tests/test-wireproto-command-pushkey.t

dirstate-tree: Add tree traversal/iteration

Like Python’s, Rust’s iterators are "external" in that they are driven
by a caller who calls a `next` method. This is as opposed to "internal"
iterators who drive themselves and call a callback for each item.

Writing an internal iterator traversing a tree is easy with recursion,
but internal iterators cannot rely on the call stack in that way,
they must save in an explicit object all state that they need to be
preserved across two `next` calls.

This algorithm uses a `Vec` as a stack that contains what would be
local variables on the call stack if we could use recursion.

Differential Revision: https://phab.mercurial-scm.org/D10370

  $ . $TESTDIR/wireprotohelpers.sh

  $ hg init server
  $ enablehttpv2 server
  $ cd server
  $ cat >> .hg/hgrc << EOF
  > [web]
  > push_ssl = false
  > allow-push = *
  > EOF
  $ hg debugdrawdag << EOF
  > C D
  > |/
  > B
  > |
  > A
  > EOF

  $ hg serve -p $HGPORT -d --pid-file hg.pid -E error.log
  $ cat hg.pid > $DAEMON_PIDS

pushkey for a bookmark works

  $ sendhttpv2peer << EOF
  > command pushkey
  >     namespace bookmarks
  >     key @
  >     old
  >     new 426bada5c67598ca65036d57d9e4b64b0c1ce7a0
  > EOF
  creating http peer for wire protocol version 2
  sending pushkey command
  response: True

  $ sendhttpv2peer << EOF
  > command listkeys
  >     namespace bookmarks
  > EOF
  creating http peer for wire protocol version 2
  sending listkeys command
  response: {
    b'@': b'426bada5c67598ca65036d57d9e4b64b0c1ce7a0'
  }

  $ cat error.log