logging: hash query parameter values in QueryFilter

[PichuChen]

Fixes #7883.

Summary

The query log filter currently passes the hash action's Value field to hash. Because a hash action does not populate that field, every query parameter value is replaced with the hash of an empty string (e3b0c442).

This change:

• hashes each actual query parameter value;
• updates the existing single-value test to expect the hash of its input;
• uses distinct inputs in the multi-value test to verify that different values produce different hashes.

The behavior is now consistent with the query filter documentation and with the cookie filter, which already hashes the actual cookie value.

Testing

The updated tests failed against the original implementation with e3b0c442, then passed after the production-code change.

The following commands completed successfully:

go test ./modules/logging \
  -run 'TestQueryFilter(SingleValue|MultiValue)$' \
  -count=1

go test ./modules/logging -count=1

go test -race ./modules/logging -count=1

go test \
  -coverprofile=/tmp/caddy-cover-profile.out \
  -short \
  -race \
  ./... \
  -count=1

Assistance Disclosure

AI-assisted using OpenAI Codex (GPT-5).

The issue was initially identified with AI assistance while reviewing a downstream Caddy configuration. I independently reproduced the behavior against unmodified v2.11.4 and current master checkouts, inspected and understood the relevant implementation, verified the SHA-256 results, and performed a red-green regression-test workflow.

AI assisted with the initial analysis, test planning, and wording. I reviewed and understand the code and tests in this pull request.

[CLAassistant]

All committers have signed the CLA.

[Copilot]

Pull request overview

Agent review by GitHub Copilot.

This pull request fixes QueryFilter’s hash action so it hashes each actual query parameter value (instead of always hashing an empty string), aligning behavior with the documentation and the existing cookie filter.

Changes:

• Update QueryFilter.processQueryString to hash q[a.Parameter][i] (the actual per-value input) rather than a.Value.
• Update the single-value query filter test to expect the SHA-256 prefix of the real input.
• Strengthen the multi-value test by using distinct inputs (alpha/beta) and asserting distinct expected hashes.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
modules/logging/filters.go	Fixes query parameter hashing to use the real parameter value.
modules/logging/filters_test.go	Updates/strengthens tests to validate correct per-value hashing behavior.

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