Tested with IE 8 and latest RC of FF.
Current behaviour:
When clicking the "preview" or "show diff" button, the page reloads.
Evidence:
...after the DOM is ready...
...executed in JavaScript console...
mw.loader.getState('mediawiki.action.edit.preview');
'registered'
Expected behaviour:
When clicking the "preview" or "show diff" button, live preview just replaces some elements in the DOM. No page reload.
mw.loader.getState('mediawiki.action.edit.preview');
'ready'
How to reproduce:
Set your interface language to de or en, enable "Use live preview" in [[Special:Preferences]], go to a page, edit a section, click preview.
Note:
Using manually
mw.loader.load('mediawiki.action.edit.preview');
works perfectly: After it is loaded, LivePreview works as expected.
Version: 1.20.x
Severity: normal