Bug: commit messes up working tree

[Stefan Ring]

I found a bug that leaves the tree in a messy unrecoverable state. When 
I was bitten today on a much larger tree, bzr would throw an exception 
on each subsequent "status" or "revert" (pretty much anything that 
requires a working tree, I guess). Unfortunately, I cannot reproduce 
this exception exactly but I have a very small testcase that shows the 
original failure.

Fortunately, the repo is not damaged by this -- bzr log shows the commit 
but bzr status shows a dirty state and bzr revert doesn't do anything.

Maybe I could reproduce the exception from earlier today if it would 
help. I still have the commit -- id is 
sring at gmx.net-20080213181510-t65qql3e7ph5g2bi, as a reminder to myself.

The two files in the test below are not empty (I don't know if that 
matters). Doing a bzr rm instead of a system rm helps.


Bazaar (bzr) 1.1.0
   Python interpreter: /opt/local/bin/python2.5 2.5.1.final.0

macbook:~/,checkout/bzr5 sr$ bzr log -v
------------------------------------------------------------
revno: 1
committer: Stefan Ring <s.r at visotech.at>
branch nick: bzr3
timestamp: Thu 2008-02-14 01:34:17 +0100
message:
   test case
added:
   a/
   a/c/
   a/c/x.txt
   a/c/y.txt
   b/
macbook:~/,checkout/bzr5 sr$ rm a/c/y.txt && bzr mv a/c b && rmdir a
a/c => b/c
macbook:~/,checkout/bzr5 sr$ bzr commit -m nasty
Committing to: /Users/sr/,checkout/bzr5/
missing a
renamed a/c => b/c
missing b/c/y.txt
deleted a
deleted a/c/y.txt
bzr: ERROR: dirstate: inconsistent delta, with tree 0. 'a/c/y.txt' 
'y.txt-20080214003415-9vmtr0dp2lydsug1-5'

Digging through the log file, this is the exception that happened 
immediately afterwards (on a different machine, bzr 1.1 fedora 8):

bzr arguments: [u'st']
looking for plugins in /home/sr/.bazaar/plugins
looking for plugins in /usr/lib/python2.5/site-packages/bzrlib/plugins
Plugin name __init__ already loaded
Plugin name __init__ already loaded
encoding stdout as sys.stdout encoding 'ANSI_X3.4-1968'
opening working tree '/huge/daily'
check paths: None
Traceback (most recent call last):
   File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 806, 
in run_bzr_catch_errors
     return run_bzr(argv)
   File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 762, 
in run_bzr
     ret = run(*run_argv)
   File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 492, 
in run_argv_aliases
     return self.run(**all_cmd_args)
   File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 772, 
in ignore_pipe
     result = func(*args, **kwargs)
   File "/usr/lib/python2.5/site-packages/bzrlib/builtins.py", line 189, 
in run
     to_file=self.outf, short=short, versioned=versioned)
   File "/usr/lib/python2.5/site-packages/bzrlib/status.py", line 114, 
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 707, 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 
2360, in _iter_changes
     result = _process_entry(current_entry, current_path_info)
   File "/usr/lib/python2.5/site-packages/bzrlib/workingtree_4.py", line 
1954, in _process_entry
     source_details = old_entry[1][source_index]
TypeError: 'NoneType' object is unsubscriptable

return code 4