Merge lp:~spiv/bzr/new-repo-stacking-bug-597942 into lp:bzr

[Andrew Bennetts]

Fix BzrDir.sprout to respect default stacking policies (#597942)

This fixes BzrDir.sprout to be aware that new repositories can have fallbacks even if the caller didn't ask for stacked=True. This happens when there is a default stacking policy at the target location.

An example that benefits is "bzr branch lp:bzr lp:~user/bzr/blah" will no longer transfer the full revision history.

[Andrew Bennetts (spiv)]

Btw, this fix is probably a good backport candidate for 2.0 and 2.1. I'll make separate proposals for those when this is landed.

[Robert Collins (lifeless)]

I'm amazed and shocked. Shocked I tell you.

Please be landing.

[Robert Collins (lifeless)]

review: Approve

[Andrew Bennetts (spiv)]

sent to pqm by email

=== modified file 'NEWS'
--- NEWS	2010-06-23 08:14:21 +0000
+++ NEWS	2010-06-24 06:42:28 +0000
@@ -43,6 +43,10 @@
 Bug Fixes
 *********
 
+* ``bzr branch`` to a new repository with a default stacking policy no
+  longer transfers the full history unnecessarily.
+  (Andrew Bennetts, #597942)
+
 * ``bzr init`` does not recursively scan directory contents anymore
   leading to faster init for directories with existing content.
   (Martin [gz], Parth Malwankar, #501307)

=== modified file 'bzrlib/bzrdir.py'
--- bzrlib/bzrdir.py	2010-05-25 17:27:52 +0000
+++ bzrlib/bzrdir.py	2010-06-24 06:42:28 +0000
@@ -1244,7 +1244,8 @@
         repository_policy = result.determine_repository_policy(
             force_new_repo, stacked_branch_url, require_stacking=stacked)
         result_repo, is_new_repo = repository_policy.acquire_repository()
-        if is_new_repo and revision_id is not None and not stacked:
+        is_stacked = stacked or (len(result_repo._fallback_repositories) != 0)
+        if is_new_repo and revision_id is not None and not is_stacked:
             fetch_spec = graph.PendingAncestryResult(
                 [revision_id], source_repository)
         else:

=== modified file 'bzrlib/tests/per_bzrdir/test_bzrdir.py'
--- bzrlib/tests/per_bzrdir/test_bzrdir.py	2010-05-20 18:23:17 +0000
+++ bzrlib/tests/per_bzrdir/test_bzrdir.py	2010-06-24 06:42:28 +0000
@@ -1168,6 +1168,29 @@
         self.assertEqual(tree.branch.last_revision(),
                          target.open_branch().last_revision())
 
+    def test_sprout_with_revision_id_uses_default_stack_on(self):
+        # Make a branch with three commits to stack on.
+        builder = self.make_branch_builder('stack-on')
+        builder.start_series()
+        builder.build_commit(message='Rev 1.', rev_id='rev-1')
+        builder.build_commit(message='Rev 2.', rev_id='rev-2')
+        builder.build_commit(message='Rev 3.', rev_id='rev-3')
+        builder.finish_series()
+        stack_on = builder.get_branch()
+        # Make a bzrdir with a default stacking policy to stack on that branch.
+        config = self.make_bzrdir('policy-dir').get_config()
+        try:
+            config.set_default_stack_on(self.get_url('stack-on'))
+        except errors.BzrError:
+            raise TestNotApplicable('Only relevant for stackable formats.')
+        # Sprout the stacked-on branch into the bzrdir.
+        sprouted = stack_on.bzrdir.sprout(
+            self.get_url('policy-dir/sprouted'), revision_id='rev-3')
+        # Not all revisions are copied into the sprouted repository.
+        repo = sprouted.open_repository()
+        self.addCleanup(repo.lock_read().unlock)
+        self.assertEqual(None, repo.get_parent_map(['rev-1']).get('rev-1'))
+
     def test_format_initialize_find_open(self):
         # loopback test to check the current format initializes to itself.
         if not self.bzrdir_format.is_supported():