Pre-Defined parameters no longer passed to child job - jenkins

Question

I upgraded Jenkins today from 1.618 to 2.3. This included installing a whole bunch of plugins that it recommended (Mostly Pipeline plugins and their dependencies).
Since the upgrade, I get a new error (or, at least, a new unwanted behavior) any time a job kicks off another job. Any values passed to the child as "Predefined parameters" are ignored unless the child job already has those keys defined.
Let me illustrate: Let's say that I have a parent job and a child job.
Parent launches child through a "Trigger parameterized build on other projects" Post-build Action. In the definition of that Post-build Action, under the "Predefined parameters", I have FOO=BAR defined.
In Jenkins 1.618, when child was triggered this way, it would have FOO set as a parameter, with a value of BAR.
But in 2.3, FOO is not set on that build of child.
If I modify child so that FOO is always a parameter of that job, it will then pick up the FOO=BAR set from parent. This is an unacceptable work-around because we pass dozens of parameters this way, and defining them on both ends is too fragile and violates the "don't repeat yourself" principle.
I get the same results whether I'm triggering the child job through through the "Trigger parameterized build on other projects" Post-build Action or through a MultiJob Phase of a MultiJob project.
Is this an intended change? Was it broken before, and we were just using it incorrectly? Or is this a bug?

Answer 1

According to Jenkins 2 Security updates, you can bypass it by setting:
hudson.model.ParametersAction.keepUndefinedParameters=true
To validate this workaround, go to Manage Jenkins -> Script Console, and run:
System.setProperty("hudson.model.ParametersAction.keepUndefinedParameters", "true")
To make it permanent, change Jenkins arguments as follow (and restart Jenkins afterwards):
On Windows edit jenkins.xml in Jenkins home directory, for example:
<arguments>
-Xrs -Xmx256m -Dhudson.lifecycle=hudson.lifecycle.WindowsServiceLifecycle
-Dhudson.model.ParametersAction.keepUndefinedParameters=true
-jar "%BASE%\jenkins.war" --httpPort=8080
</arguments>
For most of the Linux distributions, you can modify JENKINS_ARGS inside file:
/etc/default/jenkins (or jenkins-oc)
For CentOS, modify JENKINS_JAVA_OPTIONS inside file:
/etc/sysconfig/jenkins (or jenkins-oc)
Here's a list of reported plugins, that were affected by the issue, and has an open bug already:
https://wiki.jenkins-ci.org/display/JENKINS/Plugins+affected+by+fix+for+SECURITY-170

Answer 2

There are some solutions
commabd line
java -Dhudson.model.ParametersAction.keepUndefinedParameters=true -jar jenkins.war
groovy
import jenkins.model.*;
System.setProperty("hudson.model.ParametersAction.keepUndefinedParameters", "true")

Answer 3

I couldn't find a Start-to-End answer on how to set this for a linux box. After a couple hours of cross-referencing guides, this is what ended up working. There are supposed to be a couple flavors of these Jenkins configurations. I'm using the Ubuntu flavor for this answer.
Get the Groovy scripting plugin
Discern where your $JENKINS_HOME is being set. By default, it's supposed to be at ~/.jenkins, but I didn't set this server up, so I had to go digging through some configuration files. In case you do too, this is what I had to do:
Check the contents of /etc/default/jenkins with vi to grab the value of $JENKINS_HOME -- mine was /var/lib/$NAME and further up the file, $NAME was set to jenkins, so it was /etc/libs/jenkins
Change directories to the $JENKINS_HOME path
Search for a directory called init.groovy.d -- if it doesn't exist, make one and then cd into it. You might have to use sudo if needing to make it
Create a new file in the init.groovy.d directory that ends in .groovy -- I just called mine params.groovy
Enter following script code into the groovy file we just made:
import jenkins.model.*;
System.setProperty("hudson.model.ParametersAction.keepUndefinedParameters", "true")
Save and Close, then reboot your Jenkins server.
That should unblock you, if you ran into the same problem I did. Your mileage may vary :) I ultimately used a start-up script to utilize that functionality in conjunction with this solution proposed by Jenkins.