go-yaml does not properly set indent for nodes obtained from in-line JSON

[efd6]

The following program shows that nodes derived from in-line JSON do not properly set their indent, resulting in corrupted output.

https://play.golang.com/p/jxYRN0uVB9J

This returns the following output:

processors:
  - date:
      if: "ctx.event?.timezone == null && ctx._temp_?.raw_date != null"
      target_field: "@timestamp"
      on_failure:
    ppend":
    eld": "error.message", "value": "{{{ _ingest.on_failure_message }}}"}}]

Note that the data is correctly deserialised as can be seen when the data is passed through an any and re-serialised, https://play.golang.com/p/6cCkHpw2MYr.

[efd6]

A work around for this is to apply a mutating visitor to the AST like so https://play.golang.com/p/i3NZO58U-Rs, which should give an indication where the bug is.

type indentVisitor struct{}

func (v indentVisitor) Visit(n ast.Node) ast.Visitor {
	switch n := n.(type) {
	case *ast.MappingValueNode:
		indent := n.GetToken().Position.IndentLevel
		if n.Key.GetToken().Position.IndentLevel <= indent {
			if n, ok := n.Key.(*ast.StringNode); ok {
				n.Token.Position.IndentLevel = indent + 1
			}
		}
	}
	return v
}