Typing into text field when in media search dialog, using Opera 36 (Blink rendering engine, like Chrome/Chromium), hangs the browser tab and continues consuming 100% of one CPU core and more and more memory until the browser tab crashes. I can reproduce this reliably.
In this video, I am editing http://en.wikipedia.beta.wmflabs.org/wiki/Non-existent_page (it happens on existing pages too, I just happened to record this one) and experiencing the issue. I'm trying to type "example", the page becomes unresponsive after "exampl". It seems to happen if I pause typing for a while.
It takes a couple of minutes for the page to actually crash, with memory use of the tab rising continuously to around 1.5 GB, the eventual result is:
(It also showcases two other issues – the "Notices" popup remains partially visible when it should be closed, which I guess is a rendering bug, and the page URL changes to ?action=edit when it should be ?veaction=edit, which is probably a VE bug.)
Using Opera 36 beta on Windows 7: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.23 Safari/537.36 OPR/36.0.2130.2 (Edition beta). It also happened before a browser update: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.82 Safari/537.36 OPR/35.0.2066.35 (Edition beta).