This is a change from the pre-1.5 behavior, which would return the default value for some fields even if they were not present in the json. ([#37991](https://github.com/kubernetes/kubernetes/pull/37991), [@pwittrock](https://github.com/pwittrock))

* The strategicmerge patchMergeKey for VolumeMounts was changed from "name" to "mountPath".  This was necessary because the name field refers to the name of the Volume, and is not a unique key for the VolumeMount.  Multiple VolumeMounts will...

succeeded except for the part where the new replication controller is renamed back to the old name. You can just do another rolling update using kubectl 1.4 or higher to change the name back: look for a replication controller that has the original name plus a random suffix.

Unfortunately, there is a much rarer second possible failure mode: the replication controller gets renamed to the old name, but there is a duplicated set of pods in the cluster. kubectl will not report an error since...

   ([#123611](https://github.com/kubernetes/kubernetes/pull/123611), [@ritazh](https://github.com/ritazh))