Can't use set-constant.js multiple times for same parent property

[hawkeye116477]

Prerequisites

• I verified that this is not a filter issue
  • Filter issues MUST be reported at filter issue tracker
• This is not a support issue or a question
  • Support issues and questions are handled at /r/uBlockOrigin
• I performed a cursory search of the issue tracker to avoid opening a duplicate issue
  • Your issue may already be reported.
• I tried to reproduce the issue when...
  • uBlock Origin is the only extension
  • uBlock Origin with default lists/settings
  • using a new, unmodified browser profile
• I am running the latest version of uBlock Origin
• I checked the documentation to understand that the issue I report is not a normal behavior

Description

Set-constant.js doesn't work for subdomains.

A specific URL where the issue occurs

[A specific URL is MANDATORY for issue happening on a web page, even if it happens "everywhere"]
https://wiadomosci.wp.pl/

Steps to Reproduce

For example, add this:

wp.pl##script:inject(set-constant.js, WP.crux.set, noopFunc)
||std.wpcdn.pl/wpjslib/*/wpjslib-chunk-notification.js

Then go to wiadomosci.wp.pl and you should not see GDPR message with blur, but it's here. But if you add wiadomosci.wp.pl##script:inject(set-constant.js, WP.crux.set, noopFunc), then everything is ok.

Your environment

• uBlock Origin version: 1.16.14
• Browser Name and version: Chromium 68.0.3440.75
• Operating System and version: Manjaro 17.1.11 Hakoila

[uBlock-user]

GDPR message with blur

Can't reproduce. I don't see any GDPR msg with blur.

noopFunc is also successfully applied as per console -

[hawkeye116477]

If you test with Polish Filter, then you must also test previous version without that long filter open.fm,dobreprogramy.pl,www.wp.pl,wiadomosci.wp.pl,sportowefakty.wp.pl,money.pl,kobieta.wp.pl,gwiazdy.wp.pl,portal.abczdrowie.pl,parenting.pl,moto.wp.pl,tech.wp.pl,horoskop.wp.pl,gry.wp.pl,opinie.wp.pl,turystyka.wp.pl,tv.wp.pl,morizon.wp.pl,komorkomania.pl,gadzetomania.pl,fotoblogia.pl,finanse.wp.pl,pudelek.pl##script:inject(set-constant.js, WP.crux.set, noopFunc) 😄 Also GDPR message may be geolocked.

[gwarser]

I cannot reproduce with or without POL filter list.

[gorhill]

Unable to reproduce:

The proper way to make the case that set-constant.js does not work is not by looking at web page behavior, it's by stepping in code and to show set-constant.js is not being executed. I confirm it is being executed. If the filter does not work after all, it's a filter issue.

[uBlock-user]

If you test with Polish Filter

Then it's a filterlist issue, not a uBO issue. Investigate the cause on your end by disabling all other extensions and reseting to default settings.

Also GDPR message may be geolocked.

The only way I can reproduce the GDPR msg is if I remove the filters you suggested in the STR and refresh the page, so not geolocked either.

[hawkeye116477]

@uBlock-user I tested with default settings and disabled other extensions. If I didn't do that, then I wouldn't check it 😄 But strange is that, I tested again and now it works correct.
But @F4z told me, that he still reproduce that.

[gorhill]

But @F4z told me, that he still reproduce that.

He needs to make the case that the scriptlet is not executing, not that the page behave one way or another. Scriptlets are subject to timing issues, moreso depending on one's environment. For example, the more extensions installed which inject content scripts, the more chance uBO's scriptlets will be injected later, etc. In any case, the important point here is to provide evidence set-constant.js itself does not execute.

[F4z]

First screenshot with wp.pl##script:inject(set-constant.js, WP.crux.set, noopFunc) only, second screenshot when I added wiadomosci.wp.pl##script:inject(set-constant.js, WP.crux.set, noopFunc).

First screenshot

Second screenshot

It's not important to me, so if you can't reproduce it then this issue can be closed.

