Inconsistent behavior between `-mr` and `-er` in v1.9.0 for same regex pattern

[hnvdie]

Description

In httpx v1.9.0, -mr (match regex) does not behave consistently with -er (extract regex) when using the same regex pattern against the same HTTP response.

The same regex is successfully extracted using -er, but -mr does not produce any match.

This behavior is not observed in httpx v1.6.3.

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Steps to Reproduce

Test file

key=AKEBOSHI82HAKA123

Start server

python3 -m http.server 8001

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httpx v1.6.3 (working behavior)

-mr

echo "http://127.0.0.1:8001/test.txt" | ./httpx-v1.6.3 -mr "AKEBOSHI[0-9A-Z]{6}"
http://127.0.0.1:8001/test.txt

-er

echo "http://127.0.0.1:8001/test.txt" | ./httpx-v1.6.3 -er "AKEBOSHI[0-9A-Z]{6}"
http://127.0.0.1:8001/test.txt [AKEBOSHI82HAKA123]

-mr + -er

echo "http://127.0.0.1:8001/test.txt" | ./httpx-v1.6.3 -mr "AKEBOSHI[0-9A-Z]{6}" -er "AKEBOSHI[0-9A-Z]{6}"
http://127.0.0.1:8001/test.txt [AKEBOSHI82HAKA123]

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httpx v1.9.0 (unexpected behavior)

-mr

echo "http://127.0.0.1:8001/test.txt" | ./httpx-v1.9.0 -mr "AKEBOSHI[0-9A-Z]{6}"

(no output)

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-er

echo "http://127.0.0.1:8001/test.txt" | ./httpx-v1.9.0 -er "AKEBOSHI[0-9A-Z]{6}"
http://127.0.0.1:8001/test.txt [AKEBOSHI82HAKA123]

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-mr + -er

echo "http://127.0.0.1:8001/test.txt" | ./httpx-v1.9.0 -mr "AKEBOSHI[0-9A-Z]{6}" -er "AKEBOSHI[0-9A-Z]{6}"

(no output)

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Additional verification

echo "http://127.0.0.1:8001/test.txt" | ./httpx-v1.9.0 -mr "AKEBOSHI"

(no output)

echo "http://127.0.0.1:8001/test.txt" | ./httpx-v1.9.0 -er "AKEBOSHI"
http://127.0.0.1:8001/test.txt [AKEBOSHI82HAKA123]

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Expected behavior

If a regex is successfully matched/extracted from the response body, both:

• -mr should match the response
• -er should extract the same pattern

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Actual behavior

• -er successfully extracts matches from response body
• -mr does not match the same regex in v1.9.0
• Behavior is consistent across regex and literal patterns
• No issue observed in v1.6.3

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Notes

• Test environment is local (python3 -m http.server)
• Response body is confirmed valid and clean
• No encoding issues or hidden characters
• Fully reproducible on both versions