uBO doesn't apply :style() filters in some situations.

[kasper93]

Describe the issue

Now that I was forcefully converted to webext, let's report some bugs. I've found STR where style is not applied by :style() filter.

One or more specific URLs where the issue occurs

https://www.wykop.pl/wpis/25495975/ublock-lt-3/

Screenshot in which the issue can be seen

Actual

Expected

Steps to reproduce

1. Open the URL provided. Everything should look ok.
2. Open the same page in new tab. Middle mouse button on anything that point to the same page. I suggest timestamp (element after my nick) in post header.
3. Now switch to the new tab. You will see two things
   ** Cookie warning is hidden with the delay. It is hidden at the moment I switch to the new tab, so it is visible for a second. This is caused probably because user styles are injected in content scripts,
   ** But the main issues is that :style() is not applied at all leaving blank space there.

Reproduced everytime.

Both issues are not present on Chrome.

Your settings

• Browser/version: Firefox Nighty (20170720030203)
• uBlock Origin version: 1.13.9.0

Your filter lists

You need POL enabled to have affected filters.

The filters in question

wykop.pl##.cookie
wykop.pl##.type-permanent+#nav:style(top: 0px !important)
wykop.pl##.type-permanent+#nav+div:style(padding-top: 49px !important)

[gwarser]

Works for me. not any more :/
Nightly 2017-07-21 on linux

[gorhill]

I am assuming this is caused by the fact that the webext version is not using user styles, as opposed to the legacy version.

[gorhill]

After investigation, the issue is not really what I was expecting, I had assumed it was just a case of author css overriding uBO's css. This is not the case -- though probably implementing proper user styles will still fix the issue here.

The problem is that when uBO tries to inject its CSS, the head element of the document has not yet been parsed, and uBO expects this element to be present when injecting its style tag.