Change window.location prototype to disable certain redirects?

Question

I'm trying to selectively disable window.location, using Greasemonkey, at the start of the document.

I don't want to fully disable javascript, just disable some redirects done with javascript. They look like this:

window.location = "unwanted url";

Answer 1

You can't change the window.location prototype, because this a "native property" of window and it is not configurable.

On Firefox (Greasemonkey), if you try to override this then you will get errors like:

TypeError: can't redefine non-configurable property 'location'

and

Error: Permission denied to shadow native property

...depending on how you attempt it. Other browsers give similar errors.

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To block this kind of relocation, you need to interfere with the page's javascript on a case-by-case basis.

See "Stop execution of Javascript function (client side) or tweak it" for a general approach that works in Firefox. Although it may be much easier, depending on your target page's exact code.