bzr: ERROR: exceptions.SystemError: Negative size passed to PyString_FromStringAndSize when dirstate file has additional \0 at the end of the file

[cbr]

if a dirstate file ends up with a spare \0 at the end of the file, the parser croaks. This may be happening because of the use of truncate()

I am running bzr via sftp over openvpn from a laptop to a server.
bzr return a seg-fault when I try to commit
See the following

flyvemaskine:~/src/work/dversion> bzr commit
Segmentation fault
flyvemaskine:~/src/work/dversion> bzr status
Segmentation fault

flyvemaskine:~/src/work/dversion> bzr check
checked branch file:///home/cbr/src/work/dversion/ format Bazaar Branch Format 6 (bzr 0.15)
checked repository <bzrlib.transport.local.LocalTransport url=file:///home/cbr/src/work/> format <RepositoryFormatKnitPack1>
bzr: ERROR: exceptions.SystemError: Negative size passed to PyString_FromStringAndSize

Traceback (most recent call last):
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 834, in ...
  File "_dirstate_helpers_c.pyx", line 661, in _dirstate_helpers_c.Reader._parse_dirblocks
  File "_dirstate_helpers_c.pyx", line 626, in _dirstate_helpers_c.Reader._get_entry
SystemError: Negative size passed to PyString_FromStringAndSize

bzr 1.3.1 on python 2.5.2.final.0 (linux2)
arguments: ['/usr/bin/bzr', 'check']

[edymtt (edymtt)]

I think I'm having the same problem. I have the following setup:

 * I use bzr 1.5 under Ubuntu 8.04;
 * Ubuntu is running under VirtualBox 1.6 with Windows XP Professional SP2 as host OS;
 * the branch is on a NTFS partition and is accessed by Ubuntu through a (permanent) shared folder made with VirtualBox.

I can use the branch without problems for a while, then suddenly bzr throws an exception. If I delete the .bzr directory and recreate the branch the branch works fine... until the next "corruption". Below the output - first I invoke status, next a check:

ermiotto@hardy-vbox:/mnt/shared/intelligenti/progetto_si$ bzr status
bzr: ERROR: exceptions.SystemError: Negative size passed to PyString_FromStringAndSize

Traceback (most recent call last):
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 846, in run_bzr_catch_errors
    return run_bzr(argv)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 797, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 499, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 807, in ignore_pipe
    result = func(*args, **kwargs)
  File "/usr/lib/python2.5/site-packages/bzrlib/builtins.py", line 178, in run
    show_pending=not no_pending)
  File "/usr/lib/python2.5/site-packages/bzrlib/status.py", line 117, in show_tree_status
    want_unversioned=want_unversioned)
  File "/usr/lib/python2.5/site-packages/bzrlib/tree.py", line 93, in changes_from
    want_unversioned=want_unversioned,
  File "/usr/lib/python2.5/site-packages/bzrlib/decorators.py", line 127, in read_locked
    return unbound(self, *args, **kwargs)
  File "/usr/lib/python2.5/site-packages/bzrlib/tree.py", line 734, in compare
    want_unversioned=want_unversioned)
  File "/usr/lib/python2.5/site-packages/bzrlib/delta.py", line 217, in _compare_trees
    want_unversioned=want_unversioned):
  File "/usr/lib/python2.5/site-packages/bzrlib/workingtree_4.py", line 1836, in iter_changes
    state._read_dirblocks_if_needed()
  File "/usr/lib/python2.5/site-packages/bzrlib/dirstate.py", line 1963, in _read_dirblocks_if_needed
    _read_dirblocks(self)
  File "_dirstate_helpers_c.pyx", line 694, in _dirstate_helpers_c._read_dirblocks_c
  File "_dirstate_helpers_c.pyx", line 661, in _dirstate_helpers_c.Reader._parse_dirblocks
  File "_dirstate_helpers_c.pyx", line 583, in _dirstate_helpers_c.Reader._get_entry
  File "_dirstate_helpers_c.pyx", line 502, in _dirstate_helpers_c.Reader.get_next_str
SystemError: Negative size passed to PyString_FromStringAndSize

bzr 1.5 on python 2.5.2 (linux2)
arguments: ['/usr/bin/bzr', 'status']
encoding: 'UTF-8', fsenc: 'UTF-8', lang: 'en_US.UTF-8'
plugins:
  bzrtools /usr/lib/python2.5/site-packages/bzrlib/plugins/bzrtools [1.5.0]
  launchpad /usr/lib/python2.5/site-packages/bzrlib/plugins/launchpad [unknown]
*** 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.
ermiotto@hardy-vbox:/mn...

[James Westby (james-w)]

Hi,

Would someone be able to provide a copy of the .bzr/checkout/dirstate
from a branch that exhibits this behaviour?

Thanks,

James

[edymtt (edymtt)]

Hi,

I've attached the .bzr/checkout/dirstate from a corrupted branch.

  Eric

[James Westby (james-w)]

On Tue, 2008-06-17 at 17:31 +0000, edymtt wrote:
> Hi,
>
> I've attached the .bzr/checkout/dirstate from a corrupted branch.

Thanks.

The code in question is

    cdef char *get_next(self, int *size):
        """Return a pointer to the start of the next field."""
        cdef char *next
        next = self.cur_cstr
        self.cur_cstr = <char*>memchr(next, c'\0', self.end_cstr-next)
        size[0] = self.cur_cstr - next
        self.cur_cstr = self.cur_cstr + 1
        return next

    cdef object get_next_str(self):
        """Get the next field as a Python string."""
        cdef int size
        cdef char *next
        next = self.get_next(&size)
        return PyString_FromStringAndSize(next, size)

with the last line causing the error.

If memchr fails to find the null then it will return NULL, and you
will end up with a negative number.

You file seems to have an extra null byte at the end, which may well
be cause of the problem.

Thanks,

James

[edymtt (edymtt)]

Hi,

I've found the time to delete the extra null byte at the end of my .bzr/checkout/dirstate. bzr status gave me no error.

Since I had modified files in that branch, I did a commit. It went well, but next bzr status gave me the error we are discussing in this bug. I deleted the null byte again and I had no problem with bzr status and bzr check.

Thanks for the tip, James!

  Eric

[Robert Collins (lifeless)]

I would change 'space' to 'spare' but I'm getting the red border (bad json) error and after 10 edit attempts am moving on.

[Launchpad Janitor (janitor)]

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