Countering a removeparam filter causes page-redirect problem

[Yuki2718]

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
• The issue is not present after wholly disabling uBlock Origin ("uBO") in the browser
  • If the issue is still present after wholly disabling uBO in the browser, then the issue is unrelated to uBO
• I tried to reproduce the issue when...
  • uBO is the only extension
  • uBO with default lists/settings
  • using a new, unmodified browser profile
• I checked the documentation to understand that the issue I report is not a normal behavior

Description

Making an exception for a removeparam filter which breaks redirecting causes another issue of page-redirect (apparently only on uBO).

A specific URL where the issue occurs

https://toptechtalk.xyz/?utm_source=socialmedia_uUod
(visit http://turkdebrid.site/api1/?page=create&ads=zshort.io)

Steps to Reproduce

1. Add AdGuard URL Tracking filter: https://filters.adtidy.org/extension/ublock/filters/17.txt
2. Add

@@$removeparam=utm_source,domain=toptechtalk.xyz
@@||toptechtalk.xyz/?utm_source=$removeparam=utm_source,badfilter

to My filters - without this you'll be moved to homepage than the intended destination.
3. Visit http://turkdebrid.site/api1/?page=create&ads=zshort.io

Screenshot

Expected behavior:

You'll be redirected to https://toptechtalk.xyz/is-it-profitable-to-start-an-e-commerce-business-and-earn-money/. This occurs if you unsubscribe AdGuard URL Tracking filter. There's no other parameter involved as far as the logs go.

Actual behavior:

Described

Your environment

• uBlock Origin version: v1.35.2/v1.35.3rc1
• Browser Name and version: Firefox 89.0
• Operating System and version: Windows 10

[Yuki2718]

I added exception to AdGuard URL Tracking filter so please also add @@||toptechtalk.xyz/?utm_source=$removeparam=utm_source,badfilter

[gwarser]

Just these two will be enough?

$removeparam=utm_source
@@$removeparam=utm_source,domain=toptechtalk.xyz

[Yuki2718]

Just these two will be enough?

Yup, reproduced. Commenting out the above filter fixes the problem.

[gorhill]

Looks like Firefox does not validate whether the returned redirectUrl is the same as the current URL, while Chromium does. So the fix is for uBO to do that check.

[gwarser]

Exception is not working at all now? Sorry, caused by different filter. All is fine.