Copying Language dependent Data when Primary language changed

Hi guys,

We have started some of this discussion back in 2009 here

I believe we should COPY the Language dependent Data when Primary language
is changed.

Scenario:

1. Fresh install (ie. 5.1.0-RC1 or whatever) with Advanced theme.

2. Import French lang. pack and set it as Primary right there (no Logins)

3. Added a few new Sections (former Categories) in the Catalog.

In result I have Lot of Sections missing Primary Language value (for French)
since were created before French became primary.

Some attachments to explain better.

I propose to copy the data for all "l[n]_" fields from prev. Primary to new
Primary for those which are NULL (or are empty).

DA.