self._tbuf was unexpectedly None.  The only way this can happen is
when the storage is closed (probably by a different thread); close()
sets _tbuf to None.  It turns out that a TransactionBuffer instance
can safely be closed more than once, so there's no need to set _tbuf
to None in the close() method.

recent confusion would have been avoided had the instructions been
followed.

I am glad to make this commit that fixes up a lot of the FTP
implementation. I fixed the behavior of many of the FTP commands,
including LIST, SIZE, and CWD.

I moved the original VFSFile/DirectoryView into abstract classes and wrote
a special implementation for each content type, which makes the code much
more flexible.

Also I finally implemented a smart way of adding files via VFS through
file extension introspection, based on Jim's ExtensionViewName proposal.

I am adding documentation in the DevelCookbook right now and will later
add a README file.

TODOs:

- make VFS View names flexible, so that file extensions specify views.

- Simplify ZCML directives, so that one can add new extensions for Add views
  quicker. A solution might look like that:

      <vfs:view
          name=".dtml"
          for="Zope.App.OFS.Container.IAdding."
          factory=".DTMLPageAdd."
          permission="Zope.ManageContent">
        <vfs:extension name=".html" />
        <vfs:extension name=".xul" />
        <vfs:extension name=".xml" />
        ...
      </vfs:view>

  This method would also be good for defining a default fiel extension.

- Show an object with its default file extension.

bsddb3Storage becomes BDBStorage
Full becomes BDBFullStorage
Minimal becomes BDBMinimalStorage

Removing MinimalReplicated.py, Packless.py, and base.py

- start_zeo_server():  Only quote the command line args for Windows;
  these break the tests on Linux, which would only need the quoting if
  the shell were involved: it's not for os.spawnve().

Merge to HEAD: The ZEO unit tests and wo_pcgi.py didn't run on Windows if the path to the python executable included a space.

storage's artifacts.  Some tests expect to reconnect in read-only mode
to a previously created storage.

Starts near the end of the file and reads forward, looking for a
complete snapshot.  If it doesn't find one, move farther from the end
and repeat.

XXX This approach does N**2 reads, where N is the number of times we
need to move further back and retry.  When we move backwards, we
double the distance from the end of the file.

This processes the whole file from the beginning collecting info about
active / blocked transactions.  This version is preliminary because it
needs to start at the end and backup until it has enough information.

tpc_begin() doesn't return anything anyway.
Rename transaction to txn to make lines shorter.

Should the deadline by checked inside this final loop waiting for
wrappers to finish?

Get ZClasses working.  (Tested this time.)
Add some more comments and add XDECREFs to avoid leaks.
Remove redundant check of ExtensionClass in get_class().
Apparent fix for ZClass persistent_id problem.

doesn't put .loop() in the package namespace.  Use the full dotted
path to the function.

which doesn't put .loop() in the package namespace.  Use the full
dotted path to the function.

which doesn't put .loop() in the package namespace.  Use the full
dotted path to the function.

Also, fix a docstring typo.

ThreadedAsync which doesn't put .loop() in the package namespace.  Use
the full dotted path to the function.

FileIterator.__len__(): Add this for Python 2.1 support.

Windows doesn't have it until Python 2.3

admin address of the subprocess.  Better to gulp 'em now than sip 'em
later.

shutdown_zeo_server(): Same thing here, but notice that on Windows,
the recv() can raise an ECONNRESET, which I believe we can just
ignore.  (Will test this with Tim shortly.)

Instead use self.new_dest() to get a new destination storage.

XXX It would still be useful to check for cross-storage-implementation
restores.  IOW, fs->bdb, bdb->fs (others?).

the warnings until the other fixes are ported to ZODB4.

Added an XXX to memind me.

function.  This was a nasty decoy (am I using that term correctly?
:).

Because we're worried about backward compatibility, for now we'll
rebind asyncore.loop() to a function that prints a warning and then
calls loop().  Eventually we'll take this away so you have to call
ThreadedAsync.loop() explicitly.

through the sneakily rebound asyncore.loop().

rename UnixTests to FileStorageTests, and add a simple BDBTests class
to use Berkeley Full storage.

Rewrite to use the new forker module api.

WindowsTests: Removed.

rename UnixConnectionTests to FileStorageConnectionTests, and add a
simple BDBConnectionTests class to use Berkeley Full storage.

WindowsConnectionTests: Removed.