[patch] Absolute reference to logo for rss and notification

[osimons]

The current chrome.logo implementation is not really complete with regards to references to the logo, and for a normal use case (like the default) it is very cumbersome to use as it returns it as server-root absolute (like /myproject/chrome/site/mylogo.png) instead of fully absolute with scheme and servername, or strictly project-relative like most other resources. That means you can't just call abs_href.chrome() on the logo reference either when you need that for rss or html email.

Also, we return to the template a variable called chrome.logo.src_abs (as True or False) that is only used one place - in the timeline.rss template. Additionally, it does not work there and no logo is displayed for timeline feeds. Here is that faulty code and the use for src_abs that makes no sense as a boolean:

<url>${chrome.logo.src_abs and chrome.logo.src_abs or abs_href(chrome.logo.src)}</url>

I've made a patch for this behavior whereby we change the chrome.logo.src_abs to actually return a reference to the absolute location - as good as can be calculated at least. Current behavior for chrome.logo.src as a server relative path has not been changed, so this should not impact current uses of that (see tests for confirmation).

Summary:

• get_logo_data() takes both a href and optionally an abs_href and returns both the relative (src) and absolute path (src_abs) always - as correct as possible based on the data we have for each use case at least.
• Updated the various feed templates to use the absolute reference directly.
• Added some tests for this additional behaviour.

An open TODO is left for possibly using chrome.htdocs_location for logos in common htdocs, but with the option to set a full reference anyway this should not be a big deal. Further changes are needed to get that variable in and used. Is it needed, or just let it be?

Attaching the patch to this ticket for review / approval before committing - and leaving some docs for the future :-)

[osimons]

Initial patch for returning both a relative and absolute path to the logo.

[osimons]

Chatted with eblot, and we decided to bump the priority on this - it should be in 0.11 as it is among other things needed to make our RSS valid for most common logo setups. See #6556 for related discussion.

[osimons]

Fix based on patch applied in [6384].