[Firefox] chrome and about url wrongly identified

[quilloss]

uMatrix 0.9.1.3-dev.2
Firefox 40.0b1

Several chrome and about url are identified by uMatrix as blank.about-scheme.
For example about:addons and chrome://ublock0/content/dashboard.html.
It might apply for all urls of those schemes.
uMatrix 0.9.1.2 works fine.

[0xBRM]

All about:* URLs are a part of blank.about-scheme. As for uBlock's dashboard, it's a background page, so it makes sense. If you want to look at the b-t-s requests, you're going to have to open it in its own dashboard.

Edit: was trying to replicate it (successfully, which is the expected behaviour) and found an actual bug.

Steps to reproduce:

1. Go to ANY page https://github.com/
2. Go to about:about
3. Check the matrix

What happens: uMatrix is still stuck on github's page
Expected behaviour: blank.about-scheme

Works for some other about: pages as well, like about:cache.

[quilloss]

I would expect about:addons to result in addons.about-scheme and chrome://ublock0/content/dashboard.html to result in ublock0.chrome-scheme.
At least if I go by uMatrix 0.9.1.2 behavior.

Also https://github.com/gorhill/uMatrix/blob/master/src/js/tab.js#L72-L78

    var fakeHostname = scheme + '-scheme';

    if ( uri.hostname !== '' ) {
        fakeHostname = uri.hostname + '.' + fakeHostname;
    } else if ( scheme === 'about' ) {
        fakeHostname = uri.path + '.' + fakeHostname;
    }

[gorhill]

I would expect about:addons to result in addons.about-scheme and chrome://ublock0/content/dashboard.html to result in ublock0.chrome-scheme.

Yes, it's supposed to be like this for about:[...] pages, but for chrome://ublock0/[...] pages it links to the behind-the-scene scope because it used to be the only way to do it. This could be removed now that the behind-the-scene scope is available in the logger.

Regarding that about:[...] scheme, it seems it's again #262, which for whatever incredibly annoying reason, I just can't reproduce on my side.

[quilloss]

Could the issue be due to the changes for tabWatcher in d6a48df.

uMatrix 0.9.1.2
When navigating from about:blank to https://github.com/gorhill/uMatrix, 2 calls to TabContext.update is made. The call stack shows that the first came from httpObserver.observe and the second from tabWatcher.onLocationChange.

When navigating from about:blank to about:memory only the call originating from tabWatcher.onLocationChange is present.

uMatrix 0.9.1.3-dev.3
tabWatcher.onLocationChange is no longer there.
Navigating from about:blank to about:memory results in no call to TabContext.update.
Basically any navigation to an about:[...] will result in no call to TabContext.update.

[gorhill]

@quilloss Thanks for the investigation, this put me on the right track.

The real issue is not found in d6a48df, but rather in 4ab8f52: I should not have removed @AlexVallat's content-side code to deal with location changes. Even though this seems like this worked, I just found easy case to reproduce issues where the current way of dealing with URL change in the address bar does not work in uMatrix, even if I were to put back the code removed in d6a48df. The test is very simple:

• Type directly about:memory in the address bar, hit return.
• uMatrix is not aware of the location change.
• Type directly news.ycombinator.com in the address bar.
• uMatrix is aware of the location change.
• Type directly about:memory in the address bar.
• uMatrix is not aware of the location change.

So the real fix is to bring back the code removed in 4ab8f52. I did not realize back then that it was just not possible to reliably track location change without this code.