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
Tests for access level on hidden commits by various commands on based of their
type.
Setting the required config to start this
$ cat >> $HGRCPATH <<EOF
> [experimental]
> evolution=createmarkers, allowunstable
> directaccess=True
> directaccess.revnums=True
> [extensions]
> amend =
> EOF
$ hg init repo
$ cd repo
$ for ch in a b c; do touch $ch; echo "foo" >> $ch; hg ci -Aqm "Added "$ch; done
$ hg log -G -T '{rev}:{node} {desc}' --hidden
@ 2:28ad74487de9599d00d81085be739c61fc340652 Added c
|
o 1:29becc82797a4bc11ec8880b58eaecd2ab3e7760 Added b
|
o 0:18d04c59bb5d2d4090ad9a5b59bd6274adb63add Added a
$ echo "bar" >> c
$ hg amend
$ hg log -G -T '{rev}:{node} {desc}' --hidden
@ 3:2443a0e664694756d8b435d06b6ad84f941b6fc0 Added c
|
| x 2:28ad74487de9599d00d81085be739c61fc340652 Added c
|/
o 1:29becc82797a4bc11ec8880b58eaecd2ab3e7760 Added b
|
o 0:18d04c59bb5d2d4090ad9a5b59bd6274adb63add Added a
Testing read only commands on the hidden revision
Testing with rev number
$ hg exp 2 --config experimental.directaccess.revnums=False
abort: hidden revision '2' was rewritten as: 2443a0e66469!
(use --hidden to access hidden revisions)
[255]
$ hg exp 2
# HG changeset patch
# User test
# Date 0 0
# Thu Jan 01 00:00:00 1970 +0000
# Node ID 28ad74487de9599d00d81085be739c61fc340652
# Parent 29becc82797a4bc11ec8880b58eaecd2ab3e7760
Added c
diff -r 29becc82797a -r 28ad74487de9 c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/c Thu Jan 01 00:00:00 1970 +0000
@@ -0,0 +1,1 @@
+foo
$ hg log -r 2
changeset: 2:28ad74487de9
user: test
date: Thu Jan 01 00:00:00 1970 +0000
obsolete: rewritten using amend as 3:2443a0e66469
summary: Added c
$ hg identify -r 2
28ad74487de9
$ hg status --change 2
A c
$ hg status --change 2 --config experimental.directaccess.revnums=False
abort: hidden revision '2' was rewritten as: 2443a0e66469!
(use --hidden to access hidden revisions)
[255]
$ hg diff -c 2
diff -r 29becc82797a -r 28ad74487de9 c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/c Thu Jan 01 00:00:00 1970 +0000
@@ -0,0 +1,1 @@
+foo
Testing with hash
`hg export`
$ hg exp 28ad74
# HG changeset patch
# User test
# Date 0 0
# Thu Jan 01 00:00:00 1970 +0000
# Node ID 28ad74487de9599d00d81085be739c61fc340652
# Parent 29becc82797a4bc11ec8880b58eaecd2ab3e7760
Added c
diff -r 29becc82797a -r 28ad74487de9 c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/c Thu Jan 01 00:00:00 1970 +0000
@@ -0,0 +1,1 @@
+foo
`hg log`
$ hg log -r 28ad74
changeset: 2:28ad74487de9
user: test
date: Thu Jan 01 00:00:00 1970 +0000
obsolete: rewritten using amend as 3:2443a0e66469
summary: Added c
`hg cat`
$ hg cat -r 28ad74 c
foo
`hg diff`
$ hg diff -c 28ad74
diff -r 29becc82797a -r 28ad74487de9 c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/c Thu Jan 01 00:00:00 1970 +0000
@@ -0,0 +1,1 @@
+foo
`hg files`
$ hg files -r 28ad74
a
b
c
`hg identify`
$ hg identify -r 28ad74
28ad74487de9
`hg annotate`
$ hg annotate -r 28ad74 a
0: foo
`hg status`
$ hg status --change 28ad74
A c
`hg archive`
This should not throw error
$ hg archive -r 28ad74 foo
`hg update`
$ hg up 28ad74
updating to a hidden changeset 28ad74487de9
(hidden revision '28ad74487de9' was rewritten as: 2443a0e66469)
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg up 3
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg up
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
`hg revert`
$ hg revert -r 28ad74 --all
reverting c
$ hg diff
diff -r 2443a0e66469 c
--- a/c Thu Jan 01 00:00:00 1970 +0000
+++ b/c Thu Jan 01 00:00:00 1970 +0000
@@ -1,2 +1,1 @@
foo
-bar
Test special hash/rev
$ hg log -qr 'null:wdir() & 000000000000'
-1:000000000000
$ hg log -qr 'null:wdir() & ffffffffffff'
2147483647:ffffffffffff
$ hg log -qr 'null:wdir() & rev(-1)'
-1:000000000000
$ hg log -qr 'null:wdir() & rev(2147483647)'
2147483647:ffffffffffff
$ hg log -qr 'null:wdir() & 2147483647'
2147483647:ffffffffffff
Commands with undefined cmdtype should not work right now
$ hg phase -r 28ad74
abort: hidden revision '28ad74' was rewritten as: 2443a0e66469!
(use --hidden to access hidden revisions)
[255]
$ hg phase -r 2
abort: hidden revision '2' was rewritten as: 2443a0e66469!
(use --hidden to access hidden revisions)
[255]
Setting a bookmark will make that changeset unhidden, so this should come in end
$ hg bookmarks -r 28ad74 book
bookmarking hidden changeset 28ad74487de9
(hidden revision '28ad74487de9' was rewritten as: 2443a0e66469)
$ hg bookmarks
book 2:28ad74487de9