Fix SOA RNAME email local-part encoding

[ChiragAgg5k]

Summary

• Encode SOA RNAME values supplied in email form, e.g. hostmaster@example.com.
• Preserve dots in the email local part as part of the mailbox label, e.g. first.last@example.com.
• Keep generic Domain::encode() behavior unchanged so the PR only touches the SOA production regression path.

Testing

• ./vendor/bin/phpunit --configuration phpunit.xml --filter 'RecordTest|FileTest'
• php -d memory_limit=512M ./vendor/bin/phpstan analyse --level max -c phpstan.neon src tests
• ./vendor/bin/pint --test --config pint.json

Note: Pint passed, but PHP 8.5 emitted deprecation noise from Pint/Laravel Zero dependencies.

[greptile-apps]

Greptile Summary

This PR fixes SOA RNAME encoding for email-form inputs (e.g. hostmaster@example.com and first.last@example.com) by introducing a dedicated encodeSoaRname helper that splits on @, validates both parts, and encodes the full local part as a single raw DNS label followed by the domain portion encoded via Domain::encode. The change preserves existing behaviour for non-email RNAME values and correctly handles FQDN-terminated domain parts.

• encodeSoaRname correctly embeds the local part (including any dots) as a single length-prefixed label in wire format, consistent with RFC 1035 mailbox encoding, and includes guards for empty parts, multiple @ signs, oversized local-part labels, and total length overflow.
• Two new RecordTest cases and one FileTest integration case exercise the happy paths; both RecordTest methods use assertStringContainsString rather than the full-frame assertSame assertion used by the existing SOA test.

Confidence Score: 5/5

The encoding logic is correct for all common email-form RNAME inputs and backward-compatible with existing DNS-notation RNAME values; the change is safe to merge.

The new encodeSoaRname helper implements RFC 1035 mailbox wire-format encoding faithfully: the local part is placed as a single raw label, length guards match those in Domain::encode, and RDLENGTH is computed dynamically from actual encoded bytes. No logic bugs were found.

The two new RecordTest methods use weaker assertions (assertStringContainsString) than the existing SOA test; they pass but do not verify the complete wire frame.

Important Files Changed

Filename	Overview
src/DNS/Message/Record.php	Adds encodeSoaRname helper that converts email-form RNAME to wire format: splits on @, validates both parts, encodes the local part as a single raw label, then calls Domain::encode for the domain portion. Logic is correct for the common cases; length guards are in place.
tests/unit/DNS/Message/RecordTest.php	Adds two new SOA encoding tests; both use assertStringContainsString (weaker than the existing assertSame full-frame assertion). Test name for the dotted-local-part case is misleading.
tests/unit/DNS/Zone/FileTest.php	Adds an integration test that imports a zone file with an email-form SOA RNAME and verifies the wire encoding contains the expected byte sequence. Covers the FQDN-dot-terminated domain case correctly.

_{Reviews (3): Last reviewed commit: "Narrow SOA RNAME email encoding fix" | Re-trigger Greptile}