Fixes#966
* As a preallocation optimization, ``list()`` calls ``__len__`` on its
parameter if it's available
* Before Python 2.7.4, WeakSet has a bug[0] where ``len()`` is unsafe: it is
done by iteration and weakrefs may be removed from the underlying set during
the iteration
As a result, the safety feature of listifying a WeakSet to ensure we have
strong refs on all items during iteration may blow up.
Wrapping the weakset in a ``iter()`` makes ``__len__()`` invisible and ensures
we're within the IterationGuard[1].
Which now that I think about it means we *should* be able to safely iterate
weaksets in the first place and may not have needed to listify them...
[0] http://bugs.python.org/issue14159
[1] http://hg.python.org/cpython/file/b6acfbe2bdbe/Lib/_weakrefset.py#l58
Likely caused by a type incoherence e.g. providing an id as string when the
table uses integer ids. Postgres performs an implicit conversion from string
to integer[0], this wasn't much of an issue in the old API, whatever cache was
there would simply not be used, but because the new API's cache is part of its
behavior it has a semantic impact and can lead to infinite recursion.
[0] more precisely from quoted value, which is untyped
A squashed merge is required as the conversion of the apiculture branch from
bzr to git was not correctly done. The git history contains irrelevant blobs
and commits. This branch brings a lot of changes and fixes, too many to list
exhaustively.
- New orm api, objects are now used instead of ids
- Environements to encapsulates cr uid context while maintaining backward compatibility
- Field compute attribute is a new object oriented way to define function fields
- Shared browse record cache
- New onchange protocol
- Optional copy flag on fields
- Documentation update
- Dead code cleanup
- Lots of fixes
Xavier Morel
Raphael Collet