number of filters reduce in custom filters if ublock filters is updated

[BlazeFTL]

Prerequisites

• I verified that this is not a filter list issue. Report any issues with filter lists or broken website functionality in the uAssets issue tracker.
• This is NOT a YouTube, Facebook or Twitch report. These sites MUST be reported by clicking their respective links.
• This is not a support issue or a question. For support, questions, or help, visit /r/uBlockOrigin.
• I performed a cursory search of the issue tracker to avoid opening a duplicate issue.
• The issue is not present after disabling uBO in the browser.
• I checked the documentation to understand that the issue I am reporting is not normal behavior.

I tried to reproduce the issue when...

• uBO is the only extension.
• uBO uses default lists and settings.
• using a new, unmodified browser profile.

Description

https://github.com/user-attachments/assets/55c4d963-27cb-4a94-9b7b-e1c4c71276dc
Screenrecord of the issue

A specific URL where the issue occurs.

*

Steps to Reproduce

1. add trustedListPrefixes ublock- user- https://raw.githubusercontent.com/BlazeFTL/My-Filters/
2. subscribe using https://subscribe.adblockplus.org/?location=https://raw.githubusercontent.com/BlazeFTL/My-Filters/refs/heads/master/My-Filters_Static_Sites.txt&title=My-Filters%20-%20Static%20Sites
3. update BlazeFTL - My Filters for updated filter count
4. update uBlock filters
5. notice BlazeFTL - My Filters filter count decreases..not sure if its just a visual bug
6. If i update BlazeFTL - My Filters again correct filter count is shown

Expected behavior

BlazeFTL - My Filters filter count should not decrease

Troubleshooting information

uBlock Origin: 1.70.0
Firefox: 151
filterset (summary):
 network: 188082
 cosmetic: 228985
 scriptlet: 52631
 html: 3409
listset (total-discarded, last-updated):
 added:
  https://raw.githubusercontent.com/BlazeFTL/My-Filters/refs/heads/master/My-Filters_Static_Sites.txt: 2007-13, 2m
  ublock-experimental: 18-0, 2m
  adguard-mobile: 12337-67, 21h.49m
  adguard-cookies: 37976-80, 21h.48m
  ublock-cookies-adguard: 5646-81, 6d.6h.55m
  fanboy-cookiemonster: 46363-3728, 5d.3m
  ublock-cookies-easylist: 5646-5646, 6d.6h.55m
  adguard-social: 26128-42, 21h.49m
  fanboy-social: 17507-851, 5d.3m
  adguard-popup-overlays: 30749-1009, 21h.49m
  adguard-mobile-app-banners: 7041-105, 21h.49m
  adguard-other-annoyances: 15978-311, 21h.48m
  [7 lists not shown]: [too many]
 default:
  user-filters: 187-0, never
  ublock-filters: 51809-344, 8m
  ublock-badware: 11005-59, 8m
  ublock-privacy: 4006-6, 8m
  ublock-unbreak: 2817-16, 8m
  ublock-quick-fixes: 461-13, 8m
  easylist: 96233-6, 2m
  easyprivacy: 55788-43, 26m Δ
  urlhaus-1: 30140-6, 26m
  plowe-0: 3522-1107, 2m
filterset (user): [array of 97 redacted]
trustedset:
 added: [array of 2 redacted]
userSettings:
 advancedUserEnabled: true
 userFiltersTrusted: true
hiddenSettings:
 filterAuthorMode: true
 trustedListPrefixes: ublock- user- https://raw.githubusercontent.com/BlazeFTL/My-Filters/
supportStats:
 allReadyAfter: 508 ms (selfie)
 maxAssetCacheWait: 128 ms
 cacheBackend: indexedDB

[freezer2022]

Invalid / a duplicate of:

• Can't update filter lists on Firefox for Android  #3947
• "uBlock filters – Cookie Notices" should be separated out just like "uBlock filters – Annoyances" #3467 (comment)
• Prevent cookie lists from being selected at the same time #3231 (comment)
• It seems some filters are not used gorhill/uBlock#2174
• EasyList Not appearing to work "0 used out of 62,821" gorhill/uBlock#1553
• https://github.com/gorhill/uBlock/wiki/Launch-and-filter-lists-load-performance

It's because duplicate filters are always automatically removed by uBO.

[BlazeFTL]

Whatever you referenced did you check the Video?

[freezer2022]

Yes, I did. And I can ask the same: whatever you recorded, have you checked my links?...
If you think that the issue you reported is not the same, then you should present your arguments.

[gorhill]

	Case 1	Case 2	Difference
BlazeFTL	1,995	1,841	+154
uBO filters	69,808	69,972	-164
Total	71803	71813	-10

Having duplicates discarded from different lists is expected given that the lists are loaded in random order, however I would expect no difference in the total.

[BlazeFTL]

70,047
1,841

71888

69,887
1,995

71,882

-6
i thought some of My filters were getting dropped...and i was updating My filters everytime i was updating uBlock filters

[gorhill]

It's not certain that some unduplicated filters are dropped, this could be caused by an issue in how duplicated filters are counted. I first need to reproduce to be able to investigate, and I can't reproduce at the moment, the counts are stable on my side.

[freezer2022]

I can't reproduce at the moment, the counts are stable on my side.

I couldn't reproduce either in the past: #3467 (comment) when someone else has reported similar anomaly, the guess-assumption was that "there were the same duplicated filters in several other lists", but in the current case on the recorded video the other lists's filter count doesn't change, which is quite strange.

---

BlazeFTL: -6 i thought some of My filters were getting dropped...and i was updating My filters everytime i was updating uBlock filters

You're making it sound like that was your original issue, but it wasn't, it looks like you're adjusting your narrative to fit the new facts. That is a different problem you had no idea about, or at least didn't mention in your initial comment. Your original issue was about having duplicates discarded from different list, not about the subtle difference in total filters count.