Possible regression in regular expression custom rule processing

[artu-ole]

Please answer the following questions for yourself before submitting an issue

• Filters were updated before reproducing an issue
• I checked the knowledge base and found no answer
• I checked to make sure that this issue has not already been filed

AdGuard Extension version

4.4.22

Browser version

Brave Version 1.69.160 based on Chromium: 128.0.6613.114

OS version

Win 11

Issue Details

I had several custom rules in the following format which stopped working after a recent update. Here is a simple example of a format of rules I used that had functioned before and does not anymore although having a valid syntax
Steps to reproduce:

1. Add custom rule /api\.github\.com\/\w{5}\/AdguardTeam/
2. Go to https://github.com/AdguardTeam/AdguardBrowserExtension/issues
3. Observe that request to https://api.github.com/users/AdguardTeam was not blocked.

Expected Behavior

expect the request to https://api.github.com/users/AdguardTeam to be blocked

Actual Behavior

request to https://api.github.com/users/AdguardTeam is not blocked

Additional Information

There are very similar rules that do function:

1. if you don't escape the dots in the domain(which is meaningfully different of course):
   /api.github.com\/\w{5}\/AdguardTeam/
2. if you use any char instead of word char(which is also meaningfully different):
   /api\.github\.com\/.{5}\/AdguardTeam/
3. if you wrap word char in capture group(which is not meaningfully different, but why this one works but not the other?):
   /api\.github\.com\/(\w){5}\/AdguardTeam/

I just noticed that my rules stopped working and found those workarounds by trial and error, but I believe original rule breaking is a possible regression