I've tried the source code and it seems to work as it was expected. However, as it's written in https://community.kde.org/Policies/Commit_Policy#Special_keywords_in_GIT_and_SVN_log_messages : in the diff a "BUG: <bugnumber>" line should exist, and finally a "Differential Revision: https://phabricator.kde.org/D<number>" line. You can add those lines after executing git commit -a, and with e.g. git show > file.diff the diff file would contain those messages.
Or, even better, use kconf_update to automatically migrate the setting to the new name, with no need to add fallback code to the application itself.
You can find examples of scripts for kconf_update in many applications, e.g. kmail, konversation, kontact, okular, tellico, kget, kcalc, akregator, gwenview, kile, etc.
Hi Pino, Thanks for the suggestion. I didn't know about the tool. I briefly read the doc and found
Updating the configuration happens automatically, either when KDE gets started or when kded detects a new update file in the above mentioned location.
which means non-KDE users are out of luck. Am I right?