As discovered in https://github.com/jbosstools/jbosstools-openshift/pull/1106#issuecomment-208542930, provided you have a docker and an OpenShift connection:

• In OpenShift Explorer, select the Deploy Image menu
• select the docker connection
• type a docker image name already pulled in the docker daemon
• delete it and click the search... button
• select the same docker image as previously typed
• once the search wizard closes, the docker Image name field is still empty.

See http://screencast.com/t/iTJX7SjB

As per scabanovich:

it is possible that validator does not let empty string to model, so model remains with valid previous value. Then, when you select that same value in the dialog, model is notified, but it already has that value and it does not notify ui because it did not change

and his fix proposal:

before calling setImageName(newValue) check if it has the same value, then call setImageName(""); and only after this check and adjustment call setImageName(newValue).