Redmine

Hi,
I am trying to use PUT REST API and changing status_id in a issue.
I want to get error http response in the below situation but I got 200 OK response.

• A issue has child issues which are not completed.
  (In this case, we cannot change parent issue completed status.)
• When we use PUT REST API and try to change parent issue completed.
• parent issue status was not changed but http response is `200 OK`

I tested this curl command:

curl -XPUT -H "content-type: application/json" -H "X-Redmine-Api-Key: xxx" https://redminehost.com/issues/{issueid}.json -d 
'{"issue": {"status_id":96}}' -v

status_id:96 is completed status.

I got this http response:

> PUT /issues/{issueid}.json HTTP/2
> Host: redminehost
> User-Agent: curl/7.54.0
> Accept: */*
> content-type: application/json
> X-Redmine-Api-Key: xxxxxxxxx
> Content-Length: 27
>
* Connection state changed (MAX_CONCURRENT_STREAMS updated)!
* We are completely uploaded and fine
< HTTP/2 200
< date: Mon, 18 Feb 2019 00:59:52 GMT
< content-type: application/json
< server: nginx/1.14.1
< x-frame-options: SAMEORIGIN
< x-xss-protection: 1; mode=block
< x-content-type-options: nosniff
< x-download-options: noopen
< x-permitted-cross-domain-policies: none
< referrer-policy: strict-origin-when-cross-origin
< cache-control: no-cache
< x-request-id: 330ce669-57c2-4e84-8387-92d5b8eab381
< x-runtime: 0.119958
< vary: Origin

Is there any way to get error response when status was not changed ?
I want to know whether status_id was changed or not by http response code.
I would be grateful if you share good way.

My Environment was below:

Environment:
  Redmine version                4.0.1.stable
  Ruby version                   2.6.0-p0 (2018-12-25) [x86_64-linux]
  Rails version                  5.2.2
  Environment                    development
  Database adapter               Mysql2
  Mailer queue                   ActiveJob::QueueAdapters::AsyncAdapter
  Mailer delivery                smtp
SCM:
  Subversion                     1.9.7
  Git                            2.14.5
  Filesystem                     
Redmine plugins:
  no plugin installed

Thanks for helping :)