On 1st of June, Andrew Dunstan committed patch:
Rename jsonb_replace to jsonb_set and allow it to add new values The function is given a fourth parameter, which defaults to true. When this parameter is true, if the last element of the path is missing in the original json, jsonb_set creates it in the result and assigns it the new value. If it is false then the function does nothing unless all elements of the path are present, including the last. Based on some original code from Dmitry Dolgov, heavily modified by me. Catalog version bumped.
Continue reading Waiting for 9.5 – Rename jsonb_replace to jsonb_set and allow it to add new values