formula_auditor: handle redis relicense

Signed-off-by: Patrick Linnane <[email protected]>

Library/Homebrew/formula_auditor.rb

@@ -519,6 +519,18 @@ def audit_hashicorp_formulae
  "It must not be upgraded to version #{relicensed_version} or newer."
  end
 
+ # https://redis.com/blog/redis-adopts-dual-source-available-licensing
+ REDIS_RELICENSED_VERSION = "7.4"
+
+ def audit_redis
+ return if formula.name != "redis"
+ return unless @core_tap
+ return if formula.version < Version.new(REDIS_RELICENSED_VERSION)
+
+ problem "Redis was relicensed to a non-open-source license from version 7.4. " \
+ "It must not be upgraded to version 7.4 or newer."
+ end
+
  def audit_keg_only_reason
  return unless @core_tap
  return unless formula.keg_only?