[gorhill]

so if you can't reproduce

After I enabled POL, I can reproduce the GDPR warning. However after I disabled POL, I confirm that set-constant.js is executed, and I get the warning with both wp.pl or wiadomosci.wp.pl version of the filter:

[gorhill]

How about:

wp.pl##script:inject(cookie-remover.js, STabid)

Seems to work on my side.

[F4z]

Thank you for your answer, I checked it once again and now this rule - wp.pl##script:inject(set-constant.js, WP.crux.set, noopFunc) - works correctly, it's strange, because I didn't change anything.

[F4z]

One more question, I disabled Polish filter list and added these two rules:
pilot.wp.pl##script:inject(set-constant.js, WP.crux.sealed, falseFunc)
pilot.wp.pl##script:inject(set-constant.js, WP.crux.set, noopFunc)
then opened this website - https://pilot.wp.pl/tv and only (the second) one of these rules works (please look on a screenshot).
Is it by design, bug or something wrong on my end?

Screenshot

[gorhill]

I see what the problem is.

[gorhill]

Actually, it just occurred to me that I can simply prevent the targeted property itself to not be configurable while allowing the parent properties leading to the target property to be configurable so as to allow trapping multiple times the same chain of properties (which is what the issue here is about).

[gwarser]

Fixed according to AdguardTeam/AdguardFilters#65244 (comment)

[gwarser]

@gorhill there seems to be one more corner case when one list redefines as null property set by other list as undefined (or vice-versa). Object.defineProperty throws, because property is not configurable (as far as I can understand when stepping through code).

Case is AdguardTeam/AdguardFilters#65519

Add to My filters:

thingiverse.com##+js(set-constant, blockedElement.className, null)
thingiverse.com##+js(set-constant, blockedElement.className, undefined)

Open: https://www.thingiverse.com/thing:2873324.

cc: @krystian3w

---

app.bundle.js?1602608340:2 TypeError: Cannot redefine property: className
    at Function.defineProperty (<anonymous>)
    at trapProp (<anonymous>:208:16)
    at trapChain (<anonymous>:227:13)
    at Object.setter (<anonymous>:265:21)
    at set (<anonymous>:220:25)
    at detected (app.bundle.js?1602608340:2)
    at pr (app.bundle.js?1602608340:2)
    at app.bundle.js?1602608340:2
    at ys (app.bundle.js?1602608340:2)
    at Ul (app.bundle.js?1602608340:2)

---

I don't understand - it works with "", but does not with any other constant. I thought it was only about null and undefined :(

[gorhill]

To fix this would take a lot of non-trivial code, not sure it's worth it if this can be reasonably be fixed in filter lists. Maybe that non-trivial code will occur in some future but for now it's far off.

---

Alright, let me investigate first rather than assume I know exactly what is happening.

[gorhill]

it works with "", but does not with any other constant

"" is not a valid constant, you need to use '', your filter ended up being discarded by using "".

And yes, after investigation, I confirm what I said above.

[addisr]

@gorhill I think this broke this rule. Kinda. Property seems overridden but console says Uncaught TypeError: can't redefine non-configurable property "adblock" and some features of the website are broken.

[gorhill]

@addisr Thanks for feedback. I can reproduce, and I have a fix. Now I wonder if this warrants an emergency fix.

[uBlock-user]

Now I wonder if this warrants an emergency fix.

CNBC is now broken - https://www.reddit.com/r/uBlockOrigin/comments/jeei8n/ublockfilters_is_breaking_cnbc/

[gwarser]

Isn't gorhill/uBlock@2b262b2 actually fixing what I said above in #156 (comment) ?

---

In tree: gorhill/uBlock@5de0ce9

[gorhill]

actually fixing what I said above

I expect this will prevent the throwing at the console, through it won't cause the second filter to work. The more serious issue though is that it was breaking pages doing something like var obj = obj || {}; which should definitely not happen.