bundle2: remove 'experimental.bundle2-exp' boolean config (BC) All users are migrated to 'devel.legacy.exchange', we can clean up the experimental namespace. Marking as (BC) because I know some large installation have bundle2 off and I want to make sure they notice the change.

tests: remove all remaining usage of experimental.bundle2-exp The only remaining usage of the experimental config were enforcing bundle2 on. These are very old remains of when bundle2 was off by default. This was also useful to highlight the fact that this was a bundle2 run and that a bundle1 one was nearby. However, we want a future developer working on bundle3 to notice possible output/behavior change on these tests and take them in account. So we do not enforce bundle2 for these runs. We leave a comment around to make sure dev still notice the bundle1 version.

tests: use 'legacy.exchange' option in various mixed tests The new option will stay around. The experimental option was only meant to be temporary. We update various tests that validate both bundle1 and bundle2 version side by side. This changeset only takes care of enforcing bundle1. The other use of 'experimental.bundle2-exp=True' will be taken care of in the next changeset.

tests: use 'legacy.exchange' option in various bundle1 tests The new option will stay around. The experimental option was only meant to be temporary.

tests: use 'legacy.exchange' option in 'test-bundle2-exchange.t' The new option will stay around. The experimental option was only meant to be temporary.

bundlerepo: also read the 'devel.legacy.exchange' config Bundlerepo does its own bundle2 related logic.

bundle2: add a devel option controling bundle version used for exchange We need an official way to force bundle1 to be used in test. We introduce a new option 'devel.legacy.exchange' to control this. When specified, this option will control the list of bundle version Mercurial consider when exchanging with a peer. Current valid value are 'bundle1' and 'bundle2'. Using this option in all tests will allow us to remove the 'experimental.bundle2-exp' option. We will simplify the code once the experimental option is dropped.

bundle2: rename the _canusebundle2 method to _forcebundle1 We rename and invert the logic of the _canusebundle2 utility. The idea here is that we need to have a way to enforce the use of bundle1 in the tests. The Mercurial philosophy is to try to use the best method available. Currently that best method is bundle2, but this might change in the future. Therefore expressing "do not use bundle2" is a loosy way to say "use bundle 1" and will likely create issue in the future. As the config option will be explicitly about bundle1, we rename the function beforehand to align with this. This will make the life of a future developer working on bundle3 easier.

tests: remove bundle2 activation from test-bookmark-pushpull.t This is an old config that predate bundle2 on by default. This should have been remove after Mercurail 3.6 got released.

tests: update bugzilla link in test-issue1175.t