How do I consolidate custom fields?

Question

After importing a large number of projects from a redmine instance, I have multiple copies of custom fields that the importer created.  Issues are each using only a single version of the field.  How can I merge those fields together?

Thomas Heidenreich · Accepted Answer

A solution with some effort could be:

* make a backup
* choose one custom field to keep an delete the others including the projects they are used in
* then rename the field to what it is called in the other project(s) and import them one by one

Example:

Project1 uses FieldA
Project2 uses Field_A

* Backup and delete Field_A and Project2
* Rename FieldA to Field_A and import Project2

This could be quite much work if there are many fields and projects involved :(

Or you could use Bob's answer from https://answers.atlassian.com/questions/58231/merging-two-custom-fields ;)