tests/test-narrow-clone-non-narrow-server.t

wireproto: separate commands tables for version 1 and 2 commands

We can't easily reuse existing command handlers for version 2
commands because the response types will be different. e.g. many
commands return nodes encoded as hex. Our new wire protocol is
binary safe, so we'll wish to encode nodes as binary.

We /could/ teach each command handler to look at the protocol
handler and change behavior based on the version in use. However,
this would make logic a bit unwieldy over time and would make
it harder to design a unified protocol handler interface. I think
it's better to create a clean break between version 1 and version 2
of commands on the server.

What I imagine happening is we will have separate @wireprotocommand
functions for each protocol generation. Those functions will parse the
request, dispatch to a common function to process it, then generate
the response in its own, transport-specific manner.

This commit establishes a separate table for tracking version 1
commands from version 2 commands. The HTTP server pieces have been
updated to use this new table.

Most commands are marked as both version 1 and version 2, so there is
little practical impact to this change.

A side-effect of this change is we now rely on transport registration
in wireprototypes.TRANSPORTS and certain properties of the protocol
interface. So a test had to be updated to conform.

Differential Revision: https://phab.mercurial-scm.org/D2982

Test attempting a narrow clone against a server that doesn't support narrowhg.

  $ . "$TESTDIR/narrow-library.sh"

  $ hg init master
  $ cd master

  $ for x in `$TESTDIR/seq.py 10`; do
  >   echo $x > "f$x"
  >   hg add "f$x"
  >   hg commit -m "Add $x"
  > done

  $ hg serve -a localhost -p $HGPORT1 --config extensions.narrow=! -d \
  >    --pid-file=hg.pid
  $ cat hg.pid >> "$DAEMON_PIDS"
  $ hg serve -a localhost -p $HGPORT2 -d --pid-file=hg.pid
  $ cat hg.pid >> "$DAEMON_PIDS"

Verify that narrow is advertised in the bundle2 capabilities:
  $ echo hello | hg -R . serve --stdio | \
  >   $PYTHON -c "from __future__ import print_function; import sys, urllib; print(urllib.unquote_plus(list(sys.stdin)[1]))" | grep narrow
  narrow=v0

  $ cd ..

  $ hg clone --narrow --include f1 http://localhost:$HGPORT1/ narrowclone
  requesting all changes
  abort: server doesn't support narrow clones
  [255]

Make a narrow clone (via HGPORT2), then try to narrow and widen
into it (from HGPORT1) to prove that narrowing is fine and widening fails
gracefully:
  $ hg clone -r 0 --narrow --include f1 http://localhost:$HGPORT2/ narrowclone
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets * (glob)
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd narrowclone
  $ hg tracked --addexclude f2 http://localhost:$HGPORT1/
  comparing with http://localhost:$HGPORT1/
  searching for changes
  looking for local changes to affected paths
  $ hg tracked --addinclude f1 http://localhost:$HGPORT1/
  comparing with http://localhost:$HGPORT1/
  searching for changes
  no changes found
  abort: server doesn't support narrow clones
  [255]