Values from the pipeline function join() on values emitted by select_jsonpath() include quotes

[miwent]

Using the pipeline function join() on a value emitted by select_jsonpath() results in quote characters being included in the string value.

Expected Behavior

Quote characters are not included in the value emitted by join

Current Behavior

The string values emitted by join() include unwanted quotes when that value was emitted by select_jsonpath

Possible Solution

This issue was previously addressed with a different pipeline function, lookup_all(): #17820

Steps to Reproduce (for bugs)

Paste this rule in the rule simulator and run it to see the output:

rule "test"
when
    true
then
    let j = "{\"test_key\": [ { \"name\": \"widget_10; widget_20\" }, { \"name\": \"widget_30\" } ] }";
    let jp = parse_json ( j );
    let jf = select_jsonpath (
        json: jp,
        paths: {
            __jex: "$.test_key..name"
            }
        );
    set_fields ( jf );
    let jj = join (
        elements: $message.__jex,
        delimiter: ";"
        );
    set_field (
        field: "joined_json_text",
        value: jj
        );

    set_field (
        field: "_direct_text_assignment",
        value: [ "widget_1; widget_2", "widget_3" ]
        );
    let tj = join (
        elements: $message._direct_text_assignment,
        delimiter: ";"
        );
    set_field (
        field: "joined_direct_text",
        value: tj
        );

end

The rule simulator output on Graylog 6.1.3:

Context

Diagnosing this issue was a bit tricky, and the workaround requires an additional step of removing quotes in the output of join().

Your Environment

• Graylog Version: 6.1.3
• Java Version:
• OpenSearch Version:
• MongoDB Version:
• Operating System:
• Browser version: