[DM] Fix traversal via unicode steps

[Andreas Jung]

2. Introduction

With Zope 2.10, PageTemplates use internally unicode. A so called (misnamed) unicode conflict resolver is responsible to convert values returned by TALES expressions to unicode. This means that the TALES path expression feature /.../?var/... has a good chance to get a unicode value for var -- and then fails miserably as the traversal logic does not expect unicode traversal steps.

3. Feature

Let OFS.Traversable.Traversable handle unicode steps correctly.

It might be possible that Zope 3 traversal needs a similar extension.

ATTENTION: If the traversal step contains non ascii characters (usually not the case), then Python's default encoding must be able to encode the step.

4. Example Use Cases

Necessary to let .../?var/... work reliable in PageTemplates.

[Colin Watson (cjwatson)]

The zope2 project on Launchpad has been archived at the request of the Zope developers (see https://answers.launchpad.net/launchpad/+question/683589 and https://answers.launchpad.net/launchpad/+question/685285). If this bug is still relevant, please refile it at https://github.com/zopefoundation/zope2.