[patrick-immometrica]

Summary

PEP 3333 wants environ strings to hold the raw bytes decoded as latin-1. WSGITransport passed the decoded unicode path as PATH_INFO, and used ascii for header values. With a Flask/werkzeug app:

• GET /caf%C3%A9 -> the app sees /caf�
• GET /euro/%E2%82%AC -> UnicodeEncodeError inside werkzeug
• a non-ASCII request or response header value -> UnicodeDecodeError / UnicodeEncodeError

PATH_INFO is now built from the raw path bytes (unquote_to_bytes on raw_path) and decoded as latin-1, and header values use latin-1 both ways. encode/httpx#1391 fixed the unquoting for this, but not the encoding, so the example in encode/httpx#1365 still failed.

Checklist

• I understand that this PR may be closed in case there was no previous discussion. (This doesn't apply to typos!)
• I've added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• I've updated the documentation accordingly.

[cubic-dev-ai]

All reported issues were addressed across 2 files

<sub>Reply with feedback, questions, or to request a fix.

View guided diff | Re-trigger cubic</sub>

[codspeed]

Merging this PR will not alter performance

✅ 18 untouched benchmarks
⏩ 7 skipped benchmarks¹

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_{Comparing patrick-immometrica:wsgi-latin1 (d3744ef) with main (f4f65c1)}

Footnotes

1. 7 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