[JENKINS-72453] Groovy Map created via Map#withDefault does not insert unknown keys

[jenkins-infra-bot]

According to the documentation, a Groovy map created using Map#withDefault should add unknown keys referenced via Map#get or Map#[] to the map itself. When executing the below code snippet as a Jenkins pipeline, unknown keys will not be added to the map.

def map = [:].withDefault { [] }
map.get('A') << '1'
map['B'] << '1'

println map.toString() // prints [:], expected [A:[1], B:[1]]
println map.keySet().toString() // prints [], expected [A, B]

Running the same snippet in a regular Groovy interpreter or the Jenkins script console will result in the expected output.

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Originally reported by ailuridae, imported from: Groovy Map created via Map#withDefault does not insert unknown keys

• assignee: vjuranek
• status: Open
• priority: Minor
• component(s): groovy-plugin
• resolution: Unresolved
• votes: 1
• watchers: 2
• imported: 20260604-161841

Raw content of original issue

According to the documentation, a Groovy map created using Map#withDefault should add unknown keys referenced via Map#get or Map#[] to the map itself. When executing the below code snippet as a Jenkins pipeline, unknown keys will not be added to the map.


def map = [:].withDefault { [] }
map.get('A') << '1'
map['B'] << '1'

println map.toString() // prints [:], expected [A:[1], B:[1]]
println map.keySet().toString() // prints [], expected [A, B]


Running the same snippet in a regular Groovy interpreter or the Jenkins script console will result in the expected output.

• environment: Jenkins 2.414.1, Java 11, Groovy 2.4.21

[jenkins-infra-bot]

alejnp:

• Original comment link
• Raw content of original comment:

  I ran into this issue while developing some pipelines which were storing Git Commit IDs after the repositories were cloned. I used `withDefault` because I wanted to store this information based on an conditional other than the cloned repository.
  
  I also tried using the Elvis assignment operator (`?=`) but my Jenkins instance was using Groovy 2 (and I don't know if more recent Jenkins instances use a more up-to-date Groovy). For reference, we're using Jenkins 2.264.
  

I ran into this issue while developing some pipelines which were storing Git Commit IDs after the repositories were cloned. I used `withDefault` because I wanted to store this information based on an conditional other than the cloned repository.

I also tried using the Elvis assignment operator (`?=`) but my Jenkins instance was using Groovy 2 (and I don't know if more recent Jenkins instances use a more up-to-date Groovy). For reference, we're using Jenkins 2.264.