"Merge new fields only" is missing comments

[jandubois]

I'm trying to merge 2 data files, but only want to merge keys from the second file that don't exist in the first. I expect that all comments on copied keys are merged as well.

Version of yq: 4.44.3
Operating system: macOS 12.7.6 (Monterey)
Installed via: homebrew

Input Yamls

empty.yaml:

empty: true

comments.yaml:

# foo head comment
foo: 1 # foo line comment

# bar head comment
bar: # bar line comment
  # baz head comment
  baz: # baz line comment
    # yolo head comment
    yolo: 2 # yolo line comment

Command

yq eval-all -n 'load("empty.yaml") *n load("comments.yaml")'

Actual behavior

empty: true
foo: 1 # foo line comment
bar:
  baz:
    yolo: 2 # yolo line comment

Expected behavior

I expected all the comments to be merged as well. Since none of the fields in comments.yaml exist in empty.yaml the result of *n to be identical to *:

yq eval-all -n 'load("empty.yaml") * load("comments.yaml")'

empty: true
# foo head comment
foo: 1 # foo line comment
# bar head comment
bar: # bar line comment
  # baz head comment
  baz: # baz line comment
    # yolo head comment
    yolo: 2 # yolo line comment

[jandubois]

It looks like the comments attached to the keys are not copied over, probably because they are auto-created when the values are copied.

[mikefarah]

Yep, you are right. I'll need to find spare time to fix this.