New bug and task page URL structure makes canonical_url ambiguous for bug-related objects

The new bug and task page URL structure that I'm working on will make sure that, when viewing a bug, one is *always* in a context. Generally, I believe this to be a good thing, because in Real World use cases, it seems difficult to imagine a practical use case for viewing a bug outside of any context, and having context info allows us to tweak the UI for increased usability.

But, this raises the question: what is the "canonical_url" of bug-related objects? E.g. From bug-attachment-add.pt, the link to edit an attachment looks like:

    (<a tal:attributes="href attachment/fmt:url">edit</a>)

But the canonical_url for an attachment currently returns a URL like:

    /malone/bugs/1/attachments/2

In the new structure, that URL would have to be something like:

    /products/firefox/+bugs/1/attachments/1

i.e. the URL will change depending on your context. For now, I've worked around this in a manner similar to how these links are created in other portlets:

    (<a tal:attributes="href string:${bugtask_url}/attachments/${attachment/id}">edit</a>)

but the question of "what is the canonical_url of a bug-related object?" still needs to be answered.