wireproto: define and implement HTTP handshake to upgrade protocol
When clients connect to repositories over HTTP, they issue a request
to the well-known URL "?cmd=capabilities" to fetch the repository
capabilities. This is the handshake portion of the HTTP protocol.
This commit defines a mechanism to use that HTTP request to return
information about modern server features.
If a client sends an X-HgUpgrade-* header containing a list of
client-supported API names, the server responds with a response
containing information about available services. This includes
the normal capabilities string. So if the server doesn't support
any newer services, the client can easily fall back.
By advertising supported services from clients, server operators
can see and log what client support exists in the wild. This will
also help with debugging.
The response contains the base path to API services. We know there
are potential issues with the <repo>/api/ URL space conflicting with
hgwebdir and subrepos. By making the API URL dynamic from the
perspective of the client, the URL for APIs is not subject to backwards
compatibility concerns - at least as long as a ?cmd=capabilities request
is made.
We've also defined the ``cbor`` client capability for the X-HgProto-*
header. This MUST be sent in order to get the modern response from
"?cmd=capabilities". During implementation, I initially always sent
an application/mercurial-cbor response. However, the handshake
mechanism will be more future compatible if the client is in charge
of which formats to request. We already perform content negotiation
from X-HgProto-*, so keying off this for the capabilities response
feels appropriate.
In addition, I initially used application/cbor. However, it is
conceivable that a non-Mercurial server could serve application/cbor.
To rule out this possibility, I've invented a new media type that
is Mercurial specific and can't be confused for generic CBOR.
Differential Revision: https://phab.mercurial-scm.org/D3242
#require fuzzywuzzy
$ cat >> $HGRCPATH << EOF
> [extensions]
> releasenotes=
> EOF
Bullet point with a single item spanning a single line
$ hg debugparsereleasenotes - << EOF
> New Features
> ============
>
> * Bullet point item with a single line
> EOF
section: feature
bullet point:
paragraph: Bullet point item with a single line
Bullet point that spans multiple lines.
$ hg debugparsereleasenotes - << EOF
> New Features
> ============
>
> * Bullet point with a paragraph
> that spans multiple lines.
> EOF
section: feature
bullet point:
paragraph: Bullet point with a paragraph that spans multiple lines.
$ hg debugparsereleasenotes - << EOF
> New Features
> ============
>
> * Bullet point with a paragraph
> that spans multiple lines.
>
> And has an empty line between lines too.
> With a line cuddling that.
> EOF
section: feature
bullet point:
paragraph: Bullet point with a paragraph that spans multiple lines.
paragraph: And has an empty line between lines too. With a line cuddling that.
Multiple bullet points. With some entries being multiple lines.
$ hg debugparsereleasenotes - << EOF
> New Features
> ============
>
> * First bullet point. It has a single line.
>
> * Second bullet point.
> It consists of multiple lines.
>
> * Third bullet point. It has a single line.
> EOF
section: feature
bullet point:
paragraph: First bullet point. It has a single line.
bullet point:
paragraph: Second bullet point. It consists of multiple lines.
bullet point:
paragraph: Third bullet point. It has a single line.
Bullet point without newline between items
$ hg debugparsereleasenotes - << EOF
> New Features
> ============
>
> * First bullet point
> * Second bullet point
> And it has multiple lines
> * Third bullet point
> * Fourth bullet point
> EOF
section: feature
bullet point:
paragraph: First bullet point
bullet point:
paragraph: Second bullet point And it has multiple lines
bullet point:
paragraph: Third bullet point
bullet point:
paragraph: Fourth bullet point
Sub-section contents are read
$ hg debugparsereleasenotes - << EOF
> New Features
> ============
>
> First Feature
> -------------
>
> This is the first new feature that was implemented.
>
> And a second paragraph about it.
>
> Second Feature
> --------------
>
> This is the second new feature that was implemented.
>
> Paragraph two.
>
> Paragraph three.
> EOF
section: feature
subsection: First Feature
paragraph: This is the first new feature that was implemented.
paragraph: And a second paragraph about it.
subsection: Second Feature
paragraph: This is the second new feature that was implemented.
paragraph: Paragraph two.
paragraph: Paragraph three.
Multiple sections are read
$ hg debugparsereleasenotes - << EOF
> New Features
> ============
>
> * Feature 1
> * Feature 2
>
> Bug Fixes
> =========
>
> * Fix 1
> * Fix 2
> EOF
section: feature
bullet point:
paragraph: Feature 1
bullet point:
paragraph: Feature 2
section: fix
bullet point:
paragraph: Fix 1
bullet point:
paragraph: Fix 2
Mixed sub-sections and bullet list
$ hg debugparsereleasenotes - << EOF
> New Features
> ============
>
> Feature 1
> ---------
>
> Some words about the first feature.
>
> Feature 2
> ---------
>
> Some words about the second feature.
> That span multiple lines.
>
> Other Changes
> -------------
>
> * Bullet item 1
> * Bullet item 2
> EOF
section: feature
subsection: Feature 1
paragraph: Some words about the first feature.
subsection: Feature 2
paragraph: Some words about the second feature. That span multiple lines.
bullet point:
paragraph: Bullet item 1
bullet point:
paragraph: Bullet item 2
Warn user in case of unexpected block while parsing
$ hg init relnotes-warn
$ cd relnotes-warn
$ touch feature1
$ hg -q commit -A -l - << EOF
> commit 1
>
> .. feature::
>
> new feature added.
> some words about the feature.
> EOF
$ hg releasenote -r .
changeset a4251905c440: unexpected block in release notes directive feature
New Features
============
* new feature added. some words about the feature.
$ cd ..