[rusetiq]

What type of PR is this?

• Bug Fix

Description

fragment_identifier_matcher('flag=&value=1') currently accepts #value=1, and fragment_identifier_matcher('flag=') accepts #other= or no fragment. parse_qsl drops blank values by default, so these distinct fragments become equal after parsing.

Retain blank values when parsing both expected and actual query-string-style fragments. Parameter order remains insignificant, while blank parameter names and multiplicity are checked. Opaque fragment matching is unchanged.

Add eight direct matcher cases and a requests integration test covering missing, different, reordered, and duplicate parameters. Five regression cases fail before the fix; all pass afterward.

Related Issues

No existing issue identified for this specific case.

PR checklist

• Read the contributing guidelines
• Ran tox and pre-commit checks locally
• Added my changes to CHANGES

Validation on macOS / Python 3.13.14:

• Ran the pytest command from tox: python -m pytest . --asyncio-mode=auto --cov responses --cov-report term-missing -q: 261 passed, 99% overall coverage.
• All configured pre-commit hooks passed for the changed files.
• Both configured mypy invocations were run with mypy 2.4.0. They report three existing diagnostics (two in matchers.py and one in test_recorder.py), also reproduced on an unchanged archive of the upstream commit. This change adds none.
• git diff --check passed.

The complete multi-version tox matrix was not run locally.

Added/updated tests?

• Yes

This contribution was prepared with assistance from OpenAI Codex.