* plugin/file: resolve each additional section target only once
additionalProcessing walked the answer and appended each target's address records without keeping track of the targets it had already resolved. An answer holding several records that point at one target, two MX records differing only in preference for instance, therefore repeated that target's A, AAAA and RRSIGs once per record. SRV, SVCB and HTTPS take the same path and behaved the same way. plugin/backend_lookup.go already skips targets it has seen; the file plugin never did.
Targets are compared in canonical form because SRV targets are not lowercased on insert, so one target can reach additional processing spelled two ways while the zone's tree still matches it case-insensitively. The map is allocated on first use, as additionalProcessing runs for every answer and most carry no target at all.
Fixes#6626
Signed-off-by: baltasarblanco <baltablanco9008@gmail.com>
* plugin/file: move additional section tests to lookup_test.go
The cases exercise additionalProcessing, which lives in lookup.go, so they belong with the rest of the lookup tests. No test logic is changed.
Addresses review feedback.
Signed-off-by: baltasarblanco <baltablanco9008@gmail.com>
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Signed-off-by: baltasarblanco <baltablanco9008@gmail.com>
989bf4a9fd