set-cookie scriptlet can cause uncaught error when cookie path / is explicitly specified

[tan-x-y]

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

When adding a set-cookie scriptlet filter to My filters that explicitly specifies the cookie path / while using a regex‑based hostname (or when converting an existing plain hostname filter into a regex‑based one), uBO editor throws an uncaught error and fails to render the filter line. For example:

/example\.com/##+js(set-cookie, cookie, accept, /)

Attempting to edit such a filter in My filters immediately triggers:

Uncaught Error: Mode ubo-static-filtering failed to advance stream.

A specific URL where the issue occurs.

extension://odfafepnkmbhccpbejgmiehpchacaeak/dashboard.html#1p-filters.html

Steps to Reproduce

1. Add a filter using a regex hostname and explicit cookie path to My filters:

/example\.com/##+js(set-cookie, cookie, accept, /)

2. Observe the uncaught error in the console.

Expected behavior

No error

Troubleshooting information

uBlock Origin: 1.74.0
Chromium: 152
filterset (summary):
 network: 184367
 cosmetic: 43712
 scriptlet: 37702
 html: 0
listset (total-discarded, last-updated):
 default:
  user-filters: 0-0, never
  ublock-filters: 53295-85, 1m
  ublock-badware: 10395-17, 1m
  ublock-privacy: 4147-4, 1m
  ublock-unbreak: 2803-1, 1m
  ublock-quick-fixes: 504-0, 1m
  easylist: 88469-489, 1m
  easyprivacy: 56531-739, 1m
  urlhaus-1: 47575-11, 1m
  plowe-0: 3540-2, 2m
filterset (user): [empty]
userSettings: [none]
hiddenSettings: [none]
supportStats:
 allReadyAfter: 3027 ms
 maxAssetCacheWait: 18 ms
 cacheBackend: indexedDB

[gorhill]

Issue is unrelated to set-cookie scriptlet. Minimal steps to reproduce:

• Add example.com##+js(a, /)
• Prepend / before example.com

The issue is that the domain parsing would include everything between the first / to the next /, which is beyond the list of domains.