Ublock: $generichide filter entry appears twice in the Logger on first load

[rjkpa]

Describe the issue

$generichide filter entry appears TWICE in the Logger on first load.

One or more specific URLs where the issue occurs

https://www.cbr.com/

Screenshot in which the issue can be seen

Steps for anyone to reproduce the issue

1) Add @@||cbr.com^$generichide in _My Filters_.
2) Keeping the logger open, browse to https://www.cbr.com/ in a new tab.
3) Go back to the running logger and notice a double entry for generichide filter.

Expected result

To show a single entry for $generichide filter as usual.

Actual result

Shows an additional entry during the first load.

Your settings

• OS/version: Win 10 Pro x64
• Browser/version: Chromium 64
• uBlock Origin version: 1.14.17.102

Your filter lists

Default + CSP filter for cbr.com

[rjkpa]

Not specific to cbr.com though as it happens on any domain on first load - https://i.imgur.com/EeYHd6e.png

[gwarser]

Confirmed on Firefox Nightly.

[toshiya44]

Most likely a webext only issue. I don't get this on Waterfox with latest legacy version of uBO.

[rjkpa]

More likely a regression left out which wasn't patched yet.

[gorhill]

Not a regression, neither a webext-only issue, this has been there forever with Chromium. It's just how it's not trivial to associate a tab with a URL for that tab internally. This can be done through webRequest.onBeforeRequest API, or webNavigation.onCommitted API. There is no guaranteed order between these two events, and as a consequence uBO must internally associate the tab and the URL in it from within these two listeners. Doing so causes the duplicate log entry.