Hi, we have a private wiki and recently installed 1.22. When editing a page with an inputbox wiki text, after using WikiEditor "Preview" tab, "Show Preview" works as the save button and saves contents to the main page. If only "Show Preview" is used, everything is fine.
Example wiki text: <inputbox>type=create</inputbox>
If someone can try the same scenario (Edit a random page -> put "<inputbox>type=create</inputbox>" there -> click "Preview" -> click "Show Preview") on their freshly installed 1.22 MediaWiki and let me know how it worked, that would be great.
I can confirm this same bug across more MW versions than 1.22, effects 1.19 and 1.21 with different skins(Vector and a Custom skin). I can also reproduce, just use side-by-side preview, click save and your 'Main page' is rewritten. Very dangerous because it rewrites your main page without warning. All links on page to point back at current page are rewritten to 'Main page'. I'll file a bug report for InputBox.
Thank you Hutchy. Here is a link to the bug for tracking purposes. Also a similar bug was filed and fixed recently.
I think I've found something that might help (tested on our 1.24.1 instance).
It appears to be related to the WikiEditor extension, specifically, the preview/changes tabs that come with it. The solution that's worked for me is to disable these tabs in LocalSettings.php using
$wgDefaultUserOptions['wikieditor-preview'] = 0;
HTH