How to disable browser nuisance "window.onbeforeunload" event

It's never present when required and appears as real nuisance on other sites, when dialogue pops up "confirm navigation" "leave this page."

Is there any new Opera built in setting to control this behaviour?

Using 3rd party applications to disable this is not a solution.

Thanks. Somehow I searched but missed this simple selection.

But I totally disagree - perhaps only 50% downloaded file names can make any sense at the moment when downloading but already a week later there is a puzzle ... but rest names doesn't make any sense.

Luckily there still is "save as" to avoid this.
Thanks

Thanks for your comments.
After MSIE there are also Mozilla and Chrome.

Question is of most common action where Opera 30 has failed:

Download a file and "save as" with name which makes sense

After 10 years usage, I still like Opera browser but only half minded would use Opera download function as it is implemented now.

PS.
Actually my posting purpose was to get instructions how to change Opera settings to fix it.

I'll take a look at Blink later .... just now struggling with new Opera again.
When trying to copy to clipboard text from manufacturer's site which also is a link, Opera fails and opens the link.
MSIE11 is capable to provide both - when clicking to text opens link and when dragging over text it's selected and can be copied to clipboard.
It's not to blame Opera,just a real life example, how I must switch to MSIE to complete the task.

And even worse - earlier Opera right mouse click menu offered option "open with MSIE" is now missing and I have to copy address manually.

I have been using Opera near 10 years.
But latest incarnation are over my understanding.
Being able to save file under name which makes sense is essential.
Even MS accepts this, not speaking of Mozilla and Chrome, why not Opera?

Another cucumber is Opera favourites - I'm not able to save URL to any Bookmark/Favourites subfolder - usually new bookmark just lands in unsorted area. There is not any functional browse under hear icon, right of address bar.

It looks like new Opera interface is designed a la Windows 8, to be something it isn't for healthy mind.

After near 10 years with Opera I can still play around for a while hoping to understand what is going one but not forever.

Thanks for comments.

Actually Opera is very uncomfortable then. Downloading 10-15 driver files, 3-4 at a time, doesn't leave much time to trace what is what, as file numbers doesn't describe a content.

Max points here to MSIE11 and Opera zero points.

For power user there is no choice - using MSIE I can complete task in 1/3 time and without paper and pencil

PS. most sites use same download obfuscation ... not only HP.

When downloading computer drivers from HP site, there is no option to rename downloaded file.

1. When clicking to link download immediately starts
2. When clicking to link with right mouse button an choosing "Save as" a html save is suggested.

Using MSIE11 there is no problem to choose "save as" and rename file before downloading.

Opera 30.0.1835.125 and Windows 8.1

Any suggestion how to fix Opera instead using MSIE11?
Thanks

Hello

PC has been running since Dec 13, 2014 without restart. Opera has only one profile and any cache hasn't been cleared AFAIK.
Is there any actual file to check for history?
Thanks.

Opera 26 History last month content is missing. There is only 4 days of present month under History Last Month option.
Is there any other way how to view recover history of visited sites?
I need sites visited 2 weeks ago.

But that doesn't explain why Opera sessions loose LAN connection after running for 20 minutes.
This flaw has got worse today, sessions loose connectivity after 5 minutes and Opera in fact is not usable.

Therefore I have forced to MSIE now.