Merge lp:~jameinel/bzr/2.0.4-autopack-507566 into lp:bzr/2.0

[John A Meinel]

[John A Meinel (jameinel)]

This is a bugfix for the 'critical' bug #507566. It seems that if you had concurrent autopacking, the second one would restart, but 'forget' that it had a new pack which needed to be added.

This seems localized enough that it is worth fixing in the 2.0 series.

[Robert Collins (lifeless)]

 review: +1

review: Approve

=== modified file 'NEWS'
--- NEWS	2010-01-15 03:34:28 +0000
+++ NEWS	2010-01-16 20:52:12 +0000
@@ -38,6 +38,11 @@
   returns ``EINTR`` by calling ``PyErr_CheckSignals``.  This affected the
   optional ``_readdir_pyx`` extension.  (Andrew Bennetts, #495023)
 
+* Concurrent autopacks will no longer lose a newly created pack file.
+  There was a race condition, where if the reload happened at the right
+  time, the second packer would forget the name of the newly added pack
+  file. (John Arbash Meinel, Gareth White, #507566)
+
 * Give a clearer message if the lockdir disappears after being apparently
   successfully taken.  (Martin Pool, #498378)
 

=== modified file 'bzrlib/repofmt/pack_repo.py'
--- bzrlib/repofmt/pack_repo.py	2009-09-09 18:52:56 +0000
+++ bzrlib/repofmt/pack_repo.py	2010-01-16 20:52:12 +0000
@@ -1,4 +1,4 @@
-# Copyright (C) 2005, 2006, 2007, 2008 Canonical Ltd
+# Copyright (C) 2007-2010 Canonical Ltd
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -1987,8 +1987,13 @@
         if first_read:
             return True
         # out the new value.
-        disk_nodes, _, _ = self._diff_pack_names()
-        self._packs_at_load = disk_nodes
+        disk_nodes, deleted_nodes, new_nodes = self._diff_pack_names()
+        # _packs_at_load is meant to be the explicit list of names in
+        # 'pack-names' at then start. As such, it should not contain any
+        # pending names that haven't been written out yet.
+        pack_names_nodes = disk_nodes.difference(new_nodes)
+        pack_names_nodes.update(deleted_nodes)
+        self._packs_at_load = pack_names_nodes
         (removed, added,
          modified) = self._syncronize_pack_names_from_disk_nodes(disk_nodes)
         if removed or added or modified:

=== modified file 'bzrlib/tests/test_repository.py'
--- bzrlib/tests/test_repository.py	2009-09-09 01:58:47 +0000
+++ bzrlib/tests/test_repository.py	2010-01-16 20:52:12 +0000
@@ -1,4 +1,4 @@
-# Copyright (C) 2006, 2007, 2008, 2009 Canonical Ltd
+# Copyright (C) 2006-2010 Canonical Ltd
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -62,6 +62,7 @@
     revision as _mod_revision,
     symbol_versioning,
     upgrade,
+    versionedfile,
     workingtree,
     )
 from bzrlib.repofmt import (
@@ -1279,6 +1280,45 @@
         self.assertEqual({revs[-1]:(revs[-2],)}, r.get_parent_map([revs[-1]]))
         self.assertFalse(packs.reload_pack_names())
 
+    def test_reload_pack_names_preserves_pending(self):
+        # TODO: Update this to also test for pending-deleted names
+        tree, r, packs, revs = self.make_packs_and_alt_repo(write_lock=True)
+        # We will add one pack (via start_write_group + insert_record_stream),
+        # and remove another pack (via _remove_pack_from_memory)
+        orig_names = packs.names()
+        orig_at_load = packs._packs_at_load
+        to_remove_name = iter(orig_names).next()
+        r.start_write_group()
+        self.addCleanup(r.abort_write_group)
+        r.texts.insert_record_stream([versionedfile.FulltextContentFactory(
+            ('text', 'rev'), (), None, 'content\n')])
+        new_pack = packs._new_pack
+        self.assertTrue(new_pack.data_inserted())
+        new_pack.finish()
+        packs.allocate(new_pack)
+        packs._new_pack = None
+        removed_pack = packs.get_pack_by_name(to_remove_name)
+        packs._remove_pack_from_memory(removed_pack)
+        names = packs.names()
+        all_nodes, deleted_nodes, new_nodes = packs._diff_pack_names()
+        new_names = set([x[0][0] for x in new_nodes])
+        self.assertEqual(names, sorted([x[0][0] for x in all_nodes]))
+        self.assertEqual(set(names) - set(orig_names), new_names)
+        self.assertEqual(set([new_pack.name]), new_names)
+        self.assertEqual([to_remove_name],
+                         sorted([x[0][0] for x in deleted_nodes]))
+        packs.reload_pack_names()
+        reloaded_names = packs.names()
+        self.assertEqual(orig_at_load, packs._packs_at_load)
+        self.assertEqual(names, reloaded_names)
+        all_nodes, deleted_nodes, new_nodes = packs._diff_pack_names()
+        new_names = set([x[0][0] for x in new_nodes])
+        self.assertEqual(names, sorted([x[0][0] for x in all_nodes]))
+        self.assertEqual(set(names) - set(orig_names), new_names)
+        self.assertEqual(set([new_pack.name]), new_names)
+        self.assertEqual([to_remove_name],
+                         sorted([x[0][0] for x in deleted_nodes]))
+
     def test_autopack_reloads_and_stops(self):
         tree, r, packs, revs = self.make_packs_and_alt_repo(write_lock=True)
         # After we have determined what needs to be autopacked, trigger a