  ## pulling "a9bdc8b26820" from main into pulldest
  pulling from main
  no changes found
  2 new obsolescence markers
  ## post pull state
  # obstore: main
  962ecf6b1afc94e15c7e48fdfb76ef8abd11372b f6298a8ac3a4b78bbeae5f1d3dc5bc3c3812f0f3 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  f6298a8ac3a4b78bbeae5f1d3dc5bc3c3812f0f3 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  # obstore: pushdest
  962ecf6b1afc94e15c7e48fdfb76ef8abd11372b f6298a8ac3a4b78bbeae5f1d3dc5bc3c3812f0f3 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  f6298a8ac3a4b78bbeae5f1d3dc5bc3c3812f0f3 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  # obstore: pulldest
  962ecf6b1afc94e15c7e48fdfb76ef8abd11372b f6298a8ac3a4b78bbeae5f1d3dc5bc3c3812f0f3 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  f6298a8ac3a4b78bbeae5f1d3dc5bc3c3812f0f3 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}