itbox.ua causes palemoon to hang with 100% CPU usage

[Harkonnen]

If you press "buy" button on itbox.ua (Ukrainian internet shop), palemoon hangs with 100% CPU usage
Tested is safe mode on clean profile

Steps to reproduce
Open page for any item, f.e https://www.itbox.ua/product/Plenka_zaschitnaya_Grand-X_Anti_Glare_dlya_Nexus_7_II_PZGAGN7II-p187995/?utm_source=Hotline&utm_medium=PriceList_cpc&utm_campaign=zaschitnye_plenki&utm_content=U0125301&utm_term=Grand-X_Anti_Glare_dlya_Nexus_7_II
click Buy button (big orange one with "Купить")

[Moonchild]

If you give it time to have the hang monitor trigger, you'll get:

A script on this page may be busy, or it may have stopped responding. You can stop the script now, open the script in the debugger, or let the script continue.
Script: https://static.itbox.ua/build/main.js?20170329_3:36

Unfortunately it's a minified blurb, but the cause is a runaway script.
Since they use promises, it'll have JS waiting for something that's not handled.

Perhaps the webmasters can do something with the info below:

Code: Select all

15:05:12.719 "Unhandled promise rejection" Error: Syntax error, unrecognized expression: .product-nav__link[href="#p-similar"
Stack trace:
main</</xe</t.error@https://static.itbox.ua/build/main.js?20170329_3:3:13816
main</</xe</t.tokenize@https://static.itbox.ua/build/main.js?20170329_3:3:19777
main</</xe</t.select@https://static.itbox.ua/build/main.js?20170329_3:3:20044
t@https://static.itbox.ua/build/main.js?20170329_3:3:2805
main</</<.find@https://static.itbox.ua/build/main.js?20170329_3:3:22348
main</</ge.fn.init@https://static.itbox.ua/build/main.js?20170329_3:3:22844
main</</ge@https://static.itbox.ua/build/main.js?20170329_3:2:30465
t/<@https://static.itbox.ua/build/main.js?20170329_3:28:9447
i@https://static.itbox.ua/build/main.js?20170329_3:22:26053
c/<@https://static.itbox.ua/build/main.js?20170329_3:22:27464
u/</e[t]@https://static.itbox.ua/build/main.js?20170329_3:22:26229
r@https://static.itbox.ua/build/main.js?20170329_3:5:15450
r/<@https://static.itbox.ua/build/main.js?20170329_3:5:15556
main</Y/</s@https://static.itbox.ua/build/main.js?20170329_3:36:24410
main</Y/<@https://static.itbox.ua/build/main.js?20170329_3:36:24532
main</e.exports/l@https://static.itbox.ua/build/main.js?20170329_3:36:19316
1 main.js:36:24762
main</P/</t<() main.js:36
main</D() main.js:36
main</P/<() main.js:36
main</e.exports() main.js:10
<anonymous> main.js:13
main</g() main.js:13
main</y() main.js:13