> Just copy Chrome and confine all modal dialog boxes such as HTTP basic auth and Javascript alert() to the individual browser tab. No individual tab should every be allowed to pop a modal that prevents interaction with any other tab, any other browser window.
So, `alert()` was fixed about 10 years ago in Firefox.
I'm not sure why the "Authentication Required" dialog wasn't, but I'm willing to bet it's something that was blocked indirectly by the old extension infrastructure (the so-called XUL extensions): until Firefox ~57, huge chunks of the architecture of Firefox were impossible to touch without breaking XUL extensions at a fundamental level, and this included making many things non-blocking.
If I'm right, it's the kind of thing that can now be fixed.
The answer is probably something like "that dialog came from necko, because we didn't put in a good way to propagate blocking prompts back up from the network layer in a way that identifies which tab wants the request".
If extensions were the problem an interface to actually let the extensions work would have been created. As it is you still can't implement a password manager natively.
So, `alert()` was fixed about 10 years ago in Firefox.
I'm not sure why the "Authentication Required" dialog wasn't, but I'm willing to bet it's something that was blocked indirectly by the old extension infrastructure (the so-called XUL extensions): until Firefox ~57, huge chunks of the architecture of Firefox were impossible to touch without breaking XUL extensions at a fundamental level, and this included making many things non-blocking.
If I'm right, it's the kind of thing that can now be fixed.