1644800 - GeckoView navigation shouldn’t break if the beforeunload prompt is not implemented

Status: REOPENED

(GeckoView :: General, defect, P3)

Description

[Imanol Fernandez]

Attachment: logcat.txt

In FxR we found a freeze in GV navigation after exiting WebXR. It can be reproduced with navigating to https://doc.babylonjs.com/how_to/webxr_demos_and_examples and entering and exiting WebXR (note that it works perfectly downloading the code and running it outside their playground).

I have checked the usual problematic processes (compositor, parent process, UI thread, GV thread) and they look ok. WebGL still runs after exiting the demo and I can even click on the CSS to show the playground code or enter VR again.

The problem is that when trying to navigate GV to other page it doesn't do anything
I have checked the JS module logs and GeckoViewNavigation.jsm loadURI function is correctly called but it doesn't process it. WebBrowserChromeChild shouldLoadURI is not shown in the log after the navigation freeze. WebBrowserChromeChild shouldLoadURI was correctly printed when navigation worked before exiting WebXR

Logcat attached

Comment 1

[Emily Toop (:fluffyemily)]

This is a release blocker for FxR

Comment 2

[Imanol Fernandez]

it turns out the page is displaying a beforeunload prompt and we had not that implemented in FxR...

Comment 3

[Imanol Fernandez]

Reopening because this is still a bug: Navigation shouldn’t break because a prompt isn’t implemented.

Comment 4

[James Willcox (:snorp) ([e-mail]) (he/him)]

The default impl for onBeforeUnload() in PromptDelegate returns null, which the docs say deny the navigation. That's clearly the wrong thing to do here, we should instead allow the navigation in that case.