Fix #1623: Decode percent-encoded credentials in URL

[ns-fboucault]

Description

Fixes #1623

HTTPie now properly decodes percent-encoded characters in the username and password when they are provided in the URL's userinfo section.

This allows credentials containing special characters like @, =, and ? to be specified directly in URLs by percent-encoding them, matching the behavior of other HTTP clients like curl.

Changes

• Modified httpie/cli/argparser.py to use urllib.parse.unquote() to decode username and password from URLs
• Added test test_percent_encoded_credentials_in_url() to verify the fix

Example

This now works correctly:

http https://u%40d:1%3d2%[email protected]/basic-auth/u%40d/1%3d2%3f

Where u%40d decodes to u@d and 1%3d2%3f decodes to 1=2?

Testing

• ✅ All existing auth tests pass (31 tests)
• ✅ New test covers the reported issue
• ✅ Manually verified with httpbin.org
• ✅ Backward compatible (non-encoded credentials still work)

Checklist

• [x] Tests added/updated
• [x] All tests passing
• [x] No breaking changes
• [x] Follows existing code style