Issue Summary

This is reproducible on Data Center: yes

In Jira 10, for the “Issue Link” REST API, the “Content Type” in the Response Header has changed from “application/json;charset=UTF-8” to “text/html;charset=UTF-8" when compared with Jira 9.

Steps to Reproduce

1. Setup a Jira 10 instance.
2. Create a Project. Then create 2 issues in that Project.
3. Send a REST Post Call as below to link the two issues.
   REST EndPoint is- 

   rest/api/2/issueLink 

   As seen in the Response Header, the "Content type" is "text/html;charset=UTF-8"
   

In Jira 9.x

When the same Rest End Point is checked on a Jira 9 version instance, the "Content type" in the Response Header is "application/json;charset=UTF-8"

Expected Results

“Content Type” in the Response Header for “Issue Link” REST API is expected to be "application/json;charset=UTF-8"

Actual Results

“Content Type” in the Response Header for “Issue Link” REST API is returned as “text/html;charset=UTF-8"

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available