Formerly, underlying queue was implemented in terms of two lists.  The
new queue is a series of singly-linked fixed length lists.

The new implementation runs much faster, supports multi-way tees, and
allows tees of tees without additional memory costs.

The root ideas for this structure were contributed by Andrew Koenig
and Guido van Rossum.

the file is a symlink.  Instead, use os.lstat directly, if it exists;
fall back on os.stat or the built-in open.  Thanks to Iustin Pop.

(same as commit of Sun Nov 2 to the release23-maint branch)

(same as commit of Sun Nov 2 to the release23-maint branch)

(same as commit of Sun Nov 2 to the release23-maint branch)

added a specific \ref to 5.9 in lieu of previous vague "see above".
(same as commit of Sun Nov 2 to the release23-maint branch)

sf bug#812818.
(same as commit of Sun Nov 2 to the release23-maint branch)

(same as commit of Sun Nov 2 to the release23-maint branch)

is exhausted.

[ 819012 ] Fix for former/latter confusion in Extending documentation

although not by using supplied patch.

Backported to 2.3.

Also fix use of n for two different variables in two different blocks.

  memory leak that would've occurred for all iterators that were
  destroyed before having iterated until they raised StopIteration.

* Simplify some code.

* Add new test cases to check for the memleak and ensure that mixing
  iteration with modification of the values for existing keys works.

(Contributed by George Yoshida.)

(Contributed by George Yoshida.)

* Add support for multiple iterator/generator objects at once on the simple
  bsddb _DBWithCursor interface.

has been closed" exceptions.

Adds a DBCursorClosedError exception in the closed cursor case for
future use in fixing the legacy bsddb interface deadlock problems
due to its use of cursors with DB_INIT_LOCK | DB_THREAD support
enabled.