obsolete: fix one-element tuple in module docstring

obsolete: let N denote number of obsoleted changestes in a marker The number of obsoleted changesets is referred to as N later in the docstring.

obsolete: fix language and grammar in module docstring

churn: compute padding with unicode strings Most UTF-8 aware terminals convert multibyte sequences into a single displayed characters. Because the first column is padded by counting bytes, the second column is not perfectly aligned in the presence of non ASCII characters.

Added signature for changeset 564f55b25122

Added tag 3.0-rc for changeset 564f55b25122

merge default into stable for 3.0 code freeze

bundle2: allow extensions to extend the getbundle request We want extensions to be able to request extra parts.

bundle2: add a way to add parts during a `getbundle` request We add a hook function to let extensions add parts to the bundle.

getbundle: pass arbitrary arguments all along the call chain The wireprotocol command accepts arbitrary arguments, we are now passing such arguments down the call chain.

bundle2: call a hook after the transaction is closed We call a dedicated hook right after closing the transaction. This will let people react to the transaction with all the information in hand. This hook is experimental and will not survive in future versions.

bundle2: call a hook prior to closing the transaction We call a dedicated hook right before closing the transaction. This will let people abort unbundling with all the information in hand. This hook is experimental and will not survive in future versions.

bundle2: inform transaction that we are in a bundle2 unbundle That way, hooks called during the unbundle process are aware that a bigger picture is going on.

changegroup: use tr.hookargs when calling changegroup hooks So that other parties using the transaction can put information in our hook calls.

changegroup: use tr.hookargs when calling pretxnchangegroup hooks So that other parties using the transaction can put information in our hook calls.

addchangegroup: register data in tr.hookargs We are registering data related to the process into the transaction hook data. This lets other parties using the same transaction get informed of the addchangegroup result.

transaction: add a notion of hook arguments It is now possible to register parameters to be used when invoking hooks in this transaction. This will cope with the fact that bundle2 adds multiple data types in a single transaction. Do not expect any wide and consistent usages of this in the next release. This will be used by bundle2 experiments first. It will be made better for the release after.

bundle2: allow extensions to plug into the push process Extensions are offered functions to add parts and process their results.

bundle2: require both client and server to opt in Even if the server is bundle2-enabled, the client now has to opt-in in the config too.

bundle2: move bundle2 config option to section "experimental" We highlight the fact that this is experimental by moving it to an "experimental" section, and we match the config name with the server capability name `bundle2-exp`.

bundle2: move all parts into a `bx2` namespace All currently core parts are moved to a `bx2` namespace (for "bundle 2 experimental"). This should avoid conflicts between the final stable format and the one about to be released.

bundle2: rename server capability to bundle2-exp For the same reason, we advertise this bundle2 implementation and format as experimental. This will leave room for field testing in 3.0 but won't conflict with a stable implementation in 3.1.

bundle2: use HG2X in the header The current implementation of bundle2 is still very experimental and the 3.0 freeze is yesterday. The current bundle2 format has never been field-tested, so we rename the header to HG2X. This leaves the HG20 header available for real usage as a stable format in Mercurial 3.1. We won't guarantee that future mercurial versions will keep supporting this `HG2X` format.

bundle2: transmit capabilities to getbundle during pull Bundle2 capabilities of the client are sent to the server in the bundlecaps argument of `getbundle`.

bundle2: include client capabilities in the pushed bundle The necessary data is now included in the `replycaps` part.

bundle2: advertise bundle2 caps in server capabilities We can now retrieve them from the server during push. The capabilities are encoded the same way as in `replycaps` part (with an extra layer of urlquoting to escape separators).

bundle2: add bundle2caps dict on localrepo object This dictionary will hold bundle2-related capabilities.

bundle2: capabilities encoding

bundle2: extract capabilities decoding We'll need to reuse this in more places (at least pull and push).

bundle2: protect capabilities name and values with url quoting This lift limitations of the text based encoding.