[MERGE][0.16] Allow new smart client to work with old (<= 0.15) smart servers.

[Andrew Bennetts]

Andrew Bennetts wrote:
> After a suggestion from Robert, this bundle will allow the new hpss clients to
[...]

I totally hit the attach button, and mutt just wants to spite me.  Either that,
or I was distracted by the imminent dinner...

Here's the belated bundle.

-Andrew.

-------------- next part --------------
# Bazaar revision bundle v0.9
#
# message:
#   Try a version 1 hello probe to determine if we can use RemoteBzrDir on a particular transport, allowing smooth interoperation with older servers.
# committer: Andrew Bennetts <andrew.bennetts at canonical.com>
# date: Tue 2007-04-24 20:25:46.566999912 +1000

=== modified file bzrlib/bzrdir.py
--- bzrlib/bzrdir.py
+++ bzrlib/bzrdir.py
@@ -57,6 +57,7 @@
     sha_string,
     )
 from bzrlib.smart.client import _SmartClient
+from bzrlib.smart import protocol
 from bzrlib.store.revision.text import TextRevisionStore
 from bzrlib.store.text import TextStore
 from bzrlib.store.versioned import WeaveStore
@@ -2232,12 +2233,20 @@
     def probe_transport(klass, transport):
         """Return a RemoteBzrDirFormat object if it looks possible."""
         try:
-            transport.get_smart_client()
+            client = transport.get_smart_client()
         except (NotImplementedError, AttributeError,
                 errors.TransportNotPossible):
             # no smart server, so not a branch for this format type.
             raise errors.NotBranchError(path=transport.base)
         else:
+            # Send a 'hello' request in protocol version one, and fail if the
+            # server doesn't support our required version (2).
+            request = client.get_request()
+            smart_protocol = protocol.SmartClientRequestProtocolOne(request)
+            smart_protocol.call('hello')
+            server_version = smart_protocol.read_response_tuple(expect_body=False)
+            if server_version != '2':
+                raise errors.NotBranchError(path=transport.base)
             return klass()
 
     def initialize_on_transport(self, transport):

=== modified file bzrlib/remote.py
--- bzrlib/remote.py
+++ bzrlib/remote.py
@@ -53,7 +53,6 @@
             self._medium = None
             return
 
-        self._ensure_real()
         path = self._path_for_remote_call(self._client)
         response = self._client.call('BzrDir.open', path)
         if response not in [('yes',), ('no',)]:

=== modified directory  // last-changed:andrew.bennetts at canonical.com-200704241
... 02546-am5s92urrlfk9zjb
# revision id: andrew.bennetts at canonical.com-20070424102546-am5s92urrlfk9zjb
# sha1: 8ab7cddcafc10ecf135866e2a109acde95a2e014
# inventory sha1: 57525a6324a9cf2bcf078bfccfaa9b7971cd1946
# parent ids:
#   andrew.bennetts at canonical.com-20070424090150-9buzrpi8lt6qv0tg
# base id: andrew.bennetts at canonical.com-20070424090150-9buzrpi8lt6qv0tg
# properties:
#   bugs:
#   branch-nick: hpss-vfs-fallback