Common filter options are executed multiple times

[poulinjulien]

• Version: 6.4.2
• Operating System: RHEL
• Config File:

  
  input {
  generator {
  lines => [
    "1|2:3"
  ]
  count => 1
  }
  }

filter { dissect { mapping => { "message" => "%{a}|%{b}" "b" => "%{c}:%{d}" } add_field => {"e" => "%{b}"} } }

output { stdout { codec => rubydebug } }

- Expected output:

{ "a": "1", "b": "2:3", "c": "2", "d": "3", "e": "2:3" }

- Actual output:

{ "a": "1", "b": "2:3", "c": "2", "d": "3", "e": [ "2:3", "2:3" ] }

[guyboertje]

Confirmed on 7.0.0 too.

Investigating.