"bzr branch -r nnn" fails because of ghost revision

On Mon, 2008-07-14 at 22:04 +0000, Tom Cato Amundsen wrote:
> Public bug reported:
>
> Yet another ghost revision bug.
> The repository checked was on my local disk, but it is mirrored as http://www.solfege.org/bzr/solfege.dev
>

And quoth the source:

  # Note: The following line may raise KeyError in the event of
  # truncated history. We decided not to have a try:except:raise
  # RevisionNotPresent here until we see a use for it, because of the
  # cost in an inner loop that is by its very nature O(history).
  # Robert Collins 20080326
  parents = graph.get_parent_map([next_id])[next_id]

Thanks,

James

The patch below seems to work. But I don't understand bzr internals, so I cannot say if this is correct. I compared the output of "bzr selftest" before and after applying this, and it does not break any new tests.

=== modified file 'bzrlib/repository.py'
--- bzrlib/repository.py 2008-07-14 16:16:48 +0000
+++ bzrlib/repository.py 2008-07-15 21:25:40 +0000
@@ -1592,7 +1592,10 @@
             # RevisionNotPresent here until we see a use for it, because of the
             # cost in an inner loop that is by its very nature O(history).
             # Robert Collins 20080326
- parents = graph.get_parent_map([next_id])[next_id]
+ try:
+ parents = graph.get_parent_map([next_id])[next_id]
+ except KeyError:
+ raise errors.RevisionNotPresent(next_id, self)
             if len(parents) == 0:
                 return
             else:

With bzr 3.8 or 3.10.0, the ghost revisions bites me when I want to branch. It does not matter if I specify the revision by tag or revision number. But a checkout works ok.

tom@tomsin-laptop:~/src$ bzr branch -r tag:solfege-3.12.0 ~/src/solfege.repo/solfege.dev/ solfege-3.12
bzr: ERROR: exceptions.KeyError: 'Arch-1:<email address hidden>%solfege--unstable--3.1--version-0'

Traceback (most recent call last):
  File "/home/tom/lib/python/bzrlib/commands.py", line 893, in run_bzr_catch_errors
    return run_bzr(argv)
  File "/home/tom/lib/python/bzrlib/commands.py", line 839, in run_bzr
    ret = run(*run_argv)
  File "/home/tom/lib/python/bzrlib/commands.py", line 539, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/home/tom/lib/python/bzrlib/builtins.py", line 981, in run
    source_branch=br_from)
  File "/home/tom/lib/python/bzrlib/bzrdir.py", line 1133, in sprout
    source_branch.copy_content_into(result_branch, revision_id)
  File "/home/tom/lib/python/bzrlib/decorators.py", line 138, in read_locked
    result = unbound(self, *args, **kwargs)
  File "/home/tom/lib/python/bzrlib/branch.py", line 745, in copy_content_into
    self._synchronize_history(destination, revision_id)
  File "/home/tom/lib/python/bzrlib/branch.py", line 2141, in _synchronize_history
    Branch._synchronize_history(self, destination, revision_id)
  File "/home/tom/lib/python/bzrlib/branch.py", line 735, in _synchronize_history
    revision_id)))
  File "/home/tom/lib/python/bzrlib/repository.py", line 1652, in iter_reverse_revision_history
    parents = graph.get_parent_map([next_id])[next_id]
KeyError: 'Arch-1:<email address hidden>%solfege--unstable--3.1--version-0'

bzr 1.10 on python 2.5.2 (linux2)
arguments: ['/home/tom/bin/bzr', 'branch', '-r', 'tag:solfege-3.12.0', '/home/tom/src/solfege.repo/solfege.dev/', 'solfege-3.12']
encoding: 'UTF-8', fsenc: 'UTF-8', lang: 'nb_NO.UTF-8'
plugins:
  bzrtools /home/tom/.bazaar/plugins/bzrtools [1.10]
  cia /home/tom/.bazaar/plugins/cia [1.0dev]
  launchpad /home/tom/lib/python/bzrlib/plugins/launchpad [unknown]
  upload /home/tom/.bazaar/plugins/upload [0.1]
*** Bazaar has encountered an internal error.
    Please report a bug at https://bugs.launchpad.net/bzr/+filebug
    including this traceback, and a description of what you
    were doing when the error occurred.

The try-except-block in comment #2 above is not enough to make "bzr branch -r 898" work:
bzr: ERROR: Revision {Arch-1:<email address hidden>%solfege--unstable--3.1--version-0} not present in "KnitPackRepository('file:///home/tom/src/solfege.repo/.bzr/repository/')"

My branch fixes the original issue and "bzr check" with a ghost in the mainline. It does not yet fix "bzr reconcile".

patch submitted to the list