EN.WP.ST47 wrote:

Bugzilla is not a help forum. Try the village pumps, especially WP:VP/T on en.wiki, you'll get much more attention for your question there. If they do determine that it's an issue with MediaWiki, let us know.

Basically what is happening:

Your function addButton's name conflicts with the builtin addButton (aka mw.toolbar.addButton ) (from mediawiki.action.edit module).

So what happens is:
$(addButton) -> addButton( $ ) -> mw.toolbar.addButon( $) -> mw.toolbar.insertButon( $ )

Which in turns inserts a toolbar button, where the url for the image to use is the $ function (since that's what first arg of insertButton is), and $.toString() is the url you see loaded.

Hmm.. I though ResourceLoader was wrapping user scripts into a function, but it seems I was wrong, per bug 32537 comment 5.

Thanks for clarifying this.

All resource loader modules loaded via mw.loader are executed from a closure, that is correct.

However the 'site' (common.js & <skinname>.js) module and 'user' module (common.js & <skinname>.js) are not loaded via mw.loader.load. This was done to allow shared caching of the default load batch queue. But the site and user module aren't just loaded outside the default queue, they aren't loaded via mw.loader.load at all.

They are loaded with a separate <script> tag directly to load.php?module=user&only=scripts
This allows 2 things:

• separating styles into a different load (namely a <link rel=stylesheet> on top of the page, before the content to avoid a Flash Of Unstyled Content (FOUC))
• executing JS in the global scope for backwards compatibility (many gadgets ask users to put 'var foobar = 123;' in the user script to set certain variables. Those would have to be updated to 'window.foobar = 123;' to do the same.