bzr diff crashes with "unsupported operand type" with working tree format 4

[Martin Pitt]

After upgrading my postgresql bzr trees to the latest working tree format I noticed that bzr diff died with an exception when I renamed the top level directory.

Simple reproducer:

$ mkdir /tmp/x
$ cd /tmp/x
$ mkdir foo
$ echo hi> foo/hello.txt
$ bzr add .
$ bzr commit -m 'initial release'
added foo
added foo/hello.txt
Committed revision 1.
$ bzr mv foo bar
foo => bar
$ echo workd > bar/hello.txt
$ bzr diff
bzr: ERROR: exceptions.TypeError: unsupported operand type(s) for +: 'NoneType' and 'int'

Traceback (most recent call last):
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 650, in run_bzr_catch_errors
    return run_bzr(argv)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 612, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 304, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 622, in ignore_pipe
    result = func(*args, **kwargs)
  File "/usr/lib/python2.5/site-packages/bzrlib/builtins.py", line 1438, in run
    old_label=old_label, new_label=new_label)
  File "/usr/lib/python2.5/site-packages/bzrlib/diff.py", line 375, in diff_cmd_helper
    extra_trees=extra_trees)
  File "/usr/lib/python2.5/site-packages/bzrlib/diff.py", line 403, in show_diff_trees
    extra_trees=extra_trees)
  File "/usr/lib/python2.5/site-packages/bzrlib/diff.py", line 475, in _show_diff_trees
    _patch_header_date(old_tree, file_id, path))
  File "/usr/lib/python2.5/site-packages/bzrlib/diff.py", line 488, in _patch_header_date
    return timestamp.format_patch_date(tree.get_file_mtime(file_id, path))
  File "/usr/lib/python2.5/site-packages/bzrlib/timestamp.py", line 131, in format_patch_date
    tm = time.gmtime(secs+offset)
TypeError: unsupported operand type(s) for +: 'NoneType' and 'int'

bzr 0.15.0 on python 2.5.1.candidate.1 (linux2)
arguments: ['/usr/bin/bzr', 'diff']

If I use .bzr.backup with working tree format 3 this works as expected.

[Alexander Belchenko (bialix)]

This is duplicate of #103870. This bug already fixed and bugfix available in bzr.dev and in next release.