Between 2.184 and 2.186 it seems to have changed how the /scriptText endpoint returns the data, in 2.186 there are extra newlines at the start of the output which break some of our scripts that use this API to run scripts.

Running the command

curl -X POST https://jenkins/scriptText -F 'script=println "hello"'

produces the following output on 2.184:

hello 

but it produces this on on 2.186:

    hello

(On our servers we use crumb issuer and auth but for the sake of simplicity I omitted those from the curl command as I think it is probably irrelevant wrt the issue).